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Ebhodaghe FI, Sanchez-Vargas I, Isaac C, Foy BD, Hemming-Schroeder E. Sibling species of the major malaria vector Anopheles gambiae display divergent preferences for aquatic breeding sites in southern Nigeria. Malar J 2024; 23:60. [PMID: 38413961 PMCID: PMC10900747 DOI: 10.1186/s12936-024-04871-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND When integrated with insecticide-treated bed nets, larval control of Anopheles mosquitoes could fast-track reductions in the incidence of human malaria. However, larval control interventions may deliver suboptimal outcomes where the preferred breeding places of mosquito vectors are not well known. This study investigated the breeding habitat choices of Anopheles mosquitoes in southern Nigeria. The objective was to identify priority sites for mosquito larval management in selected urban and periurban locations where malaria remains a public health burden. METHODS: Mosquito larvae were collected in urban and periurban water bodies during the wet-dry season interface in Edo, Delta, and Anambra States. Field-collected larvae were identified based on PCR gel-electrophoresis and amplicon sequencing, while the associations between Anopheles larvae and the properties and locations of water bodies were assessed using a range of statistical methods. RESULTS Mosquito breeding sites were either man-made (72.09%) or natural (27.91%) and mostly drainages (48.84%) and puddles (25.58%). Anopheles larvae occurred in drainages, puddles, stream margins, and a concrete well, and were absent in drums, buckets, car tires, and a water-holding iron pan, all of which contained culicine larvae. Wild-caught Anopheles larvae comprised Anopheles coluzzii (80.51%), Anopheles gambiae sensu stricto (s.s.) (11.54%), and Anopheles arabiensis (7.95%); a species-specific PCR confirmed the absence of the invasive urban malaria vector Anopheles stephensi among field-collected larvae. Anopheles arabiensis, An. coluzzii, and An. gambiae s.s. displayed preferences for turbid, lowland, and partially sunlit water bodies, respectively. Furthermore, An. arabiensis preferred breeding sites located outside 500 m of households, whereas An. gambiae s.s. and An. coluzzii had increased detection odds in sites within 500 m of households. Anopheles gambiae s.s. and An. coluzzii were also more likely to be present in natural water bodies; meanwhile, 96.77% of An. arabiensis were in man-made water bodies. Intraspecific genetic variations were little in the dominant vector An. coluzzii, while breeding habitat choices of populations made no statistically significant contributions to these variations. CONCLUSION Sibling malaria vectors in the An. gambiae complex display divergent preferences for aquatic breeding habitats in southern Nigeria. The findings are relevant for planning targeted larval control of An. coluzzii whose increasing evolutionary adaptations to urban ecologies are driving the proliferation of the mosquito, and An. arabiensis whose adults typically evade the effects of treated bed nets due to exophilic tendencies.
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Affiliation(s)
- Faith I Ebhodaghe
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Irma Sanchez-Vargas
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Clement Isaac
- Department of Zoology, Faculty of Life Sciences, Ambrose Alli University, Ekpoma, Edo State, Nigeria
| | - Brian D Foy
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Elizabeth Hemming-Schroeder
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA.
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Yovogan B, Sovi A, Djènontin A, Adoha CJ, Akinro B, Accrombessi M, Dangbénon E, Koukpo CZ, Affolabi ZK, Agboho PA, Kpanou CD, Assongba L, Missihoun AA, Tokponnon TF, Agbangla C, Padonou GG, Messenger LA, Ngufor C, Cook J, Akogbéto MC, Protopopoff N. The impact of pyrethroid-pyriproxyfen and pyrethroid-chlorfenapyr long-lasting insecticidal nets on density of primary malaria vectors Anopheles gambiae s.s. and Anopheles coluzzii in Benin: a secondary analysis of a cluster randomised controlled trial. Parasit Vectors 2024; 17:7. [PMID: 38178161 PMCID: PMC10768265 DOI: 10.1186/s13071-023-06104-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/17/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) may have different impacts on distinct mosquito vector species. We assessed the efficacy of pyrethroid-pyriproxyfen and pyrethroid-chlorfenapyr LLINs on the density of Anopheles gambiae s.s. and An. coluzzii compared to pyrethroid-only nets in a three-arm cluster randomised control trial in Benin. METHODS Indoor and outdoor collections of adult mosquitoes took place in 60 clusters using human landing catches at baseline and every 3 months for 2 years. After morphological identification, around 15% of randomly selected samples of An. gambiae s.l. were dissected to determine parity, species (using PCR). RESULTS Overall, a total of 46,613 mosquito specimens were collected at baseline and 259,250 in the eight quarterly collections post-net distribution. Post-net distribution, approximately 70% of the specimens of An. gambiae s.l. speciated were An. coluzzii, while the rest were mostly composed of An. gambiae s.s. with a small proportion (< 1%) of hybrids (An. gambiae/coluzzii). There was no evidence of a significant reduction in vector density indoors in either primary vector species [An. coluzzii: DR (density ratio) = 0.62 (95% CI 0.21-1.77), p = 0.3683 for the pyrethroid-pyriproxyfen LLIN and DR = 0.56 (95% CI 0.19-1.62), p = 0.2866 for the pyrethroid-chlorfenapyr LLIN, An. gambiae s.s.: DR = 0.52 (95% CI 0.18-1.46), p = 0.2192 for the pyrethroid-pyriproxyfen LLIN and DR = 0.53 (95% CI 0.19-1.46), p = 0.2222 for the pyrethroid-chlorfenapyr]. The same trend was observed outdoors. Parity rates of An. gambiae s.l. were also similar across study arms. CONCLUSIONS Compared with pyrethroid-only LLINs, pyrethroid-chlorfenapyr LLINs and pyrethroid-pyriproxyfen LLINs performed similarly against the two primary mosquito species An. gambiae s.s. and An. coluzzii in Benin.
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Affiliation(s)
- Boulais Yovogan
- Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Abomey-Calavi, Benin.
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.
| | - Arthur Sovi
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.
- Faculté d'Agronomie, Université de Parakou, Parakou, Benin.
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, The London School of Hygiene and Tropical Medicine, London, UK.
| | - Armel Djènontin
- Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Constantin J Adoha
- Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Bruno Akinro
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Manfred Accrombessi
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, The London School of Hygiene and Tropical Medicine, London, UK
| | | | - Come Z Koukpo
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | | | | | | | - Landry Assongba
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | | | - Tatchémè Filémon Tokponnon
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Ecole Polytechnique d'Abomey-Calavi, Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Clément Agbangla
- Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Germain Gil Padonou
- Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Louisa A Messenger
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, The London School of Hygiene and Tropical Medicine, London, UK
- Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, NV, 89154, USA
| | - Corine Ngufor
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, The London School of Hygiene and Tropical Medicine, London, UK
| | - Jackie Cook
- Medical Research Council (MRC) International Statistics and Epidemiology, Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Natacha Protopopoff
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, The London School of Hygiene and Tropical Medicine, London, UK
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Gueye OK, Niang A, Faye MB, Dia AK, Ahmed AA, Sy O, Tripet F, Konaté L, Dia I, Wondji CS, Gaye O, Faye O, Diabate A, Niang EHA. Characterization of the swarming behavior of Anopheles coluzzii and Anopheles gambiae (Diptera: Culicidae) populations in a hybrid zone of Senegal. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:1278-1287. [PMID: 37738317 DOI: 10.1093/jme/tjad120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 08/14/2023] [Accepted: 08/19/2023] [Indexed: 09/24/2023]
Abstract
Anopheles gambiae and Anopheles coluzzii, often found in sympatry and synchronous, have undergone a premating reproductive isolation across their distribution range. However, in the Western coast of Africa, unexpected hybridization zones have been observed, and little is known about swarming behavior of these cryptic taxa. Here, we characterized the swarming behavior of An. coluzzii and An. gambiae to investigate its role in the high hybridization level in Senegal. The study was conducted in the south and central Senegal during the 2018 rainy season. Mating swarms of malaria vectors were surveyed at sunset and collected using an insect net. Meanwhile, indoor resting populations of malaria vectors were collected by pyrethrum spray catches. Upon collection, specimens were identified morphologically, and then members of the An. gambiae complex were identified at the species level by polymerase chain reaction (PCR). An. gambiae swarmed mainly over bare ground, whereas An. coluzzii were found swarming above various objects creating a dark-light contrast with the bare ground. The swarms height varied from 0.5 to 2.5 m. Swarming starting time was correlated with sunset whatever the months for both species, and generally lasted about 10 min. No mixed swarm of An. gambiae and An. coluzzii was found even in the high hybridization area. These results indicated a premating isolation between An. coluzzii and An. gambiae. However, the high hybridization rate in the sympatric area suggests that heterogamous mating is occurring, thus stressing the need for further extensive studies.
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Affiliation(s)
- Oumou Kalsom Gueye
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
| | - Abdoulaye Niang
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
- Institut de Recherche en Sciences de la Santé (IRSS), BP 545 Bobo-Dioulasso, Burkina Faso
| | - Mouhamed Bassir Faye
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
| | - Abdoulaye Kane Dia
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
| | - Amblat Ali Ahmed
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
| | - Ousmane Sy
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
| | - Frederic Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, UK
| | - Lassana Konaté
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
| | - Ibrahima Dia
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220 Dakar, Senegal
| | - Charles Sinclair Wondji
- Centre for Research in Infectious diseases (CRID), Yaounde, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool,UK
| | - Oumar Gaye
- Service de parasitologie-mycologie, faculté de médecine, pharmacie et d'odontologie, Université Cheikh Anta Diop, Dakar, Senegal
| | - Ousmane Faye
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
| | - Abdoulaye Diabate
- Institut de Recherche en Sciences de la Santé (IRSS), BP 545 Bobo-Dioulasso, Burkina Faso
| | - El Hadji Amadou Niang
- Laboratoire d'Écologie Vectorielle et Parasitaire, Département de Biologie Animale, Université Cheikh Anta Diop, Dakar, Senegal
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Mahenge HH, Muyaga LL, Nkya JD, Kifungo KS, Kahamba NF, Ngowo HS, Kaindoa EW. Common predators and factors influencing their abundance in Anopheles funestus aquatic habitats in rural south-eastern Tanzania. PLoS One 2023; 18:e0287655. [PMID: 37363899 DOI: 10.1371/journal.pone.0287655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 06/10/2023] [Indexed: 06/28/2023] Open
Abstract
BACKGROUND The role of larval predators in regulating the Anopheles funestus population in various malaria-endemic countries remains relatively unknown. This study aimed to investigate the common predators that co-exist with Anopheles funestus group larvae and evaluate factors that influence their abundance in rural south-eastern Tanzania. METHODS Mosquito larvae and predators were sampled concurrently using standard dipper (350 ml) or 10 L bucket in previously identified aquatic habitats in selected villages in southern Tanzania. Predators and mosquito larvae were identified using standard identification keys. All positive habitats were geo-located and their physical features characterized. Water physicochemical parameters such as dissolved oxygen (DO), pH, electrical conductivity (EC), total dissolved solids (TDS) and temperature were also recorded. RESULTS A total of 85 previously identified An. funestus aquatic habitats in nine villages were sampled for larvae and potential predators. A total of 8,295 predators were sampled. Of these Coenagrionidae 57.7% (n = 4785), Corixidae 12.8% (n = 1,060), Notonectidae 9.9% (n = 822), Aeshnidae 4.9% (n = 405), Amphibian 4.5% (n = 370), Dytiscidae 3.8% (n = 313) were common. A total of 5,260 mosquito larvae were sampled, whereby Anopheles funestus group were 60.3% (n = 3,170), Culex spp. 24.3% (n = 1,279), An. gambie s.l. 8.3% (n = 438) and other anophelines 7.1% (n = 373). Permanent and aquatic habitats larger than 100m2 were positively associated with An. funestus group larvae (P<0.05) and predator abundance (P<0.05). Habitats with submerged vegetation were negatively associated with An. funestus group larvae (P<0.05). Only dissolved oxygen (DO) was positively and significantly affect the abundance of An. funestus group larvae (P<0.05). While predators' abundance was not impacted by all physicochemical parameters. CONCLUSION Six potential predator families were common in aquatic habitats of An. funestus group larvae. Additional studies are needed to demonstrate the efficacy of different predators on larval density and adult fitness traits. Interventions leveraging the interaction between mosquitoes and predators can be established to disrupt the transmission potential and survival of the An. funestus mosquitoes.
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Affiliation(s)
- Herieth H Mahenge
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- The Nelson Mandela, African Institution of Science and Technology, School of Life Sciences and Bio Engineering, Tengeru, Arusha, United Republic of Tanzania
| | - Letus L Muyaga
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Joel D Nkya
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Khamis S Kifungo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Najat F Kahamba
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- School of Biodervisty, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Halfan S Ngowo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- School of Biodervisty, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Emmanuel W Kaindoa
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- The Nelson Mandela, African Institution of Science and Technology, School of Life Sciences and Bio Engineering, Tengeru, Arusha, United Republic of Tanzania
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
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5
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Padonou GG, Zoungbédji DM, Sovi A, Salako AS, Konkon AK, Yovogan B, Adoha CJ, Odjo EM, Osse R, Sina H, Govoétchan R, Kpanou CD, Sagbohan HW, Baba-Moussa L, Akogbéto M. Trophic preferences of Anopheles coluzzii (Diptera: Culicidae): what implications for malaria vector control in Benin? JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:554-563. [PMID: 36939048 DOI: 10.1093/jme/tjad017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/14/2023] [Accepted: 02/03/2023] [Indexed: 05/13/2023]
Abstract
The main objective of the present study is to assess the preferences in terms of vertebrate hosts of Anopheles coluzzii, the main malaria vector in the pastoral area of Malanville, Benin, where rice cultivation and livestock are the main source of income for the populations. Adult mosquitoes were collected through pyrethrum spray catch, and human landing catch in two communes in Benin: Malanville, a pastoral area, and Porto-Novo, a nonpastoral area. Molecular species identification was performed through PCR within the Anopheles gambiae complex. Blood meal origin and P. falciparum sporozoite infection were determined using ELISA blood meal and circumsporozoite protein tests, respectively. Overall, 97% of females of An. gambiae s.l. were An. coluzzii, with biting behavior more pronounced outdoors in the pastoral area. In Malanville, the main vertebrate hosts on which females An. coluzzii blood fed were goats (44%), humans (24.29%), bovines (22%), and pigs (1.4%). Our results also showed that single-host blood meals (human: 24.29% or animal: 68%) were mostly observed compared to mixed blood meals (8.58%). The human biting rate (HBR) and P. falciparum sporozoite rate (SR) of An. coluzzii were 66.25 bites/man/night and 0.77%, respectively. However, in the nonpastoral zone (Porto-novo), 93.98% of samples were An. coluzzii. The latter blood-fed mostly (86.84%) on humans, with an estimated HBR of 21.53 b/m/n and SR of 5.81%. The present study revealed an opportunistic and zoophagic behavior of An. coluzzii in the Malanville area with an overall low mean SR.
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Affiliation(s)
- Germain Gil Padonou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - David Mahouton Zoungbédji
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Arthur Sovi
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculty of Agronomy, University of Parakou, Parakou, Benin
- Faculty of Infectious and Tropical Diseases, The London School of Hygiene and Tropical Medicine, London, UK
| | | | - Alphonse Keller Konkon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Boulais Yovogan
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Constantin Jesukèdè Adoha
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Esdras Mahoutin Odjo
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Razaki Osse
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- École de gestion et d'exploitation des systèmes d'élevage, Université Nationale d'Agriculture de Porto-Novo, Porto-Novo, Bénin
| | - Haziz Sina
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cellular Biology, Abomey-Calavi, Benin
| | - Renaud Govoétchan
- Faculty of Agronomy, University of Parakou, Parakou, Benin
- Faculty of Infectious and Tropical Diseases, The London School of Hygiene and Tropical Medicine, London, UK
| | - Casimir Dossou Kpanou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Hermann W Sagbohan
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Lamine Baba-Moussa
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
- Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cellular Biology, Abomey-Calavi, Benin
| | - Martin Akogbéto
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
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Apetogbo Y, Ahadji-Dabla KM, Soma DD, Amoudji AD, Koffi E, Akagankou KI, Bamogo R, Ngaffo KL, Maiga S, Atcha-Oubou RT, Dorkenoo AM, Vizcaino L, Lenhart A, Diabaté A, Dabiré RK, Ketoh GK. Insecticide resistance intensity and efficacy of synergists with pyrethroids in Anopheles gambiae (Diptera: Culicidae) from Southern Togo. Malar J 2022; 21:353. [PMID: 36437444 PMCID: PMC9703766 DOI: 10.1186/s12936-022-04377-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/10/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND This study was designed to provide insecticide resistance data for decision-making in terms of resistance management plans in Togo. METHODS The susceptibility status of Anopheles gambiae sensu lato (s.l.) to insecticides used in public health was assessed using the WHO tube test protocol. Pyrethroid resistance intensity bioassays were performed following the CDC bottle test protocol. The activity of detoxification enzymes was tested using the synergists piperonyl butoxide, S.S.S-tributlyphosphorotrithioate and ethacrinic acid. Species-specific identification of An. gambiae s.l. and kdr mutation genotyping were performed using PCR techniques. RESULTS Local populations of An. gambiae s.l. showed full susceptibility to pirimiphos methyl at Lomé, Kovié, Anié, and Kpèlè Toutou. At Baguida, mortality was 90%, indicating possible resistance to pirimiphos methyl. Resistance was recorded to DDT, bendiocarb, and propoxur at all sites. A high intensity of pyrethroid resistance was recorded and the detoxification enzymes contributing to resistance were oxidases, esterases, and glutathione-s-transferases based on the synergist tests. Anopheles gambiae sensu stricto (s.s.) and Anopheles coluzzii were the main species identified. High kdr L1014F and low kdr L1014S allele frequencies were detected at all localities. CONCLUSION This study suggests the need to reinforce current insecticide-based malaria control interventions (IRS and LLINs) with complementary tools.
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Affiliation(s)
- Yawo Apetogbo
- Laboratoire d'Ecologie et d'Ecotoxicologie, Faculté des Sciences, Université de Lomé, 01 B.P. 1515, Lomé 01, Togo. .,Institut de Recherche en Sciences de la Santé/Centre Muraz, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso. .,Centre d'Excellence Africaine d'Innovation biotechnologique pour l'Elimination des Maladies à Transmission Vectorielle (CEA-ITECH-MTV), Université Nazi Boni, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso.
| | - Koffi M Ahadji-Dabla
- Laboratoire d'Ecologie et d'Ecotoxicologie, Faculté des Sciences, Université de Lomé, 01 B.P. 1515, Lomé 01, Togo.
| | - Dieudonné Diloma Soma
- Institut de Recherche en Sciences de la Santé/Centre Muraz, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso
| | - Adjovi D Amoudji
- Laboratoire d'Ecologie et d'Ecotoxicologie, Faculté des Sciences, Université de Lomé, 01 B.P. 1515, Lomé 01, Togo
| | - Edoh Koffi
- Laboratoire d'Ecologie et d'Ecotoxicologie, Faculté des Sciences, Université de Lomé, 01 B.P. 1515, Lomé 01, Togo
| | - Kossivi I Akagankou
- Laboratoire d'Ecologie et d'Ecotoxicologie, Faculté des Sciences, Université de Lomé, 01 B.P. 1515, Lomé 01, Togo
| | - Rabila Bamogo
- Institut de Recherche en Sciences de la Santé/Centre Muraz, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso
| | - Kelly Lionelle Ngaffo
- Institut de Recherche en Sciences de la Santé/Centre Muraz, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso.,Centre d'Excellence Africaine d'Innovation biotechnologique pour l'Elimination des Maladies à Transmission Vectorielle (CEA-ITECH-MTV), Université Nazi Boni, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso
| | - Samina Maiga
- Institut de Recherche en Sciences de la Santé/Centre Muraz, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso
| | - Rachid T Atcha-Oubou
- Programme National de Lutte contre le Paludisme/Ministère de la Santé, 01 B.P. 518, Lomé 01, Togo
| | - Ameyo M Dorkenoo
- Faculté des Sciences de la Santé, Université de Lomé, 01 B.P. 1515, Lomé 01, Togo
| | - Lucrecia Vizcaino
- Center for Global Health, Division of Parasitic Diseases and Malaria/Entomology Branch, Centers for Disease Control and Prevention (CDC), Atlanta, GA, 30329, USA
| | - Audrey Lenhart
- Center for Global Health, Division of Parasitic Diseases and Malaria/Entomology Branch, Centers for Disease Control and Prevention (CDC), Atlanta, GA, 30329, USA
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé/Centre Muraz, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso.,Centre d'Excellence Africaine d'Innovation biotechnologique pour l'Elimination des Maladies à Transmission Vectorielle (CEA-ITECH-MTV), Université Nazi Boni, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso
| | - Roch Kounbobr Dabiré
- Institut de Recherche en Sciences de la Santé/Centre Muraz, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso.,Centre d'Excellence Africaine d'Innovation biotechnologique pour l'Elimination des Maladies à Transmission Vectorielle (CEA-ITECH-MTV), Université Nazi Boni, 01 B.P. 545 , Bobo‑Dioulasso 01, Burkina Faso
| | - Guillaume Koffivi Ketoh
- Laboratoire d'Ecologie et d'Ecotoxicologie, Faculté des Sciences, Université de Lomé, 01 B.P. 1515, Lomé 01, Togo
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7
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Yaro AS, Linton YM, Dao A, Diallo M, Sanogo ZL, Samake D, Ousmane Y, Kouam C, Krajacich BJ, Faiman R, Bamou R, Woo J, Chapman JW, Reynolds DR, Lehmann T. Diversity, composition, altitude, and seasonality of high-altitude windborne migrating mosquitoes in the Sahel: Implications for disease transmission. FRONTIERS IN EPIDEMIOLOGY 2022; 2:1001782. [PMID: 38455321 PMCID: PMC10910920 DOI: 10.3389/fepid.2022.1001782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/16/2022] [Indexed: 03/09/2024]
Abstract
Recent studies have reported Anopheles mosquitoes captured at high-altitude (40-290 m above ground) in the Sahel. Here, we describe this migration modality across genera and species of African Culicidae and examine its implications for disease transmission and control. As well as Anopheles, six other genera-Culex, Aedes, Mansonia, Mimomyia, Lutzia, and Eretmapodites comprised 90% of the 2,340 mosquitoes captured at altitude. Of the 50 molecularly confirmed species (N = 2,107), 33 species represented by multiple specimens were conservatively considered high-altitude windborne migrants, suggesting it is a common migration modality in mosquitoes (31-47% of the known species in Mali), and especially in Culex (45-59%). Overall species abundance varied between 2 and 710 specimens/species (in Ae. vittatus and Cx. perexiguus, respectively). At altitude, females outnumbered males 6:1, and 93% of the females have taken at least one blood meal on a vertebrate host prior to their departure. Most taxa were more common at higher sampling altitudes, indicating that total abundance and diversity are underestimated. High-altitude flight activity was concentrated between June and November coinciding with availability of surface waters and peak disease transmission by mosquitoes. These hallmarks of windborne mosquito migration bolster their role as carriers of mosquito-borne pathogens (MBPs). Screening 921 mosquitoes using pan-Plasmodium assays revealed that thoracic infection rate in these high-altitude migrants was 2.4%, providing a proof of concept that vertebrate pathogens are transported by windborne mosquitoes at altitude. Fourteen of the 33 windborne mosquito species had been reported as vectors to 25 MBPs in West Africa, which represent 32% of the MBPs known in that region and include those that inflict the heaviest burden on human and animal health, such as malaria, yellow fever, dengue, and Rift Valley fever. We highlight five arboviruses that are most likely affected by windborne mosquitoes in West Africa: Rift Valley fever, O'nyong'nyong, Ngari, Pangola, and Ndumu. We conclude that the study of windborne spread of diseases by migrating insects and the development of surveillance to map the sources, routes, and destinations of vectors and pathogens is key to understand, predict, and mitigate existing and new threats of public health.
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Affiliation(s)
- Alpha Seydou Yaro
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Yvonne-Marie Linton
- Walter Reed Biosystematics Unit, Smithsonian Institution Museum Support Center, Suitland, MD, United States
- Department of Entomology, Smithsonian Institution, National Museum of Natural History, Washington, DC, United States
- One Health Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Adama Dao
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Moussa Diallo
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Zana L. Sanogo
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Djibril Samake
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Yossi Ousmane
- Malaria Research and Training Center (MRTC), Faculty of Medicine, Pharmacy and Odonto-Stomatology, Bamako, Mali
| | - Cedric Kouam
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
| | | | - Roy Faiman
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
| | - Roland Bamou
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
| | - Joshua Woo
- Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD, United States
| | - Jason W. Chapman
- Centre for Ecology and Conservation, and Environment and Sustainability Institute, University of Exeter, Penryn, United Kingdom
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Don R. Reynolds
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
- Rothamsted Research, Harpenden, United Kingdom
| | - Tovi Lehmann
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, United States
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8
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Perfect association between spatial swarm segregation and the X-chromosome speciation island in hybridizing Anopheles coluzzii and Anopheles gambiae populations. Sci Rep 2022; 12:10800. [PMID: 35750745 PMCID: PMC9232630 DOI: 10.1038/s41598-022-14865-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/14/2022] [Indexed: 11/08/2022] Open
Abstract
The sibling species An. coluzzii and An. gambiae s.s. are major malaria vectors thought to be undergoing sympatric speciation with gene flow. In the absence of intrinsic post-zygotic isolation between the two taxa, speciation is thought possible through the association of assortative mating and genomic regions protected from gene flow by recombination suppression. Such genomic islands of speciation have been described in pericentromeric regions of the X, 2L and 3L chromosomes. Spatial swarm segregation plays a major role in assortative mating between sympatric populations of the two species and, given their importance for speciation, genes responsible for such pre-mating reproductive barriers are expected to be protected within divergence islands. In this study 2063 male and 266 female An. coluzzii and An. gambiae s.s. individuals from natural swarms in Burkina Faso, West Africa were sampled. These were genotyped at 16 speciation island SNPs, and characterized as non-hybrid individuals, F1 hybrids or recombinant F1+n backcrossed individuals. Their genotypes at each speciation island were associated with their participation in An. coluzzii and An. gambiae-like swarms. Despite extensive introgression between the two species, the X-island genotype of non-hybrid individuals (37.6%), F1 hybrids (0.1%) and F1+n recombinants (62.3%) of either sex perfectly associated to each swarm type. Associations between swarm type and the 3L and 2L speciation islands were weakened or broken down by introgression. The functional demonstration of a close association between spatial segregation behaviour and the X speciation island lends further support to sympatric speciation models facilitated by pericentric recombination suppression in this important species complex.
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Beeton NJ, Wilkins A, Ickowicz A, Hayes KR, Hosack GR. Spatial modelling for population replacement of mosquito vectors at continental scale. PLoS Comput Biol 2022; 18:e1009526. [PMID: 35648783 PMCID: PMC9191746 DOI: 10.1371/journal.pcbi.1009526] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 06/13/2022] [Accepted: 04/22/2022] [Indexed: 11/24/2022] Open
Abstract
Malaria is one of the deadliest vector-borne diseases in the world. Researchers are developing new genetic and conventional vector control strategies to attempt to limit its burden. Novel control strategies require detailed safety assessment to ensure responsible and successful deployments. Anopheles gambiae sensu stricto (s.s.) and Anopheles coluzzii, two closely related subspecies within the species complex Anopheles gambiae sensu lato (s.l.), are among the dominant malaria vectors in sub-Saharan Africa. These two subspecies readily hybridise and compete in the wild and are also known to have distinct niches, each with spatially and temporally varying carrying capacities driven by precipitation and land use factors. We model the spread and persistence of a population-modifying gene drive system in these subspecies across sub-Saharan Africa by simulating introductions of genetically modified mosquitoes across the African mainland and its offshore islands. We explore transmission of the gene drive between the two subspecies that arise from different hybridisation mechanisms, the effects of both local dispersal and potential wind-aided migration to the spread, and the development of resistance to the gene drive. Given the best current available knowledge on the subspecies’ life histories, we find that an introduced gene drive system with typical characteristics can plausibly spread from even distant offshore islands to the African mainland with the aid of wind-driven migration, with resistance beginning to take over within a decade. Our model accounts for regional to continental scale mechanisms, and demonstrates a range of realistic dynamics including the effect of prevailing wind on spread and spatio-temporally varying carrying capacities for subspecies. As a result, it is well-placed to answer future questions relating to mosquito gene drives as important life history parameters become better understood. Conventional control methods have dramatically reduced malaria, but it still kills over 300,000 children in Africa each year, and this number could increase as their effectiveness wanes. Novel control methods using gene drives rapidly reduce or modify malaria vector populations in laboratory settings, and hence are now being considered for field applications. We use modelling to assess how a gene drive might spread and persist in the malaria-carrying subspecies Anopheles gambiae sensu stricto (s.s.) and Anopheles coluzzii. These two subspecies interbreed and compete, so we model how these interactions affect the spread of the drive at a continental scale. In scenarios that allow mosquitoes to travel on prevailing wind currents, we find that a gene drive can potentially spread across national borders—and jump from offshore islands to the African mainland—but spread is eventually arrested when the drive allele is ousted by a resistant allele. As we learn more about the population dynamics of both genetically modified and wild mosquitoes, and as gene drive systems are further developed to allow local containment and evade resistance, our model will be able to answer more detailed questions about how they can be applied in the field effectively and safely.
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Affiliation(s)
- Nicholas J. Beeton
- Data61, CSIRO, 3 Castray Esplanade, Battery Point TAS, Australia
- * E-mail: (NJB); (AW)
| | - Andrew Wilkins
- Mineral Resources, CSIRO, 1 Technology Court, Pullenvale QLD, Australia
- * E-mail: (NJB); (AW)
| | - Adrien Ickowicz
- Data61, CSIRO, 3 Castray Esplanade, Battery Point TAS, Australia
| | - Keith R. Hayes
- Data61, CSIRO, 3 Castray Esplanade, Battery Point TAS, Australia
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10
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Sougué E, Dabiré RK, Roux O. Larval habitat selection by females of two malaria vectors in response to predation risk. Acta Trop 2021; 221:106016. [PMID: 34157290 DOI: 10.1016/j.actatropica.2021.106016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/15/2021] [Accepted: 06/15/2021] [Indexed: 11/17/2022]
Abstract
For species lacking parental care, selection of a suitable habitat for their offspring, with a limited predation risk, is important. The ability of two African malaria mosquito females to detect a predation threat for their larvae was assessed through an oviposition choice test design. Our results suggest that gravid females of both Anopheles gambiae s.s. and An. coluzzii (Diptera, Culicidae) were able to detect the presence of a predator (Anisops jaczewskii, Notonectidae, Hemiptera; backswimmer). However, An. coluzzii were more likely to choose the cups containing predation cues while An. gambiae tended to avoid them for oviposition. Anopheles coluzzii females might use either alarm cues or pre-digestive cues from the external prey digestion to gauge the threat level, while An. gambiae females might use predator cues (odor or vibrations) or digestive cues from the predator. Compared to An. gambiae, An. coluzzii females seemed to accept the predation threat for their larvae to some extent. These results are consistent with the observed larval distribution in the field. Anopheles coluzzii larvae are found in complex permanent reservoirs in which the predation pressure is high, while An. gambiae larvae are more frequently found in temporary reservoirs with a lower predation threat. To our knowledge, this is the first time such a divergence in oviposition strategies regarding predation risk management by females is shown between closely related mosquito species.
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Affiliation(s)
- Emmanuel Sougué
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Roch K Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Olivier Roux
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso; MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France.
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11
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Taconet P, Porciani A, Soma DD, Mouline K, Simard F, Koffi AA, Pennetier C, Dabiré RK, Mangeas M, Moiroux N. Data-driven and interpretable machine-learning modeling to explore the fine-scale environmental determinants of malaria vectors biting rates in rural Burkina Faso. Parasit Vectors 2021; 14:345. [PMID: 34187546 PMCID: PMC8243492 DOI: 10.1186/s13071-021-04851-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/12/2021] [Indexed: 12/02/2022] Open
Abstract
Background Improving the knowledge and understanding of the environmental determinants of malaria vector abundance at fine spatiotemporal scales is essential to design locally tailored vector control intervention. This work is aimed at exploring the environmental tenets of human-biting activity in the main malaria vectors (Anopheles gambiae s.s., Anopheles coluzzii and Anopheles funestus) in the health district of Diébougou, rural Burkina Faso. Methods Anopheles human-biting activity was monitored in 27 villages during 15 months (in 2017–2018), and environmental variables (meteorological and landscape) were extracted from high-resolution satellite imagery. A two-step data-driven modeling study was then carried out. Correlation coefficients between the biting rates of each vector species and the environmental variables taken at various temporal lags and spatial distances from the biting events were first calculated. Then, multivariate machine-learning models were generated and interpreted to (i) pinpoint primary and secondary environmental drivers of variation in the biting rates of each species and (ii) identify complex associations between the environmental conditions and the biting rates. Results Meteorological and landscape variables were often significantly correlated with the vectors’ biting rates. Many nonlinear associations and thresholds were unveiled by the multivariate models, for both meteorological and landscape variables. From these results, several aspects of the bio-ecology of the main malaria vectors were identified or hypothesized for the Diébougou area, including breeding site typologies, development and survival rates in relation to weather, flight ranges from breeding sites and dispersal related to landscape openness. Conclusions Using high-resolution data in an interpretable machine-learning modeling framework proved to be an efficient way to enhance the knowledge of the complex links between the environment and the malaria vectors at a local scale. More broadly, the emerging field of interpretable machine learning has significant potential to help improve our understanding of the complex processes leading to malaria transmission, and to aid in developing operational tools to support the fight against the disease (e.g. vector control intervention plans, seasonal maps of predicted biting rates, early warning systems). Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04851-x.
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Affiliation(s)
- Paul Taconet
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France. .,Institut de Recherche en Sciences de La Santé (IRSS), Bobo-Dioulasso, Burkina Faso.
| | | | - Dieudonné Diloma Soma
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France.,Institut de Recherche en Sciences de La Santé (IRSS), Bobo-Dioulasso, Burkina Faso.,Université Nazi Boni, Bobo-Dioulasso, Burkina Faso
| | - Karine Mouline
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Frédéric Simard
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | | | - Cedric Pennetier
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France.,Institut de Recherche en Sciences de La Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Roch Kounbobr Dabiré
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Morgan Mangeas
- ESPACE-DEV, Université Montpellier, IRD, Université Antilles, Université Guyane, Université Réunion, Montpellier, France
| | - Nicolas Moiroux
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France.,Institut de Recherche en Sciences de La Santé (IRSS), Bobo-Dioulasso, Burkina Faso
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12
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Yovogan B, Sovi A, Padonou GG, Adoha CJ, Akinro B, Chitou S, Accrombessi M, Dangbénon E, Akpovi H, Messenger LA, Ossè R, Hounto AO, Cook J, Kleinschmidt I, Ngufor C, Rowland M, Protopopoff N, Akogbéto MC. Pre-intervention characteristics of the mosquito species in Benin in preparation for a randomized controlled trial assessing the efficacy of dual active-ingredient long-lasting insecticidal nets for controlling insecticide-resistant malaria vectors. PLoS One 2021; 16:e0251742. [PMID: 34014982 PMCID: PMC8136630 DOI: 10.1371/journal.pone.0251742] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/01/2021] [Indexed: 11/18/2022] Open
Abstract
Background This study provides detailed characteristics of vector populations in preparation for a three-arm cluster randomized controlled trial (RCT) aiming to compare the community impact of dual active-ingredient (AI) long-lasting insecticidal nets (LLINs) that combine two novel insecticide classes–chlorfenapyr or pyriproxifen–with alpha-cypermethrin to improve the prevention of malaria transmitted by insecticide-resistant vectors compared to standard pyrethroid LLINs. Methods The study was carried out in 60 villages across Cove, Zangnanando and Ouinhi districts, southern Benin. Mosquito collections were performed using human landing catches (HLCs). After morphological identification, a sub-sample of Anopheles gambiae s.l. were dissected for parity, analyzed by PCR for species and presence of L1014F kdr mutation and by ELISA-CSP to identify Plasmodium falciparum sporozoite infection. WHO susceptibility tube tests were performed by exposing adult An. gambiae s.l., collected as larvae from each district, to 0.05% alphacypermethrin, 0.75% permethrin, 0.1% bendiocarb and 0.25% pirimiphos-methyl. Synergist assays were also conducted with exposure first to 4% PBO followed by alpha-cypermethrin. Results An. gambiae s.l. (n = 10807) was the main malaria vector complex found followed by Anopheles funestus s.l. (n = 397) and Anopheles nili (n = 82). An. gambiae s.l. was comprised of An. coluzzii (53.9%) and An. gambiae s.s. (46.1%), both displaying a frequency of the L1014F kdr mutation >80%. Although more than 80% of people slept under standard LLIN, human biting rate (HBR) in An. gambiae s.l. was higher indoors [26.5 bite/person/night (95% CI: 25.2–27.9)] than outdoors [18.5 b/p/n (95% CI: 17.4–19.6)], as were the trends for sporozoite rate (SR) [2.9% (95% CI: 1.7–4.8) vs 1.8% (95% CI: 0.6–3.8)] and entomological inoculation rate (EIR) [21.6 infected bites/person/month (95% CI: 20.4–22.8) vs 5.4 (95% CI: 4.8–6.0)]. Parous rate was 81.6% (95%CI: 75.4–88.4). An. gambiae s.l. was resistant to alpha-cypermethrin and permethrin but, fully susceptible to bendiocarb and pirimiphos-methyl. PBO pre-exposure followed by alpha-cypermethrin treatment induced a higher 24 hours mortality compared to alphacypermethrin alone but not exceeding 40%. Conclusions Despite a high usage of standard pyrethroid LLINs, the study area is characterized by intense malaria transmission. The main vectors An. coluzzii and An. gambiae s.s. were both highly resistant to pyrethroids and displayed multiple resistance mechanisms, L1014F kdr mutation and mixed function oxidases. These conditions of the study area make it an appropriate site to conduct the trial that aims to assess the effect of novel dual-AI LLINs on malaria transmitted by insecticide-resistant vectors.
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Affiliation(s)
- Boulais Yovogan
- Faculté des Sciences et Techniques de l’Université d’Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Arthur Sovi
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculté d’Agronomie, Université de Parakou, Parakou, Benin
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Gil G. Padonou
- Faculté des Sciences et Techniques de l’Université d’Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Constantin J. Adoha
- Faculté des Sciences et Techniques de l’Université d’Abomey-Calavi, Abomey-Calavi, Benin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Bruno Akinro
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Saïd Chitou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Manfred Accrombessi
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Benin
| | | | - Hilaire Akpovi
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Louisa A. Messenger
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- American Society for Microbiology, Washington, DC, United States of America
| | - Razaki Ossè
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Ecole de Gestion et d’Exploitation des Systèmes d’Elevage, Université Nationale d’Agriculture, Kétou, Benin
| | - Aurore Ogouyemi Hounto
- Programme Nationale de Lutte Contre Le Paludisme (PNLP), Cotonou, Benin
- Faculté des Sciences de la Santé, Université d’Abomey-Calavi, Cotonou, Benin
| | - Jackie Cook
- Medical Research Council (MRC) Tropical International Statistics and Epidemiology Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Immo Kleinschmidt
- Medical Research Council (MRC) Tropical International Statistics and Epidemiology Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
- School of Pathology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
- Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Corine Ngufor
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Mark Rowland
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Natacha Protopopoff
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Roux O, Renault D, Mouline K, Diabaté A, Simard F. Living with predators at the larval stage has differential long-lasting effects on adult life history and physiological traits in two anopheline mosquito species. JOURNAL OF INSECT PHYSIOLOGY 2021; 131:104234. [PMID: 33831434 DOI: 10.1016/j.jinsphys.2021.104234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 03/25/2021] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Olivier Roux
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France; Institut de Recherche des Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso.
| | - David Renault
- Univ Rennes, CNRS, ECOBIO (Ecosystèmes biodiversitéévolution) - UMR 6553, F-35000 Rennes, France; Institut Universitaire de France, 1 Rue Descartes, 75231 Paris Cedex 05, France
| | - Karine Mouline
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France; Institut de Recherche des Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Abdoulaye Diabaté
- Institut de Recherche des Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
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14
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Connolly JB, Mumford JD, Fuchs S, Turner G, Beech C, North AR, Burt A. Systematic identification of plausible pathways to potential harm via problem formulation for investigational releases of a population suppression gene drive to control the human malaria vector Anopheles gambiae in West Africa. Malar J 2021; 20:170. [PMID: 33781254 PMCID: PMC8006393 DOI: 10.1186/s12936-021-03674-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Population suppression gene drive has been proposed as a strategy for malaria vector control. A CRISPR-Cas9-based transgene homing at the doublesex locus (dsxFCRISPRh) has recently been shown to increase rapidly in frequency in, and suppress, caged laboratory populations of the malaria mosquito vector Anopheles gambiae. Here, problem formulation, an initial step in environmental risk assessment (ERA), was performed for simulated field releases of the dsxFCRISPRh transgene in West Africa. METHODS Building on consultative workshops in Africa that previously identified relevant environmental and health protection goals for ERA of gene drive in malaria vector control, 8 potentially harmful effects from these simulated releases were identified. These were stratified into 46 plausible pathways describing the causal chain of events that would be required for potential harms to occur. Risk hypotheses to interrogate critical steps in each pathway, and an analysis plan involving experiments, modelling and literature review to test each of those risk hypotheses, were developed. RESULTS Most potential harms involved increased human (n = 13) or animal (n = 13) disease transmission, emphasizing the importance to subsequent stages of ERA of data on vectorial capacity comparing transgenics to non-transgenics. Although some of the pathways (n = 14) were based on known anatomical alterations in dsxFCRISPRh homozygotes, many could also be applicable to field releases of a range of other transgenic strains of mosquito (n = 18). In addition to population suppression of target organisms being an accepted outcome for existing vector control programmes, these investigations also revealed that the efficacy of population suppression caused by the dsxFCRISPRh transgene should itself directly affect most pathways (n = 35). CONCLUSIONS Modelling will play an essential role in subsequent stages of ERA by clarifying the dynamics of this relationship between population suppression and reduction in exposure to specific potential harms. This analysis represents a comprehensive identification of plausible pathways to potential harm using problem formulation for a specific gene drive transgene and organism, and a transparent communication tool that could inform future regulatory studies, guide subsequent stages of ERA, and stimulate further, broader engagement on the use of population suppression gene drive to control malaria vectors in West Africa.
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Affiliation(s)
- John B Connolly
- Department of Life Sciences, Imperial College London, London, UK.
| | - John D Mumford
- Centre for Environmental Policy, Imperial College London, London, UK
| | - Silke Fuchs
- Department of Life Sciences, Imperial College London, London, UK
| | - Geoff Turner
- Department of Life Sciences, Imperial College London, London, UK
| | | | - Ace R North
- Department of Zoology, University of Oxford, Oxford, UK
| | - Austin Burt
- Department of Life Sciences, Imperial College London, London, UK
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15
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Akpodiete NO, Tripet F. Laboratory and microcosm experiments reveal contrasted adaptive responses to ammonia and water mineralisation in aquatic stages of the sibling species Anopheles gambiae (sensu stricto) and Anopheles coluzzii. Parasit Vectors 2021; 14:17. [PMID: 33407790 PMCID: PMC7789177 DOI: 10.1186/s13071-020-04483-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/12/2020] [Indexed: 11/10/2022] Open
Abstract
Background The sibling species of the malaria mosquito, Anopheles gambiae (sensu stricto) and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype-by-Environment (G × E) interactions, have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields, which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae (s.s.) Methods To highlight G × E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across two contrasted microcosms to highlight G × E interactions under conditions such as those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae (s.s.) strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae (s.s.), and vice versa, in the rain puddle environment. Conclusions Evidence for such G × E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice fields in An. coluzzii may have been an important driver of its ecological speciation. ![]()
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Affiliation(s)
- Nwamaka Oluchukwu Akpodiete
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, UK
| | - Frédéric Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, UK.
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16
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Foley DH, Wilkerson RC, Kim HC, Klein TA, Kim MS, Li C, Levin DM, Rueda LM. Wing size and parity as markers of cohort demography for potential Anopheles (Culicidae: Diptera) malaria vectors in the Republic of Korea. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2020; 45:366-379. [PMID: 33207064 DOI: 10.1111/jvec.12406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
Wing lengths of parous (P) and nulliparous (NP) PCR-identified female Anopheles belenrae, An. kleini, An. pullus, and An. sinensis were determined from weekly trap collections at Camp Humphreys (CH), Ganghwa Island (GH), and Warrior Base (WB), Republic of Korea (ROK) during Jun-Oct, 2009. Wing length was greatest at the beginning and end of the study period. Wing length of NPs tended to be less than that of Ps before the period of maximum greening (Jul-Aug) but greater thereafter. Larger specimens tended to be Ps, and weekly wing length of Ps appeared less variable than NPs, possibly due to selection. A bimodal wing length frequency distribution of An. sinensis suggested two forms comprising small- (≤4.5 mm, SW) and large-winged females (>4.5 mm, LW). LW comprised the majority of peaks in abundance, however %SW, while still a minority, often increased during these times suggesting a density-dependent effect. At WB and GH, a two to three-week periodicity in %SW was obvious for An. sinensis and An. kleini. Analyses of weather station and satellite data showed that smaller-winged An. sinensis were associated with warmer, more humid, and greener times of the year. SW and LW specimens possibly result from agricultural practices that are common across large areas; regular synchronous peaks of SW and LW were observed from different sites. Peaks in SW Ps followed peaks in NPs in a 'ripple effect' one to two weeks apart, suggesting that wing length combined with parity could be used to follow the emergence and survival of mosquito cohorts.
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Affiliation(s)
- Desmond H Foley
- Walter Reed Biosystematics Unit, Department of Entomology, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, U.S.A
- Entomology Department, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20013, U.S.A
| | - Richard C Wilkerson
- Walter Reed Biosystematics Unit, Department of Entomology, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, U.S.A
- Entomology Department, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20013, U.S.A
| | - Heung Chul Kim
- Force Health Protection and Preventive Medicine, US Army Medical Activity-Korea, 65th Medical Brigade, Unit #15281, APO AP 96271-5281
| | - Terry A Klein
- Force Health Protection and Preventive Medicine, US Army Medical Activity-Korea, 65th Medical Brigade, Unit #15281, APO AP 96271-5281
| | - Myung-Soon Kim
- Force Health Protection and Preventive Medicine, US Army Medical Activity-Korea, 65th Medical Brigade, Unit #15281, APO AP 96271-5281
| | - Cong Li
- Walter Reed Biosystematics Unit, Department of Entomology, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, U.S.A
| | - David M Levin
- Walter Reed Biosystematics Unit, Department of Entomology, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, U.S.A
| | - Leopoldo M Rueda
- Walter Reed Biosystematics Unit, Department of Entomology, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, U.S.A
- Entomology Department, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20013, U.S.A
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17
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Niang A, Sawadogo SP, Dabiré RK, Tripet F, Diabaté A. Assessment of the ecologically dependent post-zygotic isolation between Anopheles coluzzii and Anopheles gambiae. PLoS One 2020; 15:e0240625. [PMID: 33119635 PMCID: PMC7595400 DOI: 10.1371/journal.pone.0240625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/29/2020] [Indexed: 11/26/2022] Open
Abstract
Within the Anopheles gambiae complex, the sibling species An. coluzzii and An. gambiae are undergoing sympatric speciation. These species are characterized by rare hybrids in most of their geographical distribution. A strong assortative mating mediated by spatial swarm segregation has been shown whereas no intrinsic post-zygotic barriers have been found in laboratory conditions. To test the role of the hybridisation in reproductive isolation in natural populations transplant experiment are therefore needed to establish the significance of post-zygotic barriers. Previous studies indicated that predation is one of the major forces driving ecological divergence between An. gambiae and An. coluzzii. Here we extended these studies to their hybrids. Parental species and their F1 hybrids from reciprocal crosses were generated by the forced-mating technique as follows: female An. coluzzii × male An. coluzzii; female An. coluzzii × male An. gambiae; female An. gambiae × male An. coluzzii and female An. gambiae × Male An. gambiae. First instar larvae of each group from the crossing (here after An. coluzzii, Hybrid COL/GAM, Hybrid GAM/COL and An. gambiae, respectively) were transplanted in a field experiment with predation effect. Emergence success, development time of larvae and body size of the newly emerging adults were estimated as fitness components and then compared between parental species and F1 hybrids in absence and in presence of predators. Our findings confirm that An. coluzzii had higher fitness than An. gambiae in presence of predators versus in absence of predators. Moreover, the fitness of the F1 hybrid COL/GAM whose female parent was An. coluzzii matched that of An. coluzzii while that of the F1 reciprocal hybrid GAM/COL was similar to An. gambiae.
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Affiliation(s)
- Abdoulaye Niang
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | | | - Roch K. Dabiré
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Frederic Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
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18
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Soma DD, Zogo BM, Somé A, Tchiekoi BN, Hien DFDS, Pooda HS, Coulibaly S, Gnambani JE, Ouari A, Mouline K, Dahounto A, Ouédraogo GA, Fournet F, Koffi AA, Pennetier C, Moiroux N, Dabiré RK. Anopheles bionomics, insecticide resistance and malaria transmission in southwest Burkina Faso: A pre-intervention study. PLoS One 2020; 15:e0236920. [PMID: 32745085 PMCID: PMC7398507 DOI: 10.1371/journal.pone.0236920] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/17/2020] [Indexed: 11/21/2022] Open
Abstract
Background Twenty-seven villages were selected in southwest Burkina Faso to implement new vector control strategies in addition to long lasting insecticidal nets (LLINs) through a Randomized Controlled Trial (RCT). We conducted entomological surveys in the villages during the dry cold season (January 2017), dry hot season (March 2017) and rainy season (June 2017) to describe malaria vectors bionomics, insecticide resistance and transmission prior to this trial. Methods We carried out hourly catches (from 17:00 to 09:00) inside and outside 4 houses in each village using the Human Landing Catch technique. Mosquitoes were identified using morphological taxonomic keys. Specimens belonging to the Anopheles gambiae complex and Anopheles funestus group were identified using molecular techniques as well as detection of Plasmodium falciparum infection and insecticide resistance target-site mutations. Results Eight Anopheles species were detected in the area. Anopheles funestus s.s was the main vector during the dry cold season. It was replaced by Anopheles coluzzii during the dry hot season whereas An. coluzzii and An. gambiae s.s. were the dominant species during the rainy season. Species composition of the Anopheles population varied significantly among seasons. All insecticide resistance mechanisms (kdr-w, kdr-e and ace-1 target site mutations) investigated were found in each members of the An. gambiae complex but at different frequencies. We observed early and late biting phenotypes in the main malaria vector species. Entomological inoculation rates were 2.61, 2.67 and 11.25 infected bites per human per month during dry cold season, dry hot season and rainy season, respectively. Conclusion The entomological indicators of malaria transmission were high despite the universal coverage with LLINs. We detected early and late biting phenotypes in the main malaria vector species as well as physiological insecticide resistance mechanisms. These data will be used to evaluate the impact of complementary tools to LLINs in an upcoming RCT.
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Affiliation(s)
- Dieudonné Diloma Soma
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
- Université Nazi Boni, Bobo-Dioulasso, Burkina Faso
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
- * E-mail:
| | - Barnabas Mahugnon Zogo
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
- Institut Pierre Richet (IPR), Bouaké, Côte d’Ivoire
- Université d’Abomey Calavi, Abomey-Calavi, Benin
| | - Anthony Somé
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Bertin N’Cho Tchiekoi
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
- Institut Pierre Richet (IPR), Bouaké, Côte d’Ivoire
| | | | - Hermann Sié Pooda
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
- Université de Dédougou, Dédougou, Burkina Faso
| | - Sanata Coulibaly
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | | | - Ali Ouari
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Karine Mouline
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Amal Dahounto
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | | | - Florence Fournet
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | | | - Cédric Pennetier
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
- Institut Pierre Richet (IPR), Bouaké, Côte d’Ivoire
| | - Nicolas Moiroux
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Roch Kounbobr Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
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19
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Roux O, Robert V. Larval predation in malaria vectors and its potential implication in malaria transmission: an overlooked ecosystem service? Parasit Vectors 2019; 12:217. [PMID: 31068213 PMCID: PMC6505304 DOI: 10.1186/s13071-019-3479-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/03/2019] [Indexed: 01/13/2023] Open
Abstract
The role of aquatic predators in controlling the anopheline aquatic stage has been known for decades. Recently, studies have highlighted that exposition to predation stress during aquatic development can have a profound impact on life-history traits (e.g. growth rate, fecundity and longevity) and consequently on the ability of adults to transmit human malaria parasites. In this study, we present a review aiming to contextualize the role of Anopheles larvae predators as an ecosystem factor interacting with the malaria pathogen through its vector, i.e. the female adult Anopheles. We first envisage the predator diversity that anopheline vectors are susceptible to encounter in their aquatic habitats. We then focus on mosquito-predator interactions with a special mention to anti-predator behaviors and prey adaptations developed to deal with the predation threat. Next, we address the direct and indirect effects of larval predation stress on mosquito populations and on individual life-history traits, which strongly suggest some carry-over effect of the impact of larval predation on vectorial capacity. The last part addresses the impact of human activities on larval predation. Concluding remarks highlight gaps in the knowledge of anopheline bio-ecology which may constitute avenues for researchers in the future.
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Affiliation(s)
- Olivier Roux
- MIVEGEC Unit, IRD-CNRS, Université de Montpellier, Montpellier, France. .,Institut de Recherche des Sciences de la Santé (IRSS), 01 BP 545, Bobo-Dioulasso 01, Burkina Faso.
| | - Vincent Robert
- MIVEGEC Unit, IRD-CNRS, Université de Montpellier, Montpellier, France
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20
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Krol L, Gorsich EE, Hunting ER, Govender D, van Bodegom PM, Schrama M. Eutrophication governs predator-prey interactions and temperature effects in Aedes aegypti populations. Parasit Vectors 2019; 12:179. [PMID: 31014388 PMCID: PMC6480876 DOI: 10.1186/s13071-019-3431-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 04/04/2019] [Indexed: 12/04/2022] Open
Abstract
Background Mosquito population dynamics are driven by large-scale (e.g. climatological) and small-scale (e.g. ecological) factors. While these factors are known to independently influence mosquito populations, it remains uncertain how drivers that simultaneously operate under natural conditions interact to influence mosquito populations. We, therefore, developed a well-controlled outdoor experiment to assess the interactive effects of two ecological drivers, predation and nutrient availability, on mosquito life history traits under multiple temperature regimes. Methods We conducted a temperature-controlled mesocosm experiment in Kruger National Park, South Africa, with the yellow fever mosquito, Aedes aegypti. We investigated how larval survival, emergence and development rates were impacted by the presence of a locally-common invertebrate predator (backswimmers Anisops varia Fieber (Notonectidae: Hemiptera), nutrient availability (oligotrophic vs eutrophic, reflecting field conditions), water temperature, and interactions between each driver. Results We observed that the effects of predation and temperature both depended on eutrophication. Predation caused lower adult emergence in oligotrophic conditions but higher emergence under eutrophic conditions. Higher temperatures caused faster larval development rates in eutrophic but not oligotrophic conditions. Conclusions Our study shows that ecological bottom-up and top-down drivers strongly and interactively govern mosquito life history traits for Ae. aegypti populations. Specifically, we show that eutrophication can inversely affect predator–prey interactions and mediate the effect of temperature on mosquito survival and development rates. Hence, our results suggest that nutrient pollution can overrule biological constraints on natural mosquito populations and highlights the importance of studying multiple factors. Electronic supplementary material The online version of this article (10.1186/s13071-019-3431-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Louie Krol
- Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands.,Naturalis Biodiversity Centre, Leiden, The Netherlands
| | - Erin E Gorsich
- The Zeeman Institute for Systems Biology & Infectious Disease Epidemiology Research, University of Warwick, Coventry, UK.,School of Life Sciences, University of Warwick, Coventry, UK
| | - Ellard R Hunting
- School of Biological Sciences, University of Bristol, Bristol, UK.,Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Danny Govender
- Department of Paraclinical Sciences, University of Pretoria, Pretoria, South Africa.,Scientific Services Kruger National Park, Skukuza, South Africa
| | - Peter M van Bodegom
- Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands
| | - Maarten Schrama
- Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands. .,Naturalis Biodiversity Centre, Leiden, The Netherlands.
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21
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Salako AS, Ossè R, Padonou GG, Dagnon F, Aïkpon R, Kpanou C, Sagbohan H, Sovi A, Sèzonlin M, Akogbeto MC. Population Dynamics of Anopheles gambiae s.l. and Culex quinquefasciatus in Rural and Urban Settings Before an Indoor Residual Spraying Campaign in Northern Benin. Vector Borne Zoonotic Dis 2019; 19:674-684. [PMID: 30964413 DOI: 10.1089/vbz.2018.2409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: The purpose of this report is to provide information on Culicidae diversity; biting behavior and spatio-seasonal variation of abundance of Anopheles gambiae s.l. and Culex quinquefasciatus in rural and urban settings of the Alibori and Donga regions, Northern Benin, where an indoor residual spraying (IRS) campaign to control malaria is planned. Methods: Both human landing catches, associated with pyrethrum spray catches were used to monitor the mosquito populations in 12 sites with 1 urban and 1 rural located in each of the 6 districts randomly selected in the two targeted regions. After morphological identification of all mosquito specimens, biting behavior and density of An. gambiae s.l. and Cx quinquefasciatus were studied. PCR was also performed on An. gambiae s.l., to identify sibling species and its seasonal variation. Results: A total of 10,367 mosquitoes were captured, related to 14 species of the genera, Anopheles, Aedes, Culex and Mansonia. Of the total species collection, 40.39% were An. gambiae s.l. and 56.85% were Cx. quinquefasciatus. An. gambiae s.l. was more abundant in Donga (2521 specimens) compared with Alibori (1666 specimens). The opposite trend was observed with Cx. quinquefasciatus (2162 specimens in Donga against 4028 in Alibori). An. gambiae s.l. was predominant and displayed a higher blood feeding rate in rural areas, whereas Cx. quinquefasciatus was in majority in urban areas. An. gambiae s.l. was more endophagic, whereas Cx. quinquefasciatus showed similar indoor and outdoor biting behavior. An. gambiae s.l. was composed of An. coluzzii found in majority in the drought, and An. gambiae, which was predominant in the rainy season. Conclusion: The predominance of the malaria vector, An. gambiae s.l. and their higher blood feeding rate and their significantly high endophagy in rural areas indicate that these areas should be primarily targeted with the IRS operations to have a substantial impact on malaria transmission. Endophagy, characteristic of An. gambiae s.l. in our study area, suggests that IRS will have a positive impact on vector control if implemented 1 week before June that is the onset of the rainy season.
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Affiliation(s)
- Albert Sourou Salako
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin.,Department of Zoology, Faculty of Sciences and Techniques, University of Abomey Calavi, Abomey Calavi, Benin
| | - Razaki Ossè
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin.,Laboratory of Animal and Fishery Sciences, School of Management and Exploitation of Livestock Systems, National University of Agriculture, Ketou, Benin
| | - Gil G Padonou
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin.,Department of Zoology, Faculty of Sciences and Techniques, University of Abomey Calavi, Abomey Calavi, Benin
| | - Fortuné Dagnon
- U.S. President's Malaria Initiative, US Agency for International Development, Cotonou, Benin
| | - Rock Aïkpon
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin.,Biology Department, Superior Normal School, National University of Sciences, Technology, Engineering and Mathematics, Abomey, Benin
| | - Casimir Kpanou
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin.,Department of Zoology, Faculty of Sciences and Techniques, University of Abomey Calavi, Abomey Calavi, Benin
| | - Hermann Sagbohan
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin.,Department of Zoology, Faculty of Sciences and Techniques, University of Abomey Calavi, Abomey Calavi, Benin
| | - Arthur Sovi
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Michel Sèzonlin
- Department of Zoology, Faculty of Sciences and Techniques, University of Abomey Calavi, Abomey Calavi, Benin
| | - Martin C Akogbeto
- Vector Ecology Department, Center for Research in Entomology of Cotonou, Cotonou, Benin.,Department of Zoology, Faculty of Sciences and Techniques, University of Abomey Calavi, Abomey Calavi, Benin
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22
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Epopa PS, Collins CM, North A, Millogo AA, Benedict MQ, Tripet F, Diabate A. Seasonal malaria vector and transmission dynamics in western Burkina Faso. Malar J 2019; 18:113. [PMID: 30940141 PMCID: PMC6444393 DOI: 10.1186/s12936-019-2747-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/25/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the context of widespread mosquito resistance to currently available pesticides, novel, precise genetic vector control methods aimed at population suppression or trait replacement are a potentially powerful approach that could complement existing malaria elimination interventions. Such methods require knowledge of vector population composition, dynamics, behaviour and role in transmission. Here were characterized these parameters in three representative villages, Bana, Pala and Souroukoudingan, of the Sudano-Sahelian belt of Burkina Faso, a region where bed net campaigns have recently intensified. METHODS From July 2012 to November 2015, adult mosquitoes were collected monthly using pyrethroid spray catches (PSC) and human landing catches (HLC) in each village. Larval habitat prospections assessed breeding sites abundance at each site. Mosquitoes collected by PSC were identified morphologically, and then by molecular technique to species where required, to reveal the seasonal dynamics of local vectors. Monthly entomological inoculation rates (EIR) that reflect malaria transmission dynamics were estimated by combining the HLC data with mosquito sporozoite infection rates (SIR) identified through ELISA-CSP. Finally, population and EIR fluctuations were fit to locally-collected rainfall data to highlight the strong seasonal determinants of mosquito abundance and malaria transmission in this region. RESULTS The principal malaria vectors found were in the Anopheles gambiae complex. Mosquito abundance peaked during the rainy season, but there was variation in vector species composition between villages. Mean survey HLC and SIR were similar across villages and ranged from 18 to 48 mosquitoes/person/night and from 3.1 to 6.6% prevalence. The resulting monthly EIRs were extremely high during the rainy season (0.91-2.35 infectious bites/person/day) but decreased substantially in the dry season (0.03-0.22). Vector and malaria transmission dynamics generally tracked seasonal rainfall variations, and the highest mosquito abundances and EIRs occurred in the rainy season. However, despite low residual mosquito populations, mosquitoes infected with malaria parasites remained present in the dry season. CONCLUSION These results highlight the important vector control challenge facing countries with high EIR despite the recent campaigns of bed net distribution. As demonstrated in these villages, malaria transmission is sustained for large parts of the year by a very high vector abundance and high sporozoite prevalence, resulting in seasonal patterns of hyper and hypo-endemicity. There is, therefore, an urgent need for additional vector control tools that can target endo and exophillic mosquito populations.
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Affiliation(s)
- Patric Stephane Epopa
- Institut de Recherche en Sciences de la santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso.
| | | | - Ace North
- Department of Zoology, University of Oxford, Oxford, UK
| | | | | | - Frederic Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, UK
| | - Abdoulaye Diabate
- Institut de Recherche en Sciences de la santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
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23
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Mosquito microevolution drives Plasmodium falciparum dynamics. Nat Microbiol 2019; 4:941-947. [PMID: 30911126 DOI: 10.1038/s41564-019-0414-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 02/14/2019] [Indexed: 12/16/2022]
Abstract
Malaria, a major cause of child mortality in Africa, is engendered by Plasmodium parasites that are transmitted by anopheline mosquitoes. Fitness of Plasmodium parasites is closely linked to the ecology and evolution of its anopheline vector. However, whether the genetic structure of vector populations impacts malaria transmission remains unknown. Here, we describe a partitioning of the African malaria vectors into generalists and specialists that evolve along ecological boundaries. We next identify the contribution of mosquito species to Plasmodium abundance using Granger causality tests for time-series data collected over two rainy seasons in Mali. We find that mosquito microevolution, defined by changes in the genetic structure of a population over short ecological timescales, drives Plasmodium dynamics in nature, whereas vector abundance, infection prevalence, temperature and rain have low predictive values. Our study demonstrates the power of time-series approaches in vector biology and highlights the importance of focusing local vector control strategies on mosquito species that drive malaria dynamics.
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24
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Collins CM, Bonds JAS, Quinlan MM, Mumford JD. Effects of the removal or reduction in density of the malaria mosquito, Anopheles gambiae s.l., on interacting predators and competitors in local ecosystems. MEDICAL AND VETERINARY ENTOMOLOGY 2019; 33:1-15. [PMID: 30044507 PMCID: PMC6378608 DOI: 10.1111/mve.12327] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/23/2018] [Accepted: 06/15/2018] [Indexed: 05/23/2023]
Abstract
New genetic control methods for mosquitoes may reduce vector species without direct effects on other species or the physical environment common with insecticides or drainage. Effects on predators and competitors could, however, be a concern as Anopheles gambiae s.l. is preyed upon in all life stages. We overview the literature and assess the strength of the ecological interactions identified. Most predators identified consume many other insect species and there is no evidence that any species preys exclusively on any anopheline mosquito. There is one predatory species with a specialisation on blood-fed mosquitoes including An. gambiae s.l.. Evarcha culicivora is a jumping spider, known as the vampire spider, found around Lake Victoria. There is no evidence that these salticids require Anopheles mosquitoes and will readily consume blood-fed Culex. Interspecific competition studies focus on other mosquitoes of larval habitats. Many of these take place in artificial cosms and give contrasting results to semi-field studies. This may limit their extrapolation regarding the potential impact of reduced An. gambiae numbers. Previous mosquito control interventions are informative and identify competitive release and niche opportunism; so while the identity and relative abundance of the species present may change, the biomass available to predators may not.
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Affiliation(s)
- C. M. Collins
- Centre for Environmental PolicyImperial College LondonLondonU.K.
| | - J. A. S. Bonds
- Bonds Consulting Group LLCPanama City Beach, FloridaU.S.A.
| | - M. M. Quinlan
- Centre for Environmental PolicyImperial College LondonLondonU.K.
| | - J. D. Mumford
- Centre for Environmental PolicyImperial College LondonLondonU.K.
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25
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Simões PMV, Gibson G, Russell IJ. Pre-copula acoustic behaviour of males in the malarial mosquitoes Anopheles coluzzii and Anopheles gambiae s.s. does not contribute to reproductive isolation. ACTA ACUST UNITED AC 2017; 220:379-385. [PMID: 28148817 DOI: 10.1242/jeb.149757] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/09/2016] [Indexed: 11/20/2022]
Abstract
We reveal that males of two members of the Anopheles gambiae s.l. species complex, Anopheles coluzzii and Anopheles gambiae s.s. (hereafter A. gambiae), which are both malaria vectors, perform a stereotypical acoustic behaviour in response to pure tones at frequencies that encompass the frequency range of the female's flight-tones. This behaviour resembles that described for Culex quinquefasciatus and consists of phonotactic flight initiated by a steep increase in wing-beat frequency (WBF) followed by rapid frequency modulation (RFM) of WBF when in close proximity to the sound source. RFM was elicited without acoustic feedback or the presence of a live female, but it appears to be a stereotypic behaviour in the immediate lead up to copula formation. RFM is an independent and different behavioural process from harmonic convergence interactions used by male-female pairs for mate recognition at earlier stages of mating. Acoustic threshold for RFM was used to plot behavioural audiograms from free-flying A coluzzii and A gambiae males. These audiograms were almost identical (minima ∼400 Hz) and encompassed the WBF ranges of A coluzzii (378-601 Hz) and A gambiae (373-590 Hz) females, indicating that males of the two species share similar frequency tuning and range. Furthermore, no differences were found between the two species in their WBFs, RFM behaviour or harmonic convergence ratios. These results indicate that assortative mating between A coluzzii and A gambiae is unlikely to be based on male-specific acoustic behaviours during RFM. The significance of these findings in relation to possible mechanisms for assortative mating is discussed.
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Affiliation(s)
- Patrício M V Simões
- Sensory Neuroscience Research Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK
| | - Gabriella Gibson
- Department of Agriculture, Health and Environment, Natural Resources Institute, University of Greenwich, Chatham, Kent ME4 4TB, UK
| | - Ian J Russell
- Sensory Neuroscience Research Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK
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26
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Riehle MM, Bukhari T, Gneme A, Guelbeogo WM, Coulibaly B, Fofana A, Pain A, Bischoff E, Renaud F, Beavogui AH, Traore SF, Sagnon N, Vernick KD. The Anopheles gambiae 2La chromosome inversion is associated with susceptibility to Plasmodium falciparum in Africa. eLife 2017. [PMID: 28643631 PMCID: PMC5482571 DOI: 10.7554/elife.25813] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Chromosome inversions suppress genetic recombination and establish co-adapted gene complexes, or supergenes. The 2La inversion is a widespread polymorphism in the Anopheles gambiae species complex, the major African mosquito vectors of human malaria. Here we show that alleles of the 2La inversion are associated with natural malaria infection levels in wild-captured vectors from West and East Africa. Mosquitoes carrying the more-susceptible allele (2L+a) are also behaviorally less likely to be found inside houses. Vector control tools that target indoor-resting mosquitoes, such as bednets and insecticides, are currently the cornerstone of malaria control in Africa. Populations with high levels of the 2L+a allele may form reservoirs of persistent outdoor malaria transmission requiring novel measures for surveillance and control. The 2La inversion is a major and previously unappreciated component of the natural malaria transmission system in Africa, influencing both malaria susceptibility and vector behavior.
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Affiliation(s)
- Michelle M Riehle
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, United States
| | - Tullu Bukhari
- Department of Zoology, Maseno University, Maseno, Kenya
| | - Awa Gneme
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Wamdaogo M Guelbeogo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Boubacar Coulibaly
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Bamako, Mali
| | - Abdrahamane Fofana
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Bamako, Mali
| | - Adrien Pain
- Department of Parasites and Insect Vectors, Unit of Genetics and Genomics of Insect Vectors, Institut Pasteur, Paris, France.,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France.,Bioinformatics and Biostatistics Hub (C3BI), USR 3756 IP CNRS, Institut Pasteur, Paris, France
| | - Emmanuel Bischoff
- Department of Parasites and Insect Vectors, Unit of Genetics and Genomics of Insect Vectors, Institut Pasteur, Paris, France.,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France
| | - Francois Renaud
- Laboratoire Maladies Infectieuses et Vecteurs: Ecologie Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche pour le Développement (IRD), Montpellier, France.,UMR 224-5290, Centre National de la Recherche Scientifique (CNRS), Montpellier, France
| | - Abdoul H Beavogui
- Centre de Formation et de Recherche en Santé Rurale de Mafèrinyah, Conakry, Guinea
| | - Sekou F Traore
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Bamako, Mali
| | - N'Fale Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Kenneth D Vernick
- Department of Parasites and Insect Vectors, Unit of Genetics and Genomics of Insect Vectors, Institut Pasteur, Paris, France.,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France
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27
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Vicente JL, Clarkson CS, Caputo B, Gomes B, Pombi M, Sousa CA, Antao T, Dinis J, Bottà G, Mancini E, Petrarca V, Mead D, Drury E, Stalker J, Miles A, Kwiatkowski DP, Donnelly MJ, Rodrigues A, Torre AD, Weetman D, Pinto J. Massive introgression drives species radiation at the range limit of Anopheles gambiae. Sci Rep 2017; 7:46451. [PMID: 28417969 PMCID: PMC5394460 DOI: 10.1038/srep46451] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 03/17/2017] [Indexed: 12/30/2022] Open
Abstract
Impacts of introgressive hybridisation may range from genomic erosion and species collapse to rapid adaptation and speciation but opportunities to study these dynamics are rare. We investigated the extent, causes and consequences of a hybrid zone between Anopheles coluzzii and Anopheles gambiae in Guinea-Bissau, where high hybridisation rates appear to be stable at least since the 1990s. Anopheles gambiae was genetically partitioned into inland and coastal subpopulations, separated by a central region dominated by A. coluzzii. Surprisingly, whole genome sequencing revealed that the coastal region harbours a hybrid form characterised by an A. gambiae-like sex chromosome and massive introgression of A. coluzzii autosomal alleles. Local selection on chromosomal inversions may play a role in this process, suggesting potential for spatiotemporal stability of the coastal hybrid form and providing resilience against introgression of medically-important loci and traits, found to be more prevalent in inland A. gambiae.
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Affiliation(s)
- José L Vicente
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Christopher S Clarkson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Beniamino Caputo
- Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma "Sapienza", Rome, Italy
| | - Bruno Gomes
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Marco Pombi
- Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma "Sapienza", Rome, Italy
| | - Carla A Sousa
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Tiago Antao
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - João Dinis
- Instituto Nacional de Saúde Pública, Ministério da Saúde Pública, Bissau, Guiné-Bissau
| | - Giordano Bottà
- Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma "Sapienza", Rome, Italy.,Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Emiliano Mancini
- Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma "Sapienza", Rome, Italy
| | - Vincenzo Petrarca
- Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma "Sapienza", Rome, Italy.,Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Dipartimento di Biologia e Biotecnologie "Charles Darwin", Università di Roma "Sapienza", Rome, Italy
| | - Daniel Mead
- Wellcome Trust Sanger Institute, Hinxton, UK
| | | | | | - Alistair Miles
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.,Medical Research Council Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Dominic P Kwiatkowski
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.,Wellcome Trust Sanger Institute, Hinxton, UK.,Medical Research Council Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Amabélia Rodrigues
- Instituto Nacional de Saúde Pública, Ministério da Saúde Pública, Bissau, Guiné-Bissau
| | - Alessandra Della Torre
- Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma "Sapienza", Rome, Italy
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - João Pinto
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
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28
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Roux O, Vantaux A, Roche B, Yameogo KB, Dabiré KR, Diabaté A, Simard F, Lefèvre T. Evidence for carry-over effects of predator exposure on pathogen transmission potential. Proc Biol Sci 2017; 282:20152430. [PMID: 26674956 DOI: 10.1098/rspb.2015.2430] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Accumulating evidence indicates that species interactions such as competition and predation can indirectly alter interactions with other community members, including parasites. For example, presence of predators can induce behavioural defences in the prey, resulting in a change in susceptibility to parasites. Such predator-induced phenotypic changes may be especially pervasive in prey with discrete larval and adult stages, for which exposure to predators during larval development can have strong carry-over effects on adult phenotypes. To the best of our knowledge, no study to date has examined possible carry-over effects of predator exposure on pathogen transmission. We addressed this question using a natural food web consisting of the human malaria parasite Plasmodium falciparum, the mosquito vector Anopheles coluzzii and a backswimmer, an aquatic predator of mosquito larvae. Although predator exposure did not significantly alter mosquito susceptibility to P. falciparum, it incurred strong fitness costs on other key mosquito life-history traits, including larval development, adult size, fecundity and longevity. Using an epidemiological model, we show that larval predator exposure should overall significantly decrease malaria transmission. These results highlight the importance of taking into account the effect of environmental stressors on disease ecology and epidemiology.
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Affiliation(s)
- Olivier Roux
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR IRD 224-CNRS 5290-UM, Montpellier, France Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Amélie Vantaux
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR IRD 224-CNRS 5290-UM, Montpellier, France Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Benjamin Roche
- UMMISCO (Unité de Modélisation Mathématique et Informatique des Systèmes Complexes), UMI IRD/UPMC 209, Bondy, France
| | - Koudraogo B Yameogo
- Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Kounbobr R Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Frederic Simard
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR IRD 224-CNRS 5290-UM, Montpellier, France
| | - Thierry Lefèvre
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR IRD 224-CNRS 5290-UM, Montpellier, France Institut de Recherche en Sciences de la Santé (IRSS), 01 BP 545, Bobo-Dioulasso, Burkina Faso
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29
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Akorli J, Gendrin M, Pels NAP, Yeboah-Manu D, Christophides GK, Wilson MD. Seasonality and Locality Affect the Diversity of Anopheles gambiae and Anopheles coluzzii Midgut Microbiota from Ghana. PLoS One 2016; 11:e0157529. [PMID: 27322614 PMCID: PMC4913965 DOI: 10.1371/journal.pone.0157529] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 06/01/2016] [Indexed: 02/01/2023] Open
Abstract
Symbiotic bacteria can have important implications in the development and competence of disease vectors. In Anopheles mosquitoes, the composition of the midgut microbiota is largely influenced by the larval breeding site, but the exact factors shaping this composition are currently unknown. Here, we examined whether the proximity to urban areas and seasons have an impact on the midgut microbial community of the two major malaria vectors in Africa, An. coluzzii and An. gambiae. Larvae and pupae were collected from selected habitats in two districts of Ghana during the dry and rainy season periods. The midgut microbiota of adults that emerged from these collections was determined by 454-pyrosequencing of the 16S ribosomal DNA. We show that in both mosquito species, Shewanellaceae constituted on average of 54% and 73% of the midgut microbiota from each site in the dry and rainy season, respectively. Enterobacteriaceae was found in comparatively low abundance below 1% in 22/30 samples in the dry season, and in 25/38 samples in the rainy season. Our data indicate that seasonality and locality significantly affect both the diversity of microbiota and the relative abundance of bacterial families with a positive impact of dry season and peri-urban settings.
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Affiliation(s)
- Jewelna Akorli
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
- * E-mail:
| | - Mathilde Gendrin
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, Imperial College Road, SW7 2AZ London, United Kingdom
| | - Nana Adjoa P. Pels
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
| | - Dorothy Yeboah-Manu
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
| | - George K. Christophides
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, Imperial College Road, SW7 2AZ London, United Kingdom
| | - Michael D. Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
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30
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Miller SE, Samuk KM, Rennison DJ. An experimental test of the effect of predation upon behaviour and trait correlations in the threespine stickleback. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12790] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Sara E. Miller
- Department of Zoology; University of British Columbia; Vancouver BC Canada
| | - Kieran M. Samuk
- Department of Zoology; University of British Columbia; Vancouver BC Canada
| | - Diana J. Rennison
- Department of Zoology; University of British Columbia; Vancouver BC Canada
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31
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Niang A, Epopa PS, Sawadogo SP, Maïga H, Konaté L, Faye O, Dabiré RK, Tripet F, Diabaté A. Does extreme asymmetric dominance promote hybridization between Anopheles coluzzii and Anopheles gambiae s.s. in seasonal malaria mosquito communities of West Africa? Parasit Vectors 2015; 8:586. [PMID: 26559354 PMCID: PMC4642620 DOI: 10.1186/s13071-015-1190-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/31/2015] [Indexed: 03/13/2023] Open
Abstract
Background Anopheles gambiae s.s. and An. coluzzii are two of the most important malaria vector species in sub-Saharan Africa. These recently-diverged sibling species do not exhibit intrinsic post-zygotic barriers to reproduction and are thought to be separated by strong assortative mating combined with selection against hybrids. At present, little is known about the ecological conditions that determine hybridization and introgression between these cryptic taxa. Methods Swarm segregation and assortative mating were studied in Western Burkina Faso in the villages of Vallée du Kou (VK7) and Soumousso which differed in terms of which sibling species was much rarer than the other, and in Bana where both occurred in similar proportions. Swarms and pairs in copula were collected and genotyped, the proportion of intra and interspecific mating determined, and interspecific sperm transfer checked genetically. Females were collected through larval and adult indoor collections and genotyped or sexed-and-genotyped via a novel multiplex PCR. Results A total of 3,687 males and 220 females were collected and genotyped from 109 swarms. Only 3 swarms were composed of males from both species, and these were from the village of VK7 where An. gambiae s.s. was comparatively rare. Mixed-species pairs captured in copula were only detected in that area and made for 3.62 % and 100 % of mating pairs involving An. coluzzii and An. gambiae s.s. individuals, respectively. The high An. gambiae s.s. cross-mating rate was mirrored by high rates of hybridizations estimated from female larvae and adults indoor collections. This contrasted with Soumousso, where despite being much less common than An. gambiae s.s., An. coluzzii males did not form mixed swarms, females were not found in interspecific swarms or copula and hybridization rates were low in both sibling species. Conclusions These data suggest that ecological conditions leading to rare An. gambiae s.s. in populations dominated by An. coluzzii may promote a breakdown of spatial swarm segregation and assortative mating between the two species. The lower overall hybridization rates observed at the larval and adult indoor stages compared to cross-mating rates support the idea that post-mating selection processes acting against hybrids may occur mostly prior to and/or at the early larval stages.
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Affiliation(s)
- Abdoulaye Niang
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
| | - Patric S Epopa
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
| | - Simon P Sawadogo
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
| | - Hamidou Maïga
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
| | - Lassana Konaté
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Senegal.
| | - Ousmane Faye
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Senegal.
| | - Roch K Dabiré
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
| | - Frédéric Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, UK.
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
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Gomes B, Wilding CS, Weetman D, Sousa CA, Novo MT, Savage HM, Almeida APG, Pinto J, Donnelly MJ. Limited genomic divergence between intraspecific forms of Culex pipiens under different ecological pressures. BMC Evol Biol 2015; 15:197. [PMID: 26377220 PMCID: PMC4573496 DOI: 10.1186/s12862-015-0477-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 09/03/2015] [Indexed: 01/01/2023] Open
Abstract
Background Divergent selection can be a major driver of ecological speciation. In insects of medical importance, understanding the speciation process is both of academic interest and public health importance. In the West Nile virus vector Culex pipiens, intraspecific pipiens and molestus forms vary in ecological and physiological traits. Populations of each form appear to share recent common ancestry but patterns of genetic differentiation across the genome remain unknown. Here, we undertook an AFLP genome scan on samples collected from both sympatric and allopatric populations from Europe and the USA to quantify the extent of genomic differentiation between the two forms. Results The forms were clearly differentiated but each exhibited major population sub-structuring between continents. Divergence between pipiens and molestus forms from USA was higher than in both inter- and intra-continental comparisons with European samples. The proportion of outlier loci between pipiens and molestus (≈3 %) was low but consistent in both continents, and similar to those observed between sibling species of other mosquito species which exhibit contemporary gene flow. Only two of the outlier loci were shared between inter-form comparisons made within Europe and USA. Conclusion This study supports the molestus and pipiens status as distinct evolutionary entities with low genomic divergence. The low number of shared divergent loci between continents suggests a relatively limited number of genomic regions determining key typological traits likely to be driving incipient speciation and/or adaptation of molestus to anthropogenic habitats. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0477-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bruno Gomes
- Global Health & Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008, Lisbon, Portugal. .,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Craig S Wilding
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. .,School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, L3 3AF, UK.
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Carla A Sousa
- Global Health & Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.
| | - Maria T Novo
- Global Health & Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.
| | - Harry M Savage
- Centers for Disease Control and Prevention, 3156 Rampart Road, Fort Collins, CO, 80521, USA.
| | - António P G Almeida
- Global Health & Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.
| | - João Pinto
- Global Health & Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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Experimental swap of Anopheles gambiae's assortative mating preferences demonstrates key role of X-chromosome divergence island in incipient sympatric speciation. PLoS Genet 2015; 11:e1005141. [PMID: 25880677 PMCID: PMC4400153 DOI: 10.1371/journal.pgen.1005141] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/11/2015] [Indexed: 12/12/2022] Open
Abstract
Although many theoretical models of sympatric speciation propose that genes responsible for assortative mating amongst incipient species should be associated with genomic regions protected from recombination, there are few data to support this theory. The malaria mosquito, Anopheles gambiae, is known for its sympatric cryptic species maintained by pre-mating reproductive isolation and its putative genomic islands of speciation, and is therefore an ideal model system for studying the genomic signature associated with incipient sympatric speciation. Here we selectively introgressed the island of divergence located in the pericentric region of the X chromosome of An. gambiae s.s. into its sister taxon An. coluzzii through 5 generations of backcrossing followed by two generations of crosses within the introgressed strains that resulted in An. coluzzii-like recombinant strains fixed for the M and S marker in the X chromosome island. The mating preference of recombinant strains was then tested by giving virgin recombinant individuals a choice of mates with X-islands matching and non-matching their own island type. We show through genetic analyses of transferred sperm that recombinant females consistently mated with matching island-type males thereby associating assortative mating genes with the X-island of divergence. Furthermore, full-genome sequencing confirmed that protein-coding differences between recombinant strains were limited to the experimentally swapped pericentromeric region. Finally, targeted-genome comparisons showed that a number of these unique differences were conserved in sympatric field populations, thereby revealing candidate speciation genes. The functional demonstration of a close association between speciation genes and the X-island of differentiation lends unprecedented support to island-of-speciation models of sympatric speciation facilitated by pericentric recombination suppression. Anopheles gambiae is the most important vector of malaria in Africa. This species is undergoing speciation and a number of subpopulations have been identified which can produce viable hybrid offspring but are reproductively isolated through assortative mating and ecological adaptation. This complex structure provides an ideal system for studying the unique genetic and behavioural processes required for speciation. Anopheles gambiae’s subpopulations differ genetically in limited regions of their genomes called islands of speciation. Theoretical studies predict that these islands, characterized by restricted genetic rearrangements, may protect genes of assortative mating between emerging species, and are fundamental to the speciation process. We set out to test this prediction by performing complex genetic crosses between the sister species Anopheles coluzzii and Anopheles gambiae s.s. and creating recombinant strains differing only at their X-chromosome island of speciation. We show through behavioural studies that recombinant females consistently mated with matching island-type males thereby associating assortative mating genes with the X-island of divergence. By sequencing the genetic code of the recombinant strains and natural populations, we could confirm these findings and identify candidate assortative mating genes. These findings suggest an important role of divergence islands for the genetic and behavioural processes associated with speciation.
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Tene Fossog B, Ayala D, Acevedo P, Kengne P, Ngomo Abeso Mebuy I, Makanga B, Magnus J, Awono-Ambene P, Njiokou F, Pombi M, Antonio-Nkondjio C, Paupy C, Besansky NJ, Costantini C. Habitat segregation and ecological character displacement in cryptic African malaria mosquitoes. Evol Appl 2015; 8:326-45. [PMID: 25926878 PMCID: PMC4408144 DOI: 10.1111/eva.12242] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 12/08/2014] [Indexed: 01/09/2023] Open
Abstract
Understanding how divergent selection generates adaptive phenotypic and population diversification provides a mechanistic explanation of speciation in recently separated species pairs. Towards this goal, we sought ecological gradients of divergence between the cryptic malaria vectors Anopheles coluzzii and An. gambiae and then looked for a physiological trait that may underlie such divergence. Using a large set of occurrence records and eco-geographic information, we built a distribution model to predict the predominance of the two species across their range of sympatry. Our model predicts two novel gradients along which the species segregate: distance from the coastline and altitude. Anopheles coluzzii showed a ‘bimodal’ distribution, predominating in xeric West African savannas and along the western coastal fringe of Africa. To test whether differences in salinity tolerance underlie this habitat segregation, we assessed the acute dose–mortality response to salinity of thirty-two larval populations from Central Africa. In agreement with its coastal predominance, Anopheles coluzzii was overall more tolerant than An. gambiae. Salinity tolerance of both species, however, converged in urban localities, presumably reflecting an adaptive response to osmotic stress from anthropogenic pollutants. When comparing degree of tolerance in conjunction with levels of syntopy, we found evidence of character displacement in this trait.
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Affiliation(s)
- Billy Tene Fossog
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon ; Department of Animal Biology, Faculty of Sciences, University of Yaoundé I Yaoundé, Cameroon
| | - Diego Ayala
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Eck Institute for Global Health & Department of Biological Sciences, University of Notre Dame Notre Dame, IN, USA ; Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon
| | - Pelayo Acevedo
- SaBio, Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM Ciudad Real, Spain
| | - Pierre Kengne
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
| | | | - Boris Makanga
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon ; Institut de Recherche en Ecologie Tropicale (IRET) Libreville, Gabon
| | - Julie Magnus
- Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology, Faculty of Sciences, University of Yaoundé I Yaoundé, Cameroon
| | - Marco Pombi
- Sezione di Parassitologia, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma 'La Sapienza' Rome, Italy
| | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
| | - Christophe Paupy
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon
| | - Nora J Besansky
- Eck Institute for Global Health & Department of Biological Sciences, University of Notre Dame Notre Dame, IN, USA
| | - Carlo Costantini
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
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Hidalgo K, Dujardin JP, Mouline K, Dabiré RK, Renault D, Simard F. Seasonal variation in wing size and shape between geographic populations of the malaria vector, Anopheles coluzzii in Burkina Faso (West Africa). Acta Trop 2015; 143:79-88. [PMID: 25579425 DOI: 10.1016/j.actatropica.2014.12.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 12/16/2014] [Accepted: 12/26/2014] [Indexed: 11/24/2022]
Abstract
The mosquito, Anopheles coluzzii is a major vector of human malaria in Africa with widespread distribution throughout the continent. The species hence populates a wide range of environments in contrasted ecological settings often exposed to strong seasonal fluctuations. In the dry savannahs of West Africa, this mosquito population dynamics closely follows the pace of surface water availability: the species pullulates during the rainy season and is able to reproduce throughout the dry season in areas where permanent water bodies are available for breeding. The impact of such environmental fluctuation on mosquito development and the phenotypic quality of emerging adults has however not been addressed in details. Here, we examined and compared phenotypic changes in the duration of pre-imaginal development, body dry mass at emergence and wing size, shape and surface area in young adult females An. coluzzii originated from five distinct geographic locations when they are reared in two contrasting conditions mimicking those experienced by mosquitoes during the rainy season (RS) and at the onset of the dry season (ODS) in Burkina Faso (West Africa). Our results demonstrated strong phenotypic plasticity in all traits, with differences in the magnitude and direction of changes between RS and ODS depending upon the geographic origin, hence the genetic background of the mosquito populations. Highest heterogeneity within population was observed in Bama, where large irrigation schemes allow year-round mosquito breeding. Further studies are needed to explore the adaptive value of such phenotypic plasticity and its relevance for local adaptation in An. coluzzii.
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Hardwick KM, Harmon LJ, Hardwick SD, Rosenblum EB. When field experiments yield unexpected results: lessons learned from measuring selection in White Sands lizards. PLoS One 2015; 10:e0118560. [PMID: 25714838 PMCID: PMC4340912 DOI: 10.1371/journal.pone.0118560] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 01/20/2015] [Indexed: 12/03/2022] Open
Abstract
Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected.
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Affiliation(s)
- Kayla M. Hardwick
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
- * E-mail:
| | - Luke J. Harmon
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
| | - Scott D. Hardwick
- Department of Mechanical Engineering, University of Idaho, Moscow, Idaho, United States of America
| | - Erica Bree Rosenblum
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, United States of America
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Kiszewski AE, Teffera Z, Wondafrash M, Ravesi M, Pollack RJ. Ecological succession and its impact on malaria vectors and their predators in borrow pits in western Ethiopia. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2014; 39:414-423. [PMID: 25424271 DOI: 10.1111/jvec.12117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 10/01/2014] [Indexed: 06/04/2023]
Abstract
Soil pits excavated for home construction are important larval habitats for malaria vectors in certain parts of Africa. Borrow pits in diverse stages of ecological succession in a maize-farming region of Western Ethiopia were surveyed to assess the relationships between stage of succession and the structure and composition of invertebrate and plant communities, with particular attention to Anopheles gambiae s.l. and An. coustani, the primary local malaria vectors. An array of 82 borrow pits was identified in a multi-lobed drainage basin in the community of Woktola. Each pit was evaluated on its physical features and by faunal and floral surveys during August, 2011, at the height of the longer rainy season (kiremt). Anopheles gambiae s.l. and An. coustani were the sole immature anophelines collected, often coexisting with Culex spp. Sedges were the most common plants within these pits, and included Cyperus elegantulus, C. flavescens, C. erectus and C. assimilis. The legume Smithia abyssinica, Nile grass (Acroceras macrum), cutgrass (Leersia hexandra), clover (Trifolium spp.), and the edible herb Centella asiatica, were also common in these habitats. No plant species in particular was strongly and consistently predictive of the presence or absence of mosquito immatures, particularly with regard to An. coustani. The presence of An.gambiae s.l. immatures in borrow pit habitats was negatively correlated with the presence of backswimmers (Notonectidae) (Z = -2.34, P = 0.019). Young (freshly excavated) borrow pits more likely contained immature An. gambiae s.l. (Z =-2.86, P=0.004). Ecological succession was apparent in older pits, and as they aged, they became less likely to serve as habitats for An. gambiae s.l. (Z=0.26, P=0.796), and more likely to support An. coustani (Z=0.728, P=0.007). As borrow pits age they become less suitable for An. gambiae s.l. breeding and more likely to harbor An. coustani. The abundance of notonectids in habitats was a negative indicator for An. gambiae s.l. abundance. Plant species are not reliable indicators for the presence or absence of malaria vectors in borrow pits.
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Affiliation(s)
- Anthony E Kiszewski
- Department of Natural and Applied Sciences, Bentley University, Waltham, MA 02452, U.S.A..
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Gordicho V, Vicente JL, Sousa CA, Caputo B, Pombi M, Dinis J, Seixas G, Palsson K, Weetman D, Rodrigues A, della Torre A, Pinto J. First report of an exophilic Anopheles arabiensis population in Bissau City, Guinea-Bissau: recent introduction or sampling bias? Malar J 2014; 13:423. [PMID: 25370807 PMCID: PMC4240859 DOI: 10.1186/1475-2875-13-423] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/25/2014] [Indexed: 11/23/2022] Open
Abstract
Background The malaria vector Anopheles arabiensis exhibits greater behavioural and ecological plasticity than the other major vectors of the Anopheles gambiae complex, which presents challenges for major control methods. This study reports for the first time the presence of An. arabiensis in Antula, a suburb of Bissau city, the capital of Guinea Bissau, where high levels of hybridization between Anopheles coluzzii and An. gambiae have been reported. Given that previous surveys in the area, based on indoor collections, did not sample An. arabiensis, the possibility of a recently introduced exophilic population was investigated. Methods Larval and adult mosquito collections were carried out in Antula at the end of the rainy season of 2010. Anopheles gambiae species composition, determined by rDNA-IGS and SINE200X6.1 markers, was compared with four previously collected samples dating back to 1993. Analysis of ten microsatellites was used to estimate levels of genetic diversity, relatedness and to investigate demographic stability. Results Anopheles arabiensis comprised 54.0% of larvae and 25.6% of adults collected in 2010, but was absent in all previous collections, a highly unlikely observation by chance if the population was stable. This species had the lowest levels of genetic diversity, highest relatedness and, along with An. gambiae, exhibited evidence of a recent population expansion. Conclusions Results point to the presence of a previously undetected outdoor population of An. arabiensis in Antula, which appears to have expanded recently, highlighting the importance of complementing indoor-based mosquito collections with sampling methods targeting outdoor adults and immature stages for a more complete assessment of mosquito biodiversity. A change in temporal dynamics in the species complex composition was also detected. Coupled with previous evidence of asymmetric introgression from An. coluzzii to An. gambiae, this suggests that the study area may be subject to ecological changes with a potential impact on both the genetics of these species and on malaria transmission. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-423) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - João Pinto
- UEI Parasitologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1349-008 Lisbon, Portugal.
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Caputo B, Nwakanma D, Caputo FP, Jawara M, Oriero EC, Hamid-Adiamoh M, Dia I, Konate L, Petrarca V, Pinto J, Conway DJ, Della Torre A. Prominent intraspecific genetic divergence within Anopheles gambiae sibling species triggered by habitat discontinuities across a riverine landscape. Mol Ecol 2014; 23:4574-89. [PMID: 25040079 DOI: 10.1111/mec.12866] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/09/2014] [Accepted: 07/16/2014] [Indexed: 01/09/2023]
Abstract
The Anopheles gambiae complex of mosquitoes includes malaria vectors at different stages of speciation, whose study enables a better understanding of how adaptation to divergent environmental conditions leads to evolution of reproductive isolation. We investigated the population genetic structure of closely related sympatric taxa that have recently been proposed as separate species (An. coluzzii and An. gambiae), sampled from diverse habitats along the Gambia river in West Africa. We characterized putatively neutral microsatellite loci as well as chromosomal inversion polymorphisms known to be associated with ecological adaptation. The results revealed strong ecologically associated population subdivisions within both species. Microsatellite loci on chromosome-3L revealed clear differentiation between coastal and inland populations, which in An. coluzzii is reinforced by a unusual inversion polymorphism pattern, supporting the hypothesis of genetic divergence driven by adaptation to the coastal habitat. A strong reduction of gene flow was observed between An. gambiae populations west and east of an extensively rice-cultivated region apparently colonized exclusively by An. coluzzii. Notably, this 'intraspecific' differentiation is higher than that observed between the two species and involves also the centromeric region of chromosome-X which has previously been considered a marker of speciation within this complex, possibly suggesting that the two populations may be at an advanced stage of differentiation triggered by human-made habitat fragmentation. These results confirm ongoing ecological speciation within these most important Afro-tropical malaria vectors and raise new questions on the possible effect of this process in malaria transmission.
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Affiliation(s)
- B Caputo
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur-Fondazione Cenci-Bolognetti, Università 'Sapienza', Piazzale Aldo Moro 5, 00185, Rome, Italy
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Angêlla AF, Salgueiro P, Gil LHS, Vicente JL, Pinto J, Ribolla PEM. Seasonal genetic partitioning in the neotropical malaria vector, Anopheles darlingi. Malar J 2014; 13:203. [PMID: 24885508 PMCID: PMC4059831 DOI: 10.1186/1475-2875-13-203] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 05/21/2014] [Indexed: 11/10/2022] Open
Abstract
Background Anopheles darlingi is the main malaria mosquito vector in the Amazonia region. In spite of being considered a riverine, forest-dwelling species, this mosquito is becoming more abundant in peri-urban areas, increasing malaria risk. This has been associated with human-driven environmental changes such as deforestation. Methods Microsatellites were used to characterize A. darlingi from seven localities along the Madeira River, Rondônia (Brazil), collected in the early and late periods of the rainy season. Results Two genetically distinct subpopulations were detected: one (subpopulation A) was associated with the late rainfall period and seems to be ecologically closer to the typical forest A. darlingi; the other (subpopulation B) was associated with the early rainfall period and is probably more adapted to drier conditions by exploiting permanent anthropogenic breeding sites. Results suggest also a pattern of asymmetric introgression, with more subpopulation A alleles introgressed into subpopulation B. Both subpopulations (and admixed mosquitoes) presented similar malaria infection rates, highlighting the potential for perennial malaria transmission in the region. Conclusions The co-occurrence of two genetically distinct subpopulations of A. darlingi adapted to different periods of rainfall may promote a more perennial transmission of malaria throughout the year. These findings, in a context of strong environmental impact due to deforestation and dam construction, have serious implications for malaria epidemiology and control in the Amazonian region.
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Affiliation(s)
| | | | | | | | | | - Paulo E M Ribolla
- Departamento de Parasitologia, Instituto de Biociências, Universidade Estadual Paulista "Júlio de Mesquita Neto", Botucatu, SP, Brasil.
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Cassone BJ, Kamdem C, Cheng C, Tan JC, Hahn MW, Costantini C, Besansky NJ. Gene expression divergence between malaria vector sibling species Anopheles gambiae and An. coluzzii from rural and urban Yaoundé Cameroon. Mol Ecol 2014; 23:2242-59. [PMID: 24673723 DOI: 10.1111/mec.12733] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 03/05/2014] [Accepted: 03/05/2014] [Indexed: 01/07/2023]
Abstract
Divergent selection based on aquatic larval ecology is a likely factor in the recent isolation of two broadly sympatric and morphologically identical African mosquito species, the malaria vectors Anopheles gambiae and An. coluzzii. Population-based genome scans have revealed numerous candidate regions of recent positive selection, but have provided few clues as to the genetic mechanisms underlying behavioural and physiological divergence between the two species, phenotypes which themselves remain obscure. To uncover possible genetic mechanisms, we compared global transcriptional profiles of natural and experimental populations using gene-based microarrays. Larvae were sampled as second and fourth instars from natural populations in and around the city of Yaoundé, capital of Cameroon, where the two species segregate along a gradient of urbanization. Functional enrichment analysis of differentially expressed genes revealed that An. coluzzii--the species that breeds in more stable, biotically complex and potentially polluted urban water bodies--overexpresses genes implicated in detoxification and immunity relative to An. gambiae, which breeds in more ephemeral and relatively depauperate pools and puddles in suburbs and rural areas. Moreover, our data suggest that such overexpression by An. coluzzii is not a transient result of induction by xenobiotics in the larval habitat, but an inherent and presumably adaptive response to repeatedly encountered environmental stressors. Finally, we find no significant overlap between the differentially expressed loci and previously identified genomic regions of recent positive selection, suggesting that transcriptome divergence is regulated by trans-acting factors rather than cis-acting elements.
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Affiliation(s)
- Bryan J Cassone
- Eck Institute for Global Health & Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556-0369, USA
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Moiroux N, Djènontin A, Bio-Bangana AS, Chandre F, Corbel V, Guis H. Spatio-temporal analysis of abundances of three malaria vector species in southern Benin using zero-truncated models. Parasit Vectors 2014; 7:103. [PMID: 24620714 PMCID: PMC4008307 DOI: 10.1186/1756-3305-7-103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 03/03/2014] [Indexed: 11/23/2022] Open
Abstract
Background A better understanding of the ecology and spatial-temporal distribution of malaria vectors is essential to design more effective and sustainable strategies for malaria control and elimination. In a previous study, we analyzed presence-absence data of An. funestus, An. coluzzii, and An. gambiae s.s. in an area of southern Benin with high coverage of vector control measures. Here, we further extend the work by analysing the positive values of the dataset to assess the determinants of the abundance of these three vectors and to produce predictive maps of vector abundance. Methods Positive counts of the three vectors were assessed using negative-binomial zero-truncated (NBZT) mixed-effect models according to vector control measures and environmental covariates derived from field and remote sensing data. After 8-fold cross-validation of the models, predictive maps of abundance of the sympatric An. funestus, An. coluzzii, and An. gambiae s.s. were produced. Results Cross-validation of the NBZT models showed a satisfactory predictive accuracy. Almost all changes in abundance between two surveys in the same village were well predicted by the models but abundances for An. gambiae s.s. were slightly underestimated. During the dry season, predictive maps showed that abundance greater than 1 bite per person per night were observed only for An. funestus and An. coluzzii. During the rainy season, we observed both increase and decrease in abundance of An. funestus, which are dependent on the ecological setting. Abundances of both An. coluzzii and An. gambiae s.s. increased during the rainy season but not in the same areas. Conclusions Our models helped characterize the ecological preferences of three major African malaria vectors. This works highlighted the importance to study independently the binomial and the zero-truncated count processes when evaluating vector control strategies. The study of the bio-ecology of malaria vector species in time and space is critical for the implementation of timely and efficient vector control strategies.
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Affiliation(s)
- Nicolas Moiroux
- MIVEGEC (IRD 224-CNRS 5290-UM1-UM2), Institut de Recherche pour le Développement (IRD), BP64501, 34394 Montpellier, France.
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Gimonneau G, Brossette L, Mamaï W, Dabiré RK, Simard F. Larval competition between An. coluzzii and An. gambiae in insectary and semi-field conditions in Burkina Faso. Acta Trop 2014; 130:155-61. [PMID: 24269743 DOI: 10.1016/j.actatropica.2013.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 11/01/2013] [Accepted: 11/09/2013] [Indexed: 12/20/2022]
Abstract
Competition in mosquito larvae is common and different ecological context could change competitive advantage between species. Here, larval competition between the widely sympatric African malaria mosquitoes, Anopheles coluzzii and Anopheles gambiae were investigated in controlled insectary conditions using individuals from laboratory colonies and under ambient conditions using wild mosquitoes in a semi-field enclosure in western Burkina Faso. Larvae of both species were reared in trays at the same larval density and under the same feeding regimen in either single-species or mixed-species populations at varying species ratios reflecting 0%, 25%, 50% and 75% of competitor species. In the insectaries, where environmental variations are controlled, larvae of the An. coluzzii colony developed faster and with lower mortality than larvae of the An. gambiae colony (8.8±0.1 days and 21±3% mortality vs. 9.5±0.1 days and 32±3% mortality, respectively). Although there was no significant effect of competition on these phenotypic traits in any species, there was a significant trend for higher fitness of the An. coluzzii colony when competing with An. gambiae under laboratory conditions (i.e. lower development time and increased wing length at emergence, Cuzik's tests, P<0.05). In semi-field experiments, competition affected the life history traits of both species in a different way. Larvae of An. gambiae tended to reduce development time when in competition with An. coluzzii (Cuzick's test, P=0.002) with no impact either on mortality or size at emergence. On the other hand, An. coluzzii showed a significant trend for reduced larval mortality with increasing competition pressure (Cuzick's test, P=0.037) and production of smaller females when grown together with An. gambiae (Cuzick's test, P=0.002). Our results hence revealed that competitive interactions between larvae of the two species are context dependent. They further call for caution when exploring ecological processes using inbred laboratory colonies in this system of utmost medical importance.
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Affiliation(s)
- Geoffrey Gimonneau
- Institut de Recherche pour le Développement (IRD), UMR 224-CNRS 5290-Université de Montpellier 1-Université de Montpellier 2 MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Genetique, Evolution et Contrôle), team BEES (Biology, Ecology and Evolution of vector Systems), 911 Avenue Agropolis, BP 64501, 34394 Montpellier, France; Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest (DRO), 399 Avenue de la Liberté, 01 BP 545 Bobo Dioulasso, Burkina Faso.
| | - Lou Brossette
- Institut de Recherche pour le Développement (IRD), UMR 224-CNRS 5290-Université de Montpellier 1-Université de Montpellier 2 MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Genetique, Evolution et Contrôle), team BEES (Biology, Ecology and Evolution of vector Systems), 911 Avenue Agropolis, BP 64501, 34394 Montpellier, France.
| | - Wadaka Mamaï
- Institut de Recherche pour le Développement (IRD), UMR 224-CNRS 5290-Université de Montpellier 1-Université de Montpellier 2 MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Genetique, Evolution et Contrôle), team BEES (Biology, Ecology and Evolution of vector Systems), 911 Avenue Agropolis, BP 64501, 34394 Montpellier, France; Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest (DRO), 399 Avenue de la Liberté, 01 BP 545 Bobo Dioulasso, Burkina Faso.
| | - Roch K Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest (DRO), 399 Avenue de la Liberté, 01 BP 545 Bobo Dioulasso, Burkina Faso.
| | - Frédéric Simard
- Institut de Recherche pour le Développement (IRD), UMR 224-CNRS 5290-Université de Montpellier 1-Université de Montpellier 2 MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Genetique, Evolution et Contrôle), team BEES (Biology, Ecology and Evolution of vector Systems), 911 Avenue Agropolis, BP 64501, 34394 Montpellier, France; Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest (DRO), 399 Avenue de la Liberté, 01 BP 545 Bobo Dioulasso, Burkina Faso.
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Roux O, Diabaté A, Simard F. Divergence in threat sensitivity among aquatic larvae of cryptic mosquito species. J Anim Ecol 2013; 83:702-11. [PMID: 24138173 DOI: 10.1111/1365-2656.12163] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 10/13/2013] [Indexed: 11/29/2022]
Abstract
Predation is a major evolutionary force driving speciation. The threat-sensitive response hypothesis predicts that prey adjust and balance the time spent on a costly antipredator response with other activities that enhance their fitness. Thus, prey able to develop an antipredator response proportional to risk intensity should have a selective advantage. Knowledge on how evolution has shaped threat sensitivity among closely related species exposed to different predation pressures is scarce, prompting investigations to better predict and explain its effect on communities. We explored and compared the antipredator response of aquatic mosquito larvae in three sibling species of the Anopheles gambiae complex, with contrasting larval biologies in Burkina Faso. Anopheles arabiensis and An. gambiae sensu stricto breed in temporary water collections where predator densities are low, whereas Anopheles coluzzii is able to thrive in permanent pools where the predation pressure is much higher. We hypothesized that the increase and decline of behavioural antipredator responses might differ between the three species over time. To test this hypothesis, progenies of field-collected mosquitoes were experimentally exposed to a range of soluble predation cues and their response was monitored for up to 48 h. The three species were all threat sensitive but their reaction norms differed. For the range of concentrations tested, An. coluzzii larvae gradually increased in antipredator response, whereas An. gambiae larvae readily displayed antipredator behaviour at low concentrations leading to a saturation of the response for high cue concentrations. An. arabiensis displayed a narrower reaction norm with low response intensity. Larval instars did not differ in their threat sensitivity. The antipredator behaviour of the three species waned after about 1 h of exposure. Early instars tended to express antipredation behaviour for longer than did older instars. This study provides information on how aquatic prey species with an aerial adult stage manage larval predation risk over time according to cue concentrations and suggests that different predation pressures might play a role as a disruptive selective force fostering habitat segregation and speciation within the An. gambiae complex. The evolution of phenotypic plasticity is further discussed in the light of divergent predation pressures.
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Affiliation(s)
- Olivier Roux
- Institut de Recherche pour le Développement, UMR IRD224-CNRS5290-UM1-UM2 MiVEGEC (Infectious Diseases and Vectors: Ecology, Genetics, Evolution, and Control), 911 Avenue Agropolis, BP 64501, 34394, Montpellier, France.,Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest (DRO), BP 390, Bobo Dioulasso, Burkina Faso
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest (DRO), BP 390, Bobo Dioulasso, Burkina Faso
| | - Frédéric Simard
- Institut de Recherche pour le Développement, UMR IRD224-CNRS5290-UM1-UM2 MiVEGEC (Infectious Diseases and Vectors: Ecology, Genetics, Evolution, and Control), 911 Avenue Agropolis, BP 64501, 34394, Montpellier, France
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Mullen SP, Shaw KL. Insect speciation rules: unifying concepts in speciation research. ANNUAL REVIEW OF ENTOMOLOGY 2013; 59:339-361. [PMID: 24160421 DOI: 10.1146/annurev-ento-120710-100621] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The study of speciation is concerned with understanding the connection between causes of divergent evolution and the origin and maintenance of barriers to gene exchange between incipient species. Although the field has historically focused either on examples of recent divergence and its causes or on the genetic basis of reproductive isolation between already divergent species, current efforts seek to unify these two approaches. Here we integrate these perspectives through a discussion of recent progress in several insect speciation model systems. We focus on the evolution of speciation phenotypes in each system (i.e., those phenotypes causally involved in reducing gene flow between incipient species), drawing an explicit connection between cause and effect (process and pattern). We emphasize emerging insights into the genomic architecture of speciation as well as timely areas for future research.
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Affiliation(s)
- Sean P Mullen
- Department of Biology, Boston University, Boston, Massachusetts 02215;
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Oluwagbemi OO, Fornadel CM, Adebiyi EF, Norris DE, Rasgon JL. ANOSPEX: a stochastic, spatially explicit model for studying Anopheles metapopulation dynamics. PLoS One 2013; 8:e68040. [PMID: 23861847 PMCID: PMC3704604 DOI: 10.1371/journal.pone.0068040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 05/29/2013] [Indexed: 01/23/2023] Open
Abstract
Anopheles mosquitoes transmit malaria, a major public health problem among many African countries. One of the most effective methods to control malaria is by controlling the Anopheles mosquito vectors that transmit the parasites. Mathematical models have both predictive and explorative utility to investigate the pros and cons of different malaria control strategies. We have developed a C++ based, stochastic spatially explicit model (ANOSPEX; Ano pheles Spatially-Explicit) to simulate Anopheles metapopulation dynamics. The model is biologically rich, parameterized by field data, and driven by field-collected weather data from Macha, Zambia. To preliminarily validate ANOSPEX, simulation results were compared to field mosquito collection data from Macha; simulated and observed dynamics were similar. The ANOSPEX model will be useful in a predictive and exploratory manner to develop, evaluate and implement traditional and novel strategies to control malaria, and for understanding the environmental forces driving Anopheles population dynamics.
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Affiliation(s)
- Olugbenga O. Oluwagbemi
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and the Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Department of Computer and Information Sciences, College of Science and Technology, School of Natural and Applied Sciences, Covenant University, Ota, Ogun State, Nigeria
| | - Christen M. Fornadel
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and the Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Ezekiel F. Adebiyi
- Department of Computer and Information Sciences, College of Science and Technology, School of Natural and Applied Sciences, Covenant University, Ota, Ogun State, Nigeria
| | - Douglas E. Norris
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and the Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Jason L. Rasgon
- The Department of Entomology, Center for Infectious Disease Dynamics and Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
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Sanford MR, Ramsay S, Cornel AJ, Marsden CD, Norris LC, Patchoke S, Fondjo E, Lanzaro GC, Lee Y. A preliminary investigation of the relationship between water quality and Anopheles gambiae larval habitats in Western Cameroon. Malar J 2013; 12:225. [PMID: 23819866 PMCID: PMC3704728 DOI: 10.1186/1475-2875-12-225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 06/24/2013] [Indexed: 11/16/2022] Open
Abstract
Background Water quality and anopheline habitat have received increasing attention due to the possibility that challenges during larval life may translate into adult susceptibility to malaria parasite infection and/or insecticide resistance. Methods A preliminary study of Anopheles gambiae s.s. larval habitats in the north-west and south-west regions of Cameroon was conducted in order to detect associations between An. gambiae s.s. molecular form and 2La inversion distributions with basic water quality parameters. Water quality was measured by temperature, pH, conductivity, total dissolved solids (TDS) at seven sites in Cameroon and one site in Selinkenyi, Mali. Results Principal components and correlation analyses indicated a complex relationship between 2La polymorphism, temperature, conductivity and TDS. Cooler water sites at more inland locations yielded more S form larvae with higher 2La inversion polymorphism while warmer water sites yielded more M form larvae with rare observations of the 2La inversion. Discussion More detailed studies that take into account the population genetics but also multiple life stages, environmental data relative to these life stages and interactions with both humans and the malaria parasite may help us to understand more about how and why this successful mosquito is able to adapt and diverge, and how it can be successfully managed.
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Pinto J, Egyir-Yawson A, Vicente J, Gomes B, Santolamazza F, Moreno M, Charlwood J, Simard F, Elissa N, Weetman D, Donnelly M, Caccone A, Della Torre A. Geographic population structure of the African malaria vector Anopheles gambiae suggests a role for the forest-savannah biome transition as a barrier to gene flow. Evol Appl 2013; 6:910-24. [PMID: 24062800 PMCID: PMC3779092 DOI: 10.1111/eva.12075] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 04/29/2013] [Indexed: 11/30/2022] Open
Abstract
The primary Afrotropical malaria mosquito vector Anopheles gambiae sensu stricto has a complex population structure. In west Africa, this species is split into two molecular forms and displays local and regional variation in chromosomal arrangements and behaviors. To investigate patterns of macrogeographic population substructure, 25 An. gambiae samples from 12 African countries were genotyped at 13 microsatellite loci. This analysis detected the presence of additional population structuring, with the M-form being subdivided into distinct west, central, and southern African genetic clusters. These clusters are coincident with the central African rainforest belt and northern and southern savannah biomes, which suggests restrictions to gene flow associated with the transition between these biomes. By contrast, geographically patterned population substructure appears much weaker within the S-form.
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Affiliation(s)
- J Pinto
- Unidade de Parasitologia Médica, Centro de Malária e outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa Lisbon, Portugal
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Reidenbach KR, Neafsey DE, Costantini C, Sagnon N, Simard F, Ragland GJ, Egan SP, Feder JL, Muskavitch MAT, Besansky NJ. Patterns of genomic differentiation between ecologically differentiated M and S forms of Anopheles gambiae in West and Central Africa. Genome Biol Evol 2013; 4:1202-12. [PMID: 23132896 PMCID: PMC3542583 DOI: 10.1093/gbe/evs095] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Anopheles gambiae M and S are thought to be undergoing ecological speciation by adapting to different larval habitats. Toward an improved understanding of the genetic determinants and evolutionary processes shaping their divergence, we used a 400,000 single-nucleotide polymorphism (SNP) genotyping array to characterize patterns of genomic differentiation between four geographically paired M and S population samples from West and Central Africa. In keeping with recent studies based on more limited genomic or geographic sampling, divergence was not confined to a few isolated "speciation islands." Divergence was both widespread across the genome and heterogeneous. Moreover, we find consistent patterns of genomic divergence across sampling sites and mutually exclusive clustering of M and S populations using genetic distances based on all 400,000 SNPs, implying that M and S are evolving collectively across the study area. Nevertheless, the clustering of local M and S populations using genetic distances based on SNPs from genomic regions of low differentiation is consistent with recent gene flow and introgression. To account for these data and reconcile apparent paradoxes in reported patterns of M-S genomic divergence and hybridization, we propose that extrinsic ecologically based postmating barriers vary in strength as environmental conditions fluctuate or change.
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Affiliation(s)
- Kyanne R Reidenbach
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
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Modelling the risk of being bitten by malaria vectors in a vector control area in southern Benin, west Africa. Parasit Vectors 2013; 6:71. [PMID: 23497700 PMCID: PMC3605808 DOI: 10.1186/1756-3305-6-71] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 03/06/2013] [Indexed: 01/18/2023] Open
Abstract
Background The diversity of malaria vector populations, expressing various resistance and/or behavioural patterns could explain the reduced effectiveness of vector control interventions reported in some African countries. A better understanding of the ecology and distribution of malaria vectors is essential to design more effective and sustainable strategies for malaria control and elimination. Here, we analyzed the spatio-temporal risk of the contact between humans and the sympatric An. funestus and both M and S molecular forms of An. gambiae s.s. in an area of Benin with high coverage of vector control measures with an unprecedented level of resolution. Methods Presence-absence data for the three vectors from 1-year human-landing collections in 19 villages were assessed using binomial mixed-effects models according to vector control measures and environmental covariates derived from field and remote sensing data. After 8-fold cross-validations of the models, predictive maps of the risk of the contact between humans and the sympatric An. funestus and both molecular M and S forms of An. gambiae s.s. were computed. Results Model validations showed that the An. funestus, An. gambiae M form, and S form models provided an excellent (Area Under Curve>0.9), a good (AUC>0.8), and an acceptable (AUC>0.7) level of prediction, respectively. The distribution area of the probability of contact between human and An. funestus largely overlaps that of An. gambiae M form but this latter showed important seasonal variation. An. gambiae S form also showed seasonal variation but with different ecological preferences. Landscape data were useful to discriminate between the species’ distributions. Conclusions These results showed that available remote sensing data could help in predicting the human-vector contact for several species of malaria vectors at a village level scale. The predictive maps showed seasonal and spatial variations in the risk of human-vector contact for all three vectors. Such maps could help Malaria Control Programmes to implement more effective vector control strategy by taking into account to the dynamics of malaria vector species.
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