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Muzarabani KC, Carolus H, Schols R, Hammoud C, Barson M, Huyse T. An update on snail and trematode communities in the Sanyati Basin of Lake Kariba: New snail and trematode species but no human schistosomes. Parasitol Int 2024; 99:102830. [PMID: 38016629 DOI: 10.1016/j.parint.2023.102830] [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: 07/05/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 11/30/2023]
Abstract
BACKGROUND The construction of Lake Kariba brought about a rise in the incidence of schistosomiasis in its surrounding towns of Kariba (Zimbabwe) and Siavonga (Zambia). After extensive control programs in Kariba, schistosomiasis prevalence dropped significantly. The objective of this study was to revisit the same localities sampled by Chimbari et al. (2003), and provide an update on the snail community and prevalence of trematodes in the Northern shore of Lake Kariba while focusing on planorbid species. METHODS Monthly sampling of snails at 16 sites along the Northern shoreline of Lake Kariba, near Kariba town, was undertaken for one year. Minimum one specimen per morphotype was identified using molecular barcoding (sequencing a fragment of cytochrome c oxidase I subunit (COI)). The infection status of snails was assessed by Rapid Diagnostic PCRs (RD-PCR), and trematode infections were genotyped by sequencing COI and 18S rDNA markers. RESULTS We collected and identified seven snail species: Bulinus truncatus, Bulinus forskalii, Gyraulus sp., Physella acuta, Bellamya sp., Radix affinis plicatula and Pseudosuccinea columella. Physella acuta was the most abundant snail species (comprising 56.95% of the total snail count) and present at all sites. The B. truncatus population was found to be infected with the stomach fluke Carmyerius cruciformis, a Petasiger sp. and a trematode species belonging to the family Notocotylidae. No Schistosoma sp. infections were detected in our collected snail specimens. CONCLUSIONS We report B. truncatus as an intermediate snail host for Carmyerius cruciformis, and the presence of three non-schistosome trematode species that have not been reported in Lake Kariba before. Furthermore, we detect a possible shift in the snail community when compared to the report by Chimbari et al. (2003): this is the first record of Gyraulus sp. in Lake Kariba, and we did not observe the previously reported B. pfeifferi, B. globosus and Radix natalensis. Although this shift in snail communities might have contributed to the absence of Schistosoma spp. detection in this study, further monitoring of final and intermediate hosts across the Kariba basin is essential to prove a decrease of schistosomiasis in the area.
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Affiliation(s)
- Kudzai C Muzarabani
- Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe.
| | - Hans Carolus
- Laboratory of Molecular Cell Biology, KU Leuven, Leuven, Belgium
| | - Ruben Schols
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium; Laboratory of Aquatic Biology, KU Leuven Kulak, Kortrijk, Belgium
| | - Cyril Hammoud
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium; Limnology Research Unit, Ghent University, Ghent, Belgium
| | - Maxwell Barson
- Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe; Department of Biological Sciences, University of Botswana, Gaborone, Botswana
| | - Tine Huyse
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
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Felmy A, Streiff AB, Jokela J. Propensity for selfing varies within a population of hermaphroditic snails: coexistence of selfers, outcrossers and mixed-mating individuals. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230532. [PMID: 37800152 PMCID: PMC10548103 DOI: 10.1098/rsos.230532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 09/05/2023] [Indexed: 10/07/2023]
Abstract
To understand mating-system evolution in self-compatible hermaphrodites, variation in selfing rates is highly relevant. Empirical studies are rarely designed to capture variation between individuals, instead often comparing species and populations. Yet, evolution primarily occurs within populations, rendering among-individual variation essential. Observed individual selfing rates depend on the environment (e.g. differences in mate availability) and individuals' propensity for selfing. We quantified individual variation in selfing propensity in the snail Radix balthica by conducting laboratory mating trials that manipulated mate availability (low versus moderate) and estimating selfing rates from progeny arrays. We also measured female lifetime fitness. We found substantial among-individual variation in selfing propensity, including pure selfers (32%), pure outcrossers (31%) and mixed-mating individuals that selfed and outcrossed (37%). Experimental levels of mate availability did not significantly affect selfing rates. Selfers had reduced female liftetime fitness. Our results show that the propensity for selfing can differ considerably among individuals, with similar proportions of selfers, outcrossers and mixed maters. As mate availability did not affect selfing, our 'moderate' experimental level of mate availability might still have been too low to prompt selfers to outcross. This and the observed fitness differences also cautiously suggest that investigating the heritability of selfing propensities might be worthwhile in this population.
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Affiliation(s)
- Anja Felmy
- Department of Biology, Aquatic Ecology Unit, Lund University, 22362 Lund, Sweden
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, 8092 Zürich, Switzerland
| | - Alena B. Streiff
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, 8092 Zürich, Switzerland
| | - Jukka Jokela
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, 8092 Zürich, Switzerland
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Enabulele EE, Lawton SP, Walker AJ, Kirk RS. Molecular epidemiological analyses reveal extensive connectivity between Echinostoma revolutum (sensu stricto) populations across Eurasia and species richness of zoonotic echinostomatids in England. PLoS One 2023; 18:e0270672. [PMID: 36745633 PMCID: PMC9901765 DOI: 10.1371/journal.pone.0270672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 06/14/2022] [Indexed: 02/07/2023] Open
Abstract
Echinostoma revolutum (sensu stricto) is a widely distributed member of the Echinostomatidae, a cosmopolitan family of digenetic trematodes with complex life cycles involving a wide range of definitive hosts, particularly aquatic birds. Integrative taxonomic studies, notably those utilising nad1 barcoding, have been essential in discrimination of E. revolutum (s.s.) within the 'Echinostoma revolutum' species complex and investigation of its molecular diversity. No studies, however, have focussed on factors affecting population genetic structure and connectivity of E. revolutum (s.s.) in Eurasia. Here, we used morphology combined with nad1 and cox1 barcoding to determine the occurrence of E. revolutum (s.s.) and its lymnaeid hosts in England for the first time, in addition to other echinostomatid species Echinoparyphium aconiatum, Echinoparyphium recurvatum and Hypoderaeum conoideum. Analysis of genetic diversity in E. revolutum (s.s.) populations across Eurasia demonstrated haplotype sharing and gene flow, probably facilitated by migratory bird hosts. Neutrality and mismatch distribution analyses support possible recent demographic expansion of the Asian population of E. revolutum (s.s.) (nad1 sequences from Bangladesh and Thailand) and stability in European (nad1 sequences from this study, Iceland and continental Europe) and Eurasian (combined data sets from Europe and Asia) populations with evidence of sub-population structure and selection processes. This study provides new molecular evidence for a panmictic population of E. revolutum (s.s.) in Eurasia and phylogeographically expands the nad1 database for identification of echinostomatids.
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Affiliation(s)
- Egie E. Enabulele
- Molecular Parasitology Laboratory, School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, Surrey, United Kingdom
| | - Scott P. Lawton
- Molecular Parasitology Laboratory, School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, Surrey, United Kingdom
- Epidemiology Research Unit, Department of Veterinary and Animal Sciences, Northern Faculty, Scotland’s Rural College, Inverness, United Kingdom
| | - Anthony J. Walker
- Molecular Parasitology Laboratory, School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, Surrey, United Kingdom
| | - Ruth S. Kirk
- Molecular Parasitology Laboratory, School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, Surrey, United Kingdom
- * E-mail:
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Juhász A, Stothard JR. The giant liver fluke in Europe: A review of Fascioloides magna within cervids and livestock with considerations on an expanding snail-fluke transmission risk. ADVANCES IN PARASITOLOGY 2023; 119:223-257. [PMID: 36707174 DOI: 10.1016/bs.apar.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The giant liver fluke, Fascioloides magna, common in North America and introduced into Europe in the 19th century, is an underappreciated model system for epidemiological studies on biological invasions, interactions with other native parasites and for health impact assessments within both definitive and intermediate snail host populations. Owing to its first contemporary appearance in Europe and then its subsequent spread, fascioloidosis has become a fluke-livestock/wildlife-snail combination of increasing interest for veterinarians, parasitologists and population geneticists. Here, we present a description of its recent epidemiology, biogeography and biology, inclusive of host species lists. Special emphasis is placed upon known definitive hosts of F. magna within Europe and considerations upon this fluke's local intermediate snail hosts. This helps us envisage plausible future epidemiological scenarios for further expansion across Europe, potentially even invasion into the UK. In line with others who draw attention upon needs for better systematic monitoring of putative risk-areas of fluke transmission, we close by highlighting why better surveillance of F. magna across continental Europe, and neighbouring territories, is justified.
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Affiliation(s)
- Alexandra Juhász
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary.
| | - J Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Ahmad AA, Ramadan HKA, Hassan WA, Hakami MA, Huseein EAM, Mohamed SAA, Mohamed AA, Elossily NA. New perspectives for fascioliasis in Upper Egypt's new endemic region: Sociodemographic characteristics and phylogenetic analysis of Fasciola in humans, animals, and lymnaeid vectors. PLoS Negl Trop Dis 2022; 16:e0011000. [PMID: 36576925 PMCID: PMC9797099 DOI: 10.1371/journal.pntd.0011000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 12/01/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Fascioliasis is a significant vector-borne disease that has emerged in numerous tropical and subtropical countries causing severe health problems. Egypt is one of the fascioliasis endemic regions; however, the current situation in Upper Egypt is understudied, with only sporadic human cases or outbreaks. This study aims to highlight the sociodemographic characteristics of human fascioliasis in a newly emerged endemic area in Upper Egypt, along with risk factors analysis and the molecular characteristics of the fasciolid population in humans, animals, and lymnaeid snails. METHODOLOGY/PRINCIPAL FINDINGS The study reported Fasciola infection in patients and their close relatives by analyzing the risk of human infection. Morphological and molecular characterization was performed on lymnaeid snails. Multigene sequencing was also used to characterize fasciolids from human cases, cattle, and pooled snail samples. The study identified asymptomatic Fasciola infection among family members and identified the presence of peridomestic animals as a significant risk factor for infection. This is the first genetic evidence that Radix auricularia exists as the snail intermediate host in Egypt. CONCLUSIONS/SIGNIFICANCE This study revealed that Assiut Governorate in Upper Egypt is a high-risk area for human fascioliasis that requires additional control measures. Fasciola hepatica was the main causative agent infecting humans and snail vectors in this newly emerged endemic area. In addition, this is the first report of R. auricularia as the snail intermediate host transmitting fascioliasis in Upper Egypt. Further research is required to clarify the widespread distribution of Fasciola in Egypt's various animal hosts. This provides insight into the mode of transmission, epidemiological criteria, and genetic diversity of fasciolid populations in Upper Egypt.\.
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Affiliation(s)
| | | | - Waleed Attia Hassan
- Faculty of Medicine, Department of Tropical Medicine and Gastroenterology, Assiut University, Egypt
| | - Mohammed Ageeli Hakami
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Al-Quwayiyah, Shaqra University, Riyadh, Saudi Arabia
| | | | - Sara Abdel-Aal Mohamed
- Faculty of Veterinary medicine, Department of Parasitology, Assiut University, Assiut, Egypt
| | - Adnan Ahmed Mohamed
- Faculty of Medicine, Department of Tropical Medicine and Gastroenterology, Assiut University, Egypt
| | - Nahed Ahmed Elossily
- Faculty of Medicine, Department of Medical Parasitology, Assiut University, Assiut, Egypt
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Schols R, Carolus H, Hammoud C, Muzarabani KC, Barson M, Huyse T. Invasive snails, parasite spillback, and potential parasite spillover drive parasitic diseases of Hippopotamus amphibius in artificial lakes of Zimbabwe. BMC Biol 2021; 19:160. [PMID: 34412627 PMCID: PMC8377832 DOI: 10.1186/s12915-021-01093-2] [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: 01/28/2021] [Accepted: 07/12/2021] [Indexed: 11/25/2022] Open
Abstract
Background Humans impose a significant pressure on large herbivore populations, such as hippopotami, through hunting, poaching, and habitat destruction. Anthropogenic pressures can also occur indirectly, such as artificial lake creation and the subsequent introduction of invasive species that alter the ecosystem. These events can lead to drastic changes in parasite diversity and transmission, but generally receive little scientific attention. Results In order to document and identify trematode parasites of the common hippopotamus (Hippopotamus amphibius) in artificial water systems of Zimbabwe, we applied an integrative taxonomic approach, combining molecular diagnostics and morphometrics on archived and new samples. In doing so, we provide DNA reference sequences of the hippopotamus liver fluke Fasciola nyanzae, enabling us to construct the first complete Fasciola phylogeny. We describe parasite spillback of F. nyanzae by the invasive freshwater snail Pseudosuccinea columella, as a consequence of a cascade of biological invasions in Lake Kariba, one of the biggest artificial lakes in the world. Additionally, we report an unknown stomach fluke of the hippopotamus transmitted by the non-endemic snail Radix aff. plicatula, an Asian snail species that has not been found in Africa before, and the stomach fluke Carmyerius cruciformis transmitted by the native snail Bulinus truncatus. Finally, Biomphalaria pfeifferi and two Bulinus species were found as new snail hosts for the poorly documented hippopotamus blood fluke Schistosoma edwardiense. Conclusions Our findings indicate that artificial lakes are breeding grounds for endemic and non-endemic snails that transmit trematode parasites of the common hippopotamus. This has important implications, as existing research links trematode parasite infections combined with other stressors to declining wild herbivore populations. Therefore, we argue that monitoring the anthropogenic impact on parasite transmission should become an integral part of wildlife conservation efforts. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01093-2.
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Affiliation(s)
- Ruben Schols
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium. .,Laboratory of Aquatic Biology, KU Leuven Kulak, Kortrijk, Belgium.
| | - Hans Carolus
- Laboratory of Molecular Cell Biology, KU Leuven-VIB Center for Microbiology, Leuven, Belgium
| | - Cyril Hammoud
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium.,Limnology Research Unit, Ghent University, Ghent, Belgium
| | | | - Maxwell Barson
- Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe.,Department of Biological Sciences, University of Botswana, Gaborone, Botswana.,Lake Kariba Research Station, University of Zimbabwe, Kariba, Zimbabwe
| | - Tine Huyse
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
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Pantoja C, Faltýnková A, O'Dwyer K, Jouet D, Skírnisson K, Kudlai O. Diversity of echinostomes (Digenea: Echinostomatidae) in their snail hosts at high latitudes. ACTA ACUST UNITED AC 2021; 28:59. [PMID: 34319230 PMCID: PMC8336728 DOI: 10.1051/parasite/2021054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/24/2021] [Indexed: 11/14/2022]
Abstract
The biodiversity of freshwater ecosystems globally still leaves much to be discovered, not least in the trematode parasite fauna they support. Echinostome trematode parasites have complex, multiple-host life-cycles, often involving migratory bird definitive hosts, thus leading to widespread distributions. Here, we examined the echinostome diversity in freshwater ecosystems at high latitude locations in Iceland, Finland, Ireland and Alaska (USA). We report 14 echinostome species identified morphologically and molecularly from analyses of nad1 and 28S rDNA sequence data. We found echinostomes parasitising snails of 11 species from the families Lymnaeidae, Planorbidae, Physidae and Valvatidae. The number of echinostome species in different hosts did not vary greatly and ranged from one to three species. Of these 14 trematode species, we discovered four species (Echinoparyphium sp. 1, Echinoparyphium sp. 2, Neopetasiger sp. 5, and Echinostomatidae gen. sp.) as novel in Europe; we provide descriptions for the newly recorded species and those not previously associated with DNA sequences. Two species from Iceland (Neopetasiger islandicus and Echinoparyphium sp. 2) were recorded in both Iceland and North America. All species found in Ireland are new records for this country. Via an integrative taxonomic approach taken, both morphological and molecular data are provided for comparison with future studies to elucidate many of the unknown parasite life cycles and transmission routes. Our reports of species distributions spanning Europe and North America highlight the need for parasite biodiversity assessments across large geographical areas.
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Affiliation(s)
- Camila Pantoja
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic - Institute of Ecology, Nature Research Centre, Akademijos 2, 08412 Vilnius, Lithuania
| | - Anna Faltýnková
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Katie O'Dwyer
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, H91 T8NW Galway, Ireland
| | - Damien Jouet
- BioSpecT EA7506, Faculty of Pharmacy, University of Reims Champagne-Ardenne, 51 rue Cognacq-Jay, 51096 Reims Cedex, France
| | - Karl Skírnisson
- Laboratory of Parasitology, Institute for Experimental Pathology, Keldur, University of Iceland, IS-112 Reykjavík, Iceland
| | - Olena Kudlai
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic - Institute of Ecology, Nature Research Centre, Akademijos 2, 08412 Vilnius, Lithuania
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Mirfendereski R, Hashemi S, Shirali S, Shemshadi B, Lawton SP. DNA barcoding of Iranian radicine freshwater snails begins to untangle the taxonomy and phylogeography of intermediate hosts of schistosomiasis and fasciolosis from the Middle East and across Central Asia. INFECTION GENETICS AND EVOLUTION 2021; 89:104728. [PMID: 33497838 DOI: 10.1016/j.meegid.2021.104728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 11/29/2022]
Abstract
In the Middle East radicine snails are of considerable medical and veterinary importance acting as vectors of trematodes. In Iran, such snails are responsible for the transmission of the zoonotic trematodes Schistosoma turkestanicum and Fasciola gigantica. Historically, Radix gedrosiana has been incriminated as an important intermediate host for both trematodes, however, controversy remains over the snail's true taxonomic status. This species has been determined using morphological characters that has resulted in erroneous identification of species, affecting understanding of population biology, and ultimately affecting vector incrimination. In this current study DNA barcoding using cox1 and phylogenetic analyses revealed that snails identified as R. gedrosiana from Iran split into two separate species, Radix euphratica and Ampullaceana sp. The cox1 also provided useful insights into the evolutionary history of R. euphratica populations. Phylogeographic analyses indicated that R. euphratica had an Iraqi/Iranian origin approximately 3.3 MYA and exists as a large stable population across the Middle East and Central Asia, and a lack of genetic differentiation between geographical isolates. Such molecular barcoding techniques are crucial for the identification of radicine snails of Iran being invaluable for the monitoring of zoonotic flukes, understanding the distribution of infection and the accurate incrimination of snail vectors.
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Affiliation(s)
- Ramtin Mirfendereski
- Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran, Iran; Molecular Parasitology Laboratory, School of Life Sciences, Pharmacy and Chemistry, Kingston University London, Penrhyn Road, Kingston Upon Thames, Surrey, United Kingdom
| | - Saeid Hashemi
- Department of Parasitology, Borujerd Branch Islamic Azad University, Borujerd, Iran
| | - Salome Shirali
- Department of Biotechnology, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
| | - Bahar Shemshadi
- Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
| | - Scott P Lawton
- Epidemiology Research Unit (ERU) Department of Veterinary and Animal Sciences, Northern Faculty, Scotland's Rural College (SRUC), An Lòchran, 10 Inverness Campus, Inverness, IV2 5NA, United Kingdom.
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Ashrafi K, Sharifdini M, Darjani A, Brant SV. Migratory routes, domesticated birds and cercarial dermatitis: the distribution of Trichobilharzia franki in Northern Iran. ACTA ACUST UNITED AC 2021; 28:4. [PMID: 33433322 PMCID: PMC7802520 DOI: 10.1051/parasite/2020073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 12/11/2020] [Indexed: 11/21/2022]
Abstract
Background: One of the major migration routes for birds going between Europe and Asia is the Black Sea-Mediterranean route that converges on the Volga Delta, continuing into the area of the Caspian Sea. Cercarial dermatitis is a disorder in humans caused by schistosome trematodes that use aquatic birds and snails as hosts and is prevalent in areas of aquaculture in Northern Iran. Before the disorder can be addressed, it is necessary to determine the etiological agents and their host species. This study aimed to document whether domestic mallards are reservoir hosts and if so, to characterize the species of schistosomes. Previous work has shown that domestic mallards are reservoir hosts for a nasal schistosome. Results: In 32 of 45 domestic mallards (Anas platyrhynchos domesticus) (71.1%), the schistosome Trichobilharzia franki, previously reported only from Europe, was found in visceral veins. Morphological and molecular phylogenetic analysis confirmed the species designation. These findings extend the range of T. franki from Europe to Eurasia. Conclusion: The occurrence of cercarial dermatitis in Iran is high in areas of aquaculture. Previous studies in the area have shown that domestic mallards are reservoir hosts of T. regenti, a nasal schistosome and T. franki, as shown in this study. The genetic results support the conclusion that populations of T. franki from Iran are not differentiated from populations in Europe. Therefore, the schistosomes are distributed with their migratory duck hosts, maintaining the gene flow across populations with compatible snail hosts in Iran.
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Affiliation(s)
- Keyhan Ashrafi
- Department of Medical Parasitology and Mycology, School of Medicine, Guilan University of Medical Sciences, Rasht 41996-13776, Iran
| | - Meysam Sharifdini
- Department of Medical Parasitology and Mycology, School of Medicine, Guilan University of Medical Sciences, Rasht 41996-13776, Iran
| | - Abbas Darjani
- Skin Research Center, Department of Dermatology, Razi Hospital, Guilan University of Medical Sciences, Rasht 41996-13776, Iran
| | - Sara V Brant
- Museum of Southwestern Biology, Division of Parasites, Department of Biology, University of New Mexico, 1 University of New Mexico MSC03 2020, Albuquerque, New Mexico 87131, USA
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Schols R, Mudavanhu A, Carolus H, Hammoud C, Muzarabani KC, Barson M, Huyse T. Exposing the Barcoding Void: An Integrative Approach to Study Snail-Borne Parasites in a One Health Context. Front Vet Sci 2020; 7:605280. [PMID: 33363243 PMCID: PMC7758321 DOI: 10.3389/fvets.2020.605280] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/16/2020] [Indexed: 11/13/2022] Open
Abstract
Trematodes are snail-borne parasites of major zoonotic importance that infect millions of people and animals worldwide and frequently hybridize with closely related species. Therefore, it is desirable to study trematodiases in a One Health framework, where human and animal trematodes are considered equally important. It is within this framework that we set out to study the snail and trematode communities in four artificial lakes and an abattoir in Zimbabwe. Trematode infections in snails were detected through multiplex PCR protocols. Subsequently, we identified snails by sequencing a partial mitochondrial cytochrome c oxidase subunit I (COI) fragment, and trematodes (adults from the abattoir and larval stages detected in snails) using COI and nuclear rDNA markers. Of the 1,674 collected snails, 699 were molecularly analyzed, in which we identified 12 snail and 19 trematode species. Additionally, three parasite species were sampled from the abattoir. Merely four trematode species were identified to species level through COI-based barcoding. Moreover, identification of members of the superfamilies Opisthorchioidea and Plagiorchioidea required a phylogenetic inference using the highly conserved 18S rDNA marker, as no related COI reference sequences were present in public databases. These barcoding challenges demonstrate a severe barcoding void in the available databases, which can be attributed to the neglected status of trematodiases. Adding to this, many available sequences cannot be used as different studies use different markers. To fill this gap, more studies on African trematodes, using a standardized COI barcoding region, are desperately needed.
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Affiliation(s)
- Ruben Schols
- Laboratory of Aquatic Biology, Katholieke Universiteit Leuven Kulak, Kortrijk, Belgium.,Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
| | - Aspire Mudavanhu
- Department of Biological Sciences, Bindura University of Science Education, Bindura, Zimbabwe
| | - Hans Carolus
- Laboratory of Molecular Cell Biology, Katholieke Universiteit Leuven-Vlaams Instituut voor Biotechnologie Center for Microbiology, Leuven, Belgium
| | - Cyril Hammoud
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium.,Limnology Research Unit, Ghent University, Ghent, Belgium
| | | | - Maxwell Barson
- Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe.,Department of Biological Sciences, University of Botswana, Gaborone, Botswana
| | - Tine Huyse
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
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Species-specific patterns in cercarial emergence of Diplostomum spp. from snails Radix lagotis. Int J Parasitol 2020; 50:1177-1188. [PMID: 32896571 DOI: 10.1016/j.ijpara.2020.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 07/07/2020] [Accepted: 07/12/2020] [Indexed: 11/21/2022]
Abstract
The cercarial emergence patterns of three species of Diplostomum (Diplostomum 'mergi', Diplostomum spathaceum and Diplostomum parviventosum) parasitizing freshwater first intermediate host Radix lagotis sampled in Most Lake, Czech Republic, were studied under various experimental conditions, i.e. field, laboratory and incubator, and seasons, i.e. spring, summer and autumn. We discovered unexpected daily periodicity-dependent species-specific emergence patterns among the three Diplostomum spp. depending on experimental conditions. At the same time, the intraspecific variation of D. spathaceum cercarial release in response to seasonal conditions was observed. We found that a complex array of mechanisms can affect Diplostomum species-specific patterns in cercarial emergence, of which behavioural characteristics of fish related to reproduction and feeding processes are considered the most important factors. This might represent a specific adaptive evolutionary mechanism to maximise transmission success while avoiding competition for host resources. Our results contribute to a better understanding of ecological and epidemiological aspects with respect to specific adaptive strategies compartmentalised among species of Diplostomum and consequences for infection risk in fish hosts.
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12
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Felmy A, Weissert N, Travis J, Jokela J. Mate availability determines use of alternative reproductive phenotypes in hermaphrodites. Behav Ecol 2020. [DOI: 10.1093/beheco/araa046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
In many species, individuals can employ alternative reproductive phenotypes, with profound consequences for individual fitness and population dynamics. This is particularly relevant for self-compatible hermaphrodites, which have exceptionally many reproductive options. Here we investigated the occurrence of reproductive phenotypes in the simultaneously hermaphroditic freshwater snail Radix balthica under experimentally simulated conditions of low versus moderate population density. We captured all mating behavior on camera and measured individual female lifetime reproductive success. We found every possible reproductive phenotype: (1) both male and female (i.e., truly hermaphroditic) reproduction, (2) purely female and (3) purely male reproduction, (4) male reproduction combined with self-fertilization and (5) female mating activity, (6) pure self-fertilization without mating and (7–8) two types of reproductive failure. Variation in alternative reproductive phenotypes was explained by mate availability (10.8%) and individual condition, approximated by a snail’s mean daily growth rate (17.5%). Increased mate availability resulted in a lower diversity of reproductive phenotypes, in particular increasing the frequency of true hermaphrodites. However, it lowered phenotype-specific fecundities and hence reduced the population growth rate. Snails in better condition were more likely to reproduce as true hermaphrodites or pure females, whereas low-condition snails tended to suffer reproductive failure. Overall, we show substantial variation in alternative reproductive phenotypes in a hermaphrodite, which is possibly in part maintained by fluctuations in population density and thus mate availability, and by variation in individual condition. We also provide evidence of an almost 2-fold increase in clutch size that can be ascribed specifically to mating as a female.
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Affiliation(s)
- Anja Felmy
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, Universitätstrasse 16, Zurich, Switzerland
- Department of Zoology, University of Oxford, Oxford, UK
| | - Nora Weissert
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, Dübendorf, Switzerland
| | - Joseph Travis
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Jukka Jokela
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, Dübendorf, Switzerland
- ETH Zurich, D-USYS, Institute of Integrative Biology, Universitätstrasse 16, Zurich, Switzerland
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13
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Selbach C, Soldánová M, Feld CK, Kostadinova A, Sures B. Hidden parasite diversity in a European freshwater system. Sci Rep 2020; 10:2694. [PMID: 32060320 PMCID: PMC7021786 DOI: 10.1038/s41598-020-59548-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 01/30/2020] [Indexed: 02/05/2023] Open
Abstract
Parasites comprise a huge part of the biodiversity on earth. However, on a local scale, not much is known about their diversity and community structure. Here, we assess the diversity of larval trematode communities in an interconnected freshwater system of the River Ruhr in Germany and analyse how the parasites are spatially and temporally distributed in the ecosystem. A total of 5347 snail hosts belonging to six species revealed a highly diverse parasite fauna with 36 trematode species. More abundant snail species harboured more species-rich trematode faunas and communities, with the two dominant snail species, Radix auricularia and Gyraulus albus, accounting for almost 90% of the trematode diversity and harbouring spatially and temporally stable parasite communities. The results highlight the important role of stable keystone host populations for trematode transmission, structure and diversity. This local trematode diversity reveals information on definitive host occurrence and trophic interactions within ecosystems.
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Affiliation(s)
- Christian Selbach
- Department of Aquatic Ecology, University of Duisburg-Essen, 45141, Essen, Germany.,Department of Biology, Aquatic Biology, Aarhus University, 8000, Aarhus C, Denmark
| | - Miroslava Soldánová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 37005, České Budějovice, Czech Republic
| | - Christian K Feld
- Department of Aquatic Ecology, University of Duisburg-Essen, 45141, Essen, Germany
| | - Aneta Kostadinova
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113, Sofia, Bulgaria
| | - Bernd Sures
- Department of Aquatic Ecology, University of Duisburg-Essen, 45141, Essen, Germany. .,Department of Zoology, University of Johannesburg, Johannesburg, South Africa.
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Qin DM, Huang XC, Yang LM, Liu XJ, Wu RW, Ouyang S, Wu XP, Wang SH. Complete mitochondrial genome of the radicine pond snail Radix plicatula (Gastropoda: Lymnaeidae). MITOCHONDRIAL DNA PART B-RESOURCES 2019; 4:2861-2862. [PMID: 33365763 PMCID: PMC7706513 DOI: 10.1080/23802359.2019.1661300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Radix plicatula is broadly distributed in China, as well as Russia. It is one of the intermediate hosts of Fasciola species which leads to the spread of fascioliasis. Here, we first described the complete mitochondrial genome of R. plicatula. The mitogenome is 13,751 bp in length, containing 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes. The contents of each base are 30.7% A, 39.6% T, 15.7% G, and 13.9% C. The sequence is AT rich (70.3%). Mitochondrial phylogenomic analysis showed that R. plicatula is close to R. auricularia.
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Affiliation(s)
- Dong-Mei Qin
- School of Life Sciences, Nanchang University, Nanchang, People's Republic of China
| | - Xiao-Chen Huang
- School of Life Sciences, Nanchang University, Nanchang, People's Republic of China
| | - Li-Min Yang
- School of Life Sciences, Nanchang University, Nanchang, People's Republic of China
| | - Xiong-Jun Liu
- Poyang Lake Key Laboratory of Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, People's Republic of China
| | - Rui-Wen Wu
- School of Life Sciences, Nanchang University, Nanchang, People's Republic of China
| | - Shan Ouyang
- School of Life Sciences, Nanchang University, Nanchang, People's Republic of China
| | - Xiao-Ping Wu
- School of Life Sciences, Nanchang University, Nanchang, People's Republic of China.,Poyang Lake Key Laboratory of Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, People's Republic of China.,School of Resource, Environment and Chemical Engineering, Nanchang University, Nanchang, People's Republic of China
| | - Shang-Hong Wang
- School of Life Sciences, Nanchang University, Nanchang, People's Republic of China
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Carolus H, Muzarabani KC, Hammoud C, Schols R, Volckaert FAM, Barson M, Huyse T. A cascade of biological invasions and parasite spillback in man-made Lake Kariba. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 659:1283-1292. [PMID: 31096340 DOI: 10.1016/j.scitotenv.2018.12.307] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
Parasite spillback, the infection of a non-indigenous organism by a native parasite, is a highly important although understudied component of ecological invasion dynamics. Here, through the first analysis of the parasite fauna of lymnaeid gastropods of Lake Kariba (Zimbabwe). We illustrate how the creation of an artificial lake may lead to a cascade of biological invasions in which an invasive aquatic plant promotes the proliferation of invasive gastropods, which in turn alters the epidemiology of trematodiases of potential medical and veterinary importance. Using a new multiplex Rapid Diagnostic PCR assay, we assessed the prevalence of Fasciola sp. infections in the gastropod populations. Both gastropod hosts and trematode parasites were identified using DNA barcoding. We provide the first record of the invasive North-American gastropod Pseudosuccinea columella in Lake Kariba. This species was found at 14 out of 16 sampled sites and its abundance was strongly positively correlated with the abundance of the invasive South-American water hyacinth (Eichhornia crassipes). About 65% of the P. columella specimens analysed were infected with a hitherto unknown Fasciola species. Phylogenetic analyses indicate close affinity to Fasciola hepatica and F. gigantica, which cause fasciolosis, an important liver disease affecting both ruminants and humans. In addition, another non-native Lymnaeid species was found: a Radix sp. that clustered closely with a Vietnamese Radix species. Radix sp. hosted both amphistome and Fasciola trematodes. By linking an invasion cascade and parasite spillback, this study shows how both processes can act in combination to lead to potentially important epidemiological changes.
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Affiliation(s)
- Hans Carolus
- Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven, Leuven, Belgium; Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
| | | | - Cyril Hammoud
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
| | - Ruben Schols
- Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
| | - Filip A M Volckaert
- Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven, Leuven, Belgium
| | - Maxwell Barson
- Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe
| | - Tine Huyse
- Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven, Leuven, Belgium; Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium.
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Lawton SP, Allan F, Hayes PM, Smit NJ. DNA barcoding of the medically important freshwater snail Physa acuta reveals multiple invasion events into Africa. Acta Trop 2018; 188:86-92. [PMID: 30165073 DOI: 10.1016/j.actatropica.2018.08.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 07/22/2018] [Accepted: 08/24/2018] [Indexed: 01/15/2023]
Abstract
The medically important freshwater snail Physa acuta is highly invasive and has been reported in several freshwater environments across Africa. To identify species and provide initial insights into the origins of P. acuta into African freshwater environments standard molecular barcoding analyses, using the mitochondrial cytochrome c oxidase subunit I gene (COI), was performed on P. acuta isolates from Angola, Burundi and South Africa. Phylogenetic analyses of isolates from Africa could not be distinguished from P. acuta populations from other countries. Comparisons of COI sequences between isolates of P. acuta showed there to be no geographically specific clusters and the African isolates were distributed across four distinct unrelated clades suggesting several independent invasion events. Haplotype analyses indicated that there were a high number of haplotypes with low variation between them, which led to significant differences in AMOVA analyses between countries. This was further evidence of multiple invasion events suggesting multiple novel haplotypes being continually and independently introduced to each country. This approach not only provides initial insight into the invasion of Africa by P. acuta but a molecular method to monitor and manage the use of an agent of biological control.
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Molecular and morphological characterization of the cercariae of Lecithodendrium linstowi (Dollfus, 1931), a trematode of bats, and incrimination of the first intermediate snail host, Radix balthica. Parasitology 2017; 145:307-312. [PMID: 29113594 DOI: 10.1017/s0031182017001640] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Lecithodendrium linstowi is one of the most prevalent and abundant trematodes of bats, but the larval stages and intermediate hosts have not been identified. We present the first molecular and morphological characterization of the cercariae of L. linstowi based on a phylogenetic analysis of partial fragments of LSU and ITS2 rDNA. The first intermediate host was incriminated as Radix balthica by DNA barcoding using cox1 and ITS2 sequences, although the snail morphologically resembled Radix peregra, emphasizing the requirement for molecular identification of lymnaeids as important intermediate hosts of medical and veterinary impact. The application of molecular data in this study has enabled linkage of life cycle stages and accurate incrimination of the first intermediate host.
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Aksenova O, Vinarski M, Bolotov I, Kondakov A, Bespalaya Y, Tomilova A, Paltser I, Gofarov M. Two Radix
spp. (Gastropoda: Lymnaeidae) endemic to thermal springs around Lake Baikal represent ecotypes of the widespread Radix auricularia. J ZOOL SYST EVOL RES 2017. [DOI: 10.1111/jzs.12174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Olga Aksenova
- Federal Center for Integrated Arctic Research of Russian Academy of Sciences; Arkhangelsk Russia
- Northern Arctic Federal University; Arkhangelsk Russia
| | - Maxim Vinarski
- Saint Petersburg State University; Saint Petersburg Russia
- Museum of Siberian Aquatic Molluscs; Omsk State Pedagogical University; Omsk Russia
| | - Ivan Bolotov
- Federal Center for Integrated Arctic Research of Russian Academy of Sciences; Arkhangelsk Russia
- Northern Arctic Federal University; Arkhangelsk Russia
| | - Alexander Kondakov
- Federal Center for Integrated Arctic Research of Russian Academy of Sciences; Arkhangelsk Russia
- Northern Arctic Federal University; Arkhangelsk Russia
| | - Yulia Bespalaya
- Federal Center for Integrated Arctic Research of Russian Academy of Sciences; Arkhangelsk Russia
- Northern Arctic Federal University; Arkhangelsk Russia
| | - Alyona Tomilova
- Federal Center for Integrated Arctic Research of Russian Academy of Sciences; Arkhangelsk Russia
- Northern Arctic Federal University; Arkhangelsk Russia
| | - Inga Paltser
- Federal Center for Integrated Arctic Research of Russian Academy of Sciences; Arkhangelsk Russia
| | - Mikhail Gofarov
- Federal Center for Integrated Arctic Research of Russian Academy of Sciences; Arkhangelsk Russia
- Northern Arctic Federal University; Arkhangelsk Russia
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Bürkli A, Jokela J. Increase in multiple paternity across the reproductive lifespan in a sperm-storing, hermaphroditic freshwater snail. Mol Ecol 2017; 26:5264-5278. [PMID: 28605149 DOI: 10.1111/mec.14200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 06/01/2017] [Accepted: 06/02/2017] [Indexed: 12/28/2022]
Abstract
Polyandry is a common phenomenon and challenges the traditional view of stronger sexual selection in males than in females. In simultaneous hermaphrodites, the physical proximity of both sex functions was long thought to preclude the operation of sexual selection. Laboratory studies suggest that multiple mating and polyandry in hermaphrodites may actually be common, but data from natural populations are sparse. We therefore estimated the rate of multiple paternity and its seasonal variability in the annual, sperm-storing, simultaneously hermaphroditic freshwater snail Radix balthica for the entire duration of the reproductive lifespan. We also tested whether multiple paternity was associated with clutch size or embryonic development. To obtain these data, we measured and genotyped 60 field-collected egg clutches using nine highly polymorphic microsatellite markers. Overall, 50% of the clutches had multiple fathers, and both the frequency (20-93% of clutches) and magnitude of multiple paternity (mean 1.3-3.8 fathers per clutch) substantially increased over time, probably because of extensive sperm storage. Most multiply sired clutches (83%) had a dominant father, but neither clutch size nor the proportion of developed embryos per clutch was associated with levels of multiple paternity. Both the evident promiscuity and the frequent skew of paternity shares suggest that sexual selection may be an important evolutionary force in the study population.
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Affiliation(s)
- Anja Bürkli
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.,ETH Zurich, D-USYS, Institute of Integrative Biology, Zürich, Switzerland
| | - Jukka Jokela
- Department of Aquatic Ecology, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.,ETH Zurich, D-USYS, Institute of Integrative Biology, Zürich, Switzerland
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20
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Molecular analyses reveal high species diversity of trematodes in a sub-Arctic lake. Int J Parasitol 2017; 47:327-345. [DOI: 10.1016/j.ijpara.2016.12.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Revised: 12/09/2016] [Accepted: 12/12/2016] [Indexed: 02/05/2023]
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21
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Comparing direct and indirect selfing rate estimates: when are population-structure estimates reliable? Heredity (Edinb) 2017; 118:525-533. [PMID: 28177324 DOI: 10.1038/hdy.2017.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 12/21/2016] [Accepted: 12/30/2016] [Indexed: 11/08/2022] Open
Abstract
The rate of self-fertilization (that is, selfing) is a key evolutionary parameter in hermaphroditic species, yet obtaining accurate estimates of selfing rates in natural populations can be technically challenging. Most published estimates are derived from population-level heterozygote deficiency (that is, FIS) or identity disequilibria (for example, the software RMES (robust multilocus estimate of selfing)). These indirect methods can be applied to population genetic survey data, whereas direct methods using progeny arrays require much larger data sets that are often difficult to collect in natural populations or even require captive breeding. Unfortunately, indirect methods rely on assumptions that can be problematic, such as negating biparental inbreeding, inbreeding disequilibrium and (for FIS) the presence of null alleles. The performance of indirect estimates against progeny-array estimates is still largely unknown. Here we used both direct progeny-array and indirect population-level methods to estimate the selfing rate in a single natural population of the simultaneously hermaphroditic freshwater snail Radix balthica throughout its reproductive lifespan using 10 highly polymorphic microsatellites. We found that even though progeny arrays (n=1034 field-collected embryos from 60 families) did not reveal a single selfed embryo, FIS-based selfing rates (n=316 adults) were significantly positive in all 6 sequential population samples. Including a locus with a high frequency of null alleles further biased FIS-based estimates. Conversely, RMES-based estimates were very similar to progeny-array estimates and proved insensitive to null alleles. The assumptions made by RMES were thus either met or irrelevant in this particular population, making RMES a valid, cost-efficient alternative to progeny arrays.
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Mu X, Yang Y, Liu Y, Luo D, Xu M, Wei H, Gu D, Song H, Hu Y. The complete mitochondrial genomes of two freshwater snails provide new protein-coding gene rearrangement models and phylogenetic implications. Parasit Vectors 2017; 10:11. [PMID: 28061879 PMCID: PMC5219674 DOI: 10.1186/s13071-016-1956-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 12/23/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mitochondrial (mt) genome sequences are widely used for species identification and to study the phylogenetic relationships among Gastropoda. However, to date, limited data are available as taxon sampling is narrow. In this study we sequenced the complete mt genomes of the freshwater gastropods Radix swinhoei (Lymnaeidae) and Planorbarius corneus (Planorbidae). Based on these sequences, we investigated the gene rearrangement in these two species and the relationships with respect to the ancestral gene order and assessed their phylogenetic relationships. METHODS The complete mt genomes of R. swinhoei and P. corneus were sequenced using Illumina-based paired-end sequencing and annotated by comparing the sequence information with that of related gastropod species. Putative models of mitochondrial gene rearrangements were predicted for both R. swinhoei and P. corneus, using Reishia clavigera mtDNA structure as the ancestral gene order. The phylogenetic relationships were inferred using thirteen protein sequences based on Maximum likelihood and Bayesian inference analyses. RESULTS The complete circular mt genome sequences of R. swinhoei and P. corneus were 14,241 bp and 13,687 bp in length, respectively. Comparison of the gene order demonstrated complex rearrangement events in Gastropoda, both for tRNA genes and protein-coding genes. The phylogenetic analyses showed that the family Lymnaeidae was more closely related to the family Planorbidae, consistent with previous classification. Nevertheless, due to the position recovered for R. swinhoei, the family Lymnaeidae was not monophyletic. CONCLUSION This study provides the complete mt genomes of two freshwater snails, which will aid the development of useful molecular markers for epidemiological, ecological and phylogenetic studies. Additionally, the predicted models for mt gene rearrangement might provide novel insights into mt genome evolution in gastropods.
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Affiliation(s)
- Xidong Mu
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Yexin Yang
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Yi Liu
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Du Luo
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Meng Xu
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Hui Wei
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Dangen Gu
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Hongmei Song
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
| | - Yinchang Hu
- Key Laboratory of Tropical&Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Xingyu Road1, Guangzhou, 510380 China
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Gordy MA, Kish L, Tarrabain M, Hanington PC. A comprehensive survey of larval digenean trematodes and their snail hosts in central Alberta, Canada. Parasitol Res 2016; 115:3867-80. [DOI: 10.1007/s00436-016-5152-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/23/2016] [Indexed: 10/21/2022]
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