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Vafopoulou X, Steel CGH. Halloween genes are expressed with a circadian rhythm during development in prothoracic glands of the insect RHODNIUS PROLIXUS. Comp Biochem Physiol A Mol Integr Physiol 2024; 290:111588. [PMID: 38242349 DOI: 10.1016/j.cbpa.2024.111588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
We analyse the developmental and circadian profiles of expression of the genes responsible for ecdysteroidogenesis (Halloween genes) in the PGs of Rhodnius prolixus throughout larval-adult development. Extensive use of in vitro techniques enabled multiple different parameters to be measured in individual PGs. Expression of disembodied and spook closely paralleled the ecdysteroid synthesis of the same PGs, and the ecdysteroid titre in vivo, but with functionally significant exceptions. Various tissues other than PGs expressed one, both or neither genes. Both gonads express both genes in pharate adults (larvae close to ecdysis). Both genes were expressed at low, but significant, levels in UF Rhodnius, raising questions concerning how developmental arrest is maintained in UF animals. IHC confirmed the subcellular localisation of the coded proteins. Gene knockdown suppressed transcription of both genes and ecdysteroid synthesis, with spook apparently regulating the downstream gene disembodied. Transcription of both genes occurred with a daily rhythm (with peaks at night) that was confirmed to be under circadian control using aperiodic conditions. The complex behaviour of the rhythm in LL implied two anatomically distinct oscillators regulate this transcription rhythm. First, the circadian clock in the PGs and second, the circadian rhythm of of Rhodnius PTTH which is released rhythmically from the brain under control of the circadian clock therein, both of which were described previously. We conclude ecdysteroidogenesis in Rhodnius PGs employs a similar pathway as other insects, but its control is complex, involving mechanisms both within and outside the PGs.
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Affiliation(s)
| | - Colin G H Steel
- Department of Biology, York University, Toronto M3J 1P3, Canada.
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2
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Saeed A, Mehmood S, Zahoor MS, Khan EU, Usman M, Hashmi SGMD, Saleem K, Ahmad S. Comparative evaluation of different moulting methods on productive performance, egg quality, and antibody response of leghorn hens. Trop Anim Health Prod 2023; 55:304. [PMID: 37728634 DOI: 10.1007/s11250-023-03710-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 09/12/2023] [Indexed: 09/21/2023]
Abstract
The aim of the study was to compare three moulting procedures and their effect on productive performance, egg quality, and antibody response of leghorn hens. For this, a total of 324 laying hens were distributed into three treatment groups having 12 replicates of 9 birds each according to completely randomized design. Treatments consisted of three moulting procedures based on feed and light restriction. The targeted weight at the end of moulting was 1450-1470 g. As soon as the moulting procedure is complete, the comparative analysis of post-moult productive performance (feed intake, egg production, egg weight, egg mass, feed per dozen eggs, feed per kg egg mass, livability), egg quality characteristics (egg weight, egg length and width, shape index, surface area, volume, albumen height, weight, Haugh unit score, yolk width, height, index, egg shell pore number, shell weight, thickness, breaking strength), and antibody response against Newcastle disease and avian influenza (H-9) were evaluated. Birds subjected to moulting procedure 3 (8 days fasting and gradual decrease in light) showed improvement in productive performance, egg geometry and quality traits, and antibody response against Newcastle disease virus. Birds experienced moulting procedure 1 (11 days fasting) had improved feed intake, egg production, and livability. However, birds moulted with procedure 2 (6 days fasting) revealed intermediate result in all the studied parameters. In conclusion, moulting through feed and light restriction with 8 days fasting and gradual reduction in light has potential to improve performance of leghorn hens.
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Affiliation(s)
- Amir Saeed
- Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Shahid Mehmood
- Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Muhammad Shahid Zahoor
- Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Ehsaan Ullah Khan
- Department of Animal Nutrition, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Muhammad Usman
- Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Syed Ghulam Mohayud Din Hashmi
- Department of Wildlife and Ecology, Faculty of Fisheries and Wildlife, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Kinza Saleem
- Department of Animal Nutrition, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Sohail Ahmad
- Department of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
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Gillingham EL, Medlock JM, Macintyre H, Phalkey R. Modelling the current and future temperature suitability of the UK for the vector Hyalomma marginatum (Acari: Ixodidae). Ticks Tick Borne Dis 2023; 14:102112. [PMID: 36634470 DOI: 10.1016/j.ttbdis.2022.102112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 10/20/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022]
Abstract
Hyalomma marginatum is the main vector of Crimean-Congo haemorrhagic fever virus (CCHFV) and spotted fever rickettsiae in Europe. The distribution of H. marginatum is currently restricted to parts of southern Europe, northern Africa and Asia, and one of the drivers limiting distribution is climate, particularly temperature. As temperatures rise with climate change, parts of northern Europe currently considered too cold for H. marginatum to be able to survive may become suitable, including the United Kingdom (UK), presenting a potential public health concern. Here we use a series of modelling methodologies to understand whether mean air temperatures across the UK during 2000-2019 were sufficient for H. marginatum nymphs to moult into adult stages and be able to overwinter in the UK if they were introduced on migratory birds. We then used UK-specific climate projections (UKCP18) to determine whether predicted temperatures would be sufficient to allow survival in future. We found that spring temperatures in parts of the UK during 2000-2019 were warm enough for predicted moulting to occur, but in all years except 2006, temperatures during September to December were too cold for overwintering to occur. Our analysis of the projections data suggests that whilst temperatures in the UK during September to December will increase in future, they are likely to remain below the threshold required for H. marginatum populations to become established.
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Affiliation(s)
| | - Jolyon M Medlock
- Medical Entomology and Zoonoses Ecology, UK Health Security Agency
| | - Helen Macintyre
- Climate Change and Health, UK Health Security Agency; School of Geography, Earth and Environmental Sciences, University of Birmingham
| | - Revati Phalkey
- Climate Change and Health, UK Health Security Agency; Division of Epidemiology and Public Health, University of Nottingham, UK; Heidelberg Institute for Global Health, University of Germany, Germany
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4
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Li S, Kim C, Zong S, Liu Y, Kang J, Pak C, Cao Z, Wu Y. Dynamic synthesis and transport of fluorescent substances from moulting scorpions. J Photochem Photobiol B 2022; 234:112511. [PMID: 35816856 DOI: 10.1016/j.jphotobiol.2022.112511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 06/27/2022] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
Scorpion fluorescence under ultraviolet light is a well-known phenomenon, and its change is also a known biological feature during the scorpion moulting process. However, the synthesis and transport of fluorescent substances during the moulting stage remain unclear. In this study, in-depth investigations on the global fluorescence changes from the exoskeleton, fluorescence layer, coelomic fluid, and abdomen to the digestive glands indicated that the digestive glands, which occupy most of the space in the abdomen of the scorpion mesosoma segment, were responsible for synthesizing the fluorescent substances. More importantly, these fluorescent substances were produced in advance, before the moulting process, which contributed to the recovery of the fluorescent exoskeleton as early as possible. The synthesized fluorescent substances first entered the coelomic fluid, then successively passed through the inherent epithelial cell layer and two new formed endocuticle and exocuticle layers, and ultimately reached and became enriched in the new formed fluorescent layer, which was protected by the new epicuticle layer. These four new layers were the first to illustrate the structural features of the fluorescent exoskeleton. Due to the very soft body and the inability of the newly moulted scorpion to resist attacks from the predator, this special synthesis and transport strategy of the fluorescent substances could guarantee the rapid formation of the integrated fluorescent exoskeleton during the 24 h after ecdysis, which would be a novel biological feature during the scorpion evolution.
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Affiliation(s)
- Songryong Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Department of Biotechnology, Faculty of Life Science, Kim Hyong Jik University of Education, Pyongyang, Democratic People's Republic of Korea
| | - Cholman Kim
- Department of Biotechnology, Faculty of Life Science, Kim Hyong Jik University of Education, Pyongyang, Democratic People's Republic of Korea
| | - Shaozhi Zong
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yuqing Liu
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jongguk Kang
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Faculty of Life Science, Kim Il Sung University, Pyongyang, Democratic People's Republic of Korea
| | - Cholmin Pak
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Gastrointestinal Hospital, Korean Red Cross General Hospital, Pyongyang, Democratic People's Republic of Korea
| | - Zhijian Cao
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Yingliang Wu
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China.
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Sterkel M, Volonté M, Albornoz MG, Wulff JP, Del Huerto Sánchez M, Terán PM, Ajmat MT, Ons S. The role of neuropeptides in regulating ecdysis and reproduction in the hemimetabolous insect Rhodnius prolixus. J Exp Biol 2022; 225:276563. [PMID: 35929492 DOI: 10.1242/jeb.244696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 07/27/2022] [Indexed: 11/20/2022]
Abstract
In ecdysozoan animals, moulting entails the production of a new exoskeleton and shedding the old one during ecdysis. It is induced by a pulse of ecdysone that regulates the expression of different hormonal receptors and activates a peptide-mediated signalling cascade. In Holometabola, the peptidergic cascade regulating ecdysis has been well described. However, very little functional information regarding the neuroendocrine regulation of ecdysis is available for Hemimetabola, which displays an incomplete metamorphosis. We use Rhodnius prolixus as a convenient experimental model to test two hypotheses: (a) the role of neuropeptides that regulate ecdysis in Holometabola is conserved in hemimetabolous insects; (b) the neuropeptides regulating ecdysis play a role in the regulation of female reproduction during the adult stage. The RNA interference-mediated reduction of ETH expression in fourth-instar nymphs resulted in lethality at the expected time of ecdysis. Unlike in holometabolous insects, the knockdown of ETH and OKA did not affect oviposition in adult females, pointing to a different endocrine regulation of ovary maturation. However, ETH knockdown prevented egg hatching. The blockage of egg hatching appears to be a consequence of embryonic ecdysis failure. Most of the first-instar nymphs hatched from the eggs laid by females injected with dsEH, dsCCAP and dsOKA died at the expected time of ecdysis, indicating the crucial involvement of these genes in post-embryonic development. No phenotypes were observed upon CZ knockdown in nymphs or adult females. The results are relevant for evolutionary entomology and could reveal targets for neuropeptide-based pest control tools.
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Affiliation(s)
- Marcos Sterkel
- Laboratorio de Neurobiología de Insectos (LNI), Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CENEXA, CONICET, La Plata, Buenos Aires, Argentina
| | - Mariano Volonté
- Laboratorio de Neurobiología de Insectos (LNI), Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CENEXA, CONICET, La Plata, Buenos Aires, Argentina
| | - Maximiliano G Albornoz
- Laboratorio de Neurobiología de Insectos (LNI), Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CENEXA, CONICET, La Plata, Buenos Aires, Argentina
| | - Juan Pedro Wulff
- Laboratorio de Neurobiología de Insectos (LNI), Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CENEXA, CONICET, La Plata, Buenos Aires, Argentina
| | - Mariana Del Huerto Sánchez
- Instituto Superior de Investigaciones Biológicas (INSIBIO). Universidad Nacional de Tucumán. Chacabuco 461, T4000, S. M. de Tucumán, Tucumán
| | - Paula María Terán
- Instituto Superior de Investigaciones Biológicas (INSIBIO). Universidad Nacional de Tucumán. Chacabuco 461, T4000, S. M. de Tucumán, Tucumán
| | - María Teresa Ajmat
- Instituto Superior de Investigaciones Biológicas (INSIBIO). Universidad Nacional de Tucumán. Chacabuco 461, T4000, S. M. de Tucumán, Tucumán
| | - Sheila Ons
- Laboratorio de Neurobiología de Insectos (LNI), Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CENEXA, CONICET, La Plata, Buenos Aires, Argentina
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Cresswell T, Prentice E, Howell N, Callaghan P, Metian M, Johansen MP. Bioaccumulation kinetics and internal distribution of the fission products radiocaesium and radiostrontium in an estuarine crab. J Hazard Mater 2021; 408:124453. [PMID: 33168318 DOI: 10.1016/j.jhazmat.2020.124453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/22/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
Crab has been designated by the ICRP as one of twelve reference/model organisms for understanding the impacts of radionuclide releases on the biosphere. However, radionuclide-crab interaction data are sparse compared with other reference organisms (e.g. deer, earthworm). This study used an estuarine crab (Paragrapsus laevis) to investigate the contribution of water, diet and sediment sources to radionuclide (134Cs and 85Sr) bioaccumulation kinetics using live-animal radiotracing. The distribution of each radionuclide within the crab tissues was determined using dissection, whole-body autoradiography and synchrotron X-ray Fluorescence Microscopy (XFM). When moulting occurred during exposure, it caused significant increases in 85Sr bioaccumulation and efflux of 134Cs under constant aqueous exposure. Dietary assimilation efficiencies were determined as 55 ± 1% for 134Cs and 49 ± 3% for 85Sr. 85Sr concentrated in gonads more than other organs, resulting in proportionally greater radiation dose to the reproductive organs and requires further investigation. 134Cs was found in most soft tissues and was closely associated with S and K. Biodynamic modelling suggested that diet accounted for 90-97% of whole-body 137Cs, while water accounted for 59-81% of 90Sr. Our new data on crab, as a representative invertebrate, improves understanding of the impacts of planned or accidental releases of fission radionuclides on marine ecology.
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Affiliation(s)
- Tom Cresswell
- ANSTO, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia.
| | - Emily Prentice
- ANSTO, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia; NSW Office of Environment and Heritage, PO Box 29, Lidcombe, NSW 1825, Australia
| | - Nick Howell
- ANSTO, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Paul Callaghan
- ANSTO, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Marc Metian
- International Atomic Energy Agency Environment Laboratories (IAEA-EL), Radioecology Laboratory, 4a Quai Antoine 1er, Principality of Monaco MC-98000, Monaco
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Bury S. Sex-specific growth is mirrored in feeding rate but not moulting frequency in a sexually dimorphic snake. Naturwissenschaften 2021; 108:6. [PMID: 33415456 DOI: 10.1007/s00114-020-01712-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 11/06/2020] [Accepted: 11/16/2020] [Indexed: 11/30/2022]
Abstract
Sexual size dimorphism (SSD), commonly observed in snakes, may arise from a different growth rate between the sexes. This indicates a sex-specific resource intake that is in fact observable in free-living snakes. It is not so well known whether the sexes can express differential feeding rates under conditions unconstrained by spatial accessibility, competition, etc. Here, I studied sex-specific variation in growth, its correlate-moulting frequency, and feeding rate in a captive group of sexually dimorphic banded water snakes (Nerodia fasciata) with access to food unconstrained by predation, competition or space. I showed that the sexes did indeed differ in relative mass growth in that females grew faster than males (p = 0.02), but such differences were not apparent in the moulting rate (p = 0.19). Such differential growth was mirrored in the sex-specific feeding rate, with females ingesting a larger number of meals than males (p = 0.004). Such variation in feeding rate may be governed by an individual's energy expenditure and can be interpreted as a behavioural tendency that contributes to SSD development, independently of other behavioural characteristics. Sex-specific resource demands may drive the differential effects of increasing resource scarcity on both sexes.
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Affiliation(s)
- Stanisław Bury
- Department of Comparative Anatomy, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland. .,Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland. .,NATRIX Herpetological Association, Legnicka 65, 54-206, Wrocław, Poland.
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8
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Zhang QQ, Qiao M. Transcriptional response of springtail (Folsomia candida) exposed to decabromodiphenyl ether-contaminated soil. Sci Total Environ 2020; 719:134859. [PMID: 31837853 DOI: 10.1016/j.scitotenv.2019.134859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 09/29/2019] [Accepted: 10/05/2019] [Indexed: 05/22/2023]
Abstract
Decabromodiphenyl ether (BDE209) is a widely used brominated flame retardant that has become a common soil contaminant of concern due to its persistence and toxicity. However, little is known about molecular-level effects of BDE209 on soil invertebrates. Here, we detected changes in gene transcription of the soil springtail, Folsomia candida, exposed to BDE209 (0.81 mg/kg) in soil for 2, 7 and 14 days. We identified 16 and 771 significantly differentially expressed genes after 2 and 7 days of exposure respectively, and no significantly regulated genes were shared among the two time points. No genes were affected after 14 days of exposure. According to the annotation of the significantly differently expressed genes at 2 and 7 day exposure, we found that BDE209 affected the transcription of genes involved in moulting, neural signal transmission and detoxification. Our results suggested that BDE209 could disrupt moulting of F. candida via the ecdysteroid pathway, and cause neurotoxicity through disrupting some neurotransmitter signalling pathways. This study provided insights into the toxic mechanism of BDE209 on F. candida.
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Affiliation(s)
- Qian-Qian Zhang
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Qiao
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Abstract
This review covers the systematics and nomenclature of the Ascaridoid genus toxocara, and more specifically the species Toxocara canis and Toxocara cati. Also discussed is the discovery of the persistence of these larvae in the tissues of paratenic hosts, and the role that other species of this genus might or could play in other such hosts; including those where the life cycle has been described, i.e., Toxocara vitulorum, Toxocara pteropodis, Toxocara mackerrasae, and Toxocara tanuki. Also examined is the work that led to the realization that the larval stage leaving the egg actually being a third rather than a second stage larva. Also discussed on the work showing that the larvae can persist in paratenic host with remarkable longevity without undergoing any morphological change for years and that these larvae can be transmitted from one paratenic host to another by ingestion. People are usually infected by the ingestion of eggs containing third-stage larvae, but infections also occur on occasions from the ingestion of uncooked paratenic hosts.
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Affiliation(s)
- Dwight D Bowman
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States.
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10
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Fombad FF, Njouendou AJ, Ndongmo PC, Ritter M, Chunda VC, Metuge HM, Gandjui NVT, Enyong P, Njiokou F, Hoerauf A, Mackenzie CD, Wanji S. Effect of flubendazole on developing stages of Loa loa in vitro and in vivo: a new approach for screening filaricidal agents. Parasit Vectors 2019; 12:14. [PMID: 30621774 PMCID: PMC6323797 DOI: 10.1186/s13071-018-3282-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 12/27/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Loiasis, an often-neglected tropical disease, is a threat to the success of lymphatic filariasis and onchocerciasis elimination programmes in rainforest areas of the central and western Africa. Its control and even its elimination might be possible through the use of a safe macrofilaricide, a prophylactic drug, or perhaps a vaccine. This present study evaluated the effect of flubendazole (FLBZ) on the development of Loa loa L3 in vitro and in vivo. METHODS Infective stages of L. loa were isolated and co-cultured in Dulbecco's Modified Eagle's Medium in the presence of monkey kidney epithelial cells (LLC-MK2) feeder cells. FLBZ and its principal metabolites, reduced flubendazole (RFLBZ) and hydrolyzed flubendazole (HFLBZ), were screened in vitro at concentrations 0.05, 0.1, 0.5, 1 and 10 μg/ml. The viability of the parasites was assessed microscopically daily for 15 days. For in vivo study, a total of 48 CcR3 KO mice were infected subcutaneously with 200 L. loa L3 and treated with 10 mg/kg FLBZ once daily for 5 consecutive days. Twenty-four animals were used as control and received L3 and vehicle. They were dissected at 5, 10, 15 and 20 days post-treatment for worm recovery. RESULTS The motility of L3 larvae in vitro was reduced from the second day of incubation with drugs at in vivo plasma concentration levels, with a strong correlation found between reduced motility and increased drug concentration (Spearman's rho = -0.9, P < 0.0001). Except for HFLBZ (0.05 μg/ml and 0.01 μg/ml), all concentrations of FLBZ, HFLBZ and RFLBZ interrupted the moulting of L. loa infective larvae to L4. In vivo, regardless of the experimental group, there was a decrease in parasite recovery with time. However, at each time point this reduction was more pronounced in the group of animals treated with FLBZ compared to equivalent control. Parasites were recovered from the flubendazole-treated groups only on day 5 post-inoculation at an average rate of 2.1%, a value significantly lower (Mann-Whitney U-test, U = 28, P = 0.0156) than the average of 31.1% recovered from the control group. CONCLUSIONS This study reveals the ability of flubendazole to inhibit the development of L. loa L3 both in vitro and in vivo, and in addition validates the importance of in vitro and animal models of L. loa as tools for the development of drugs against loiasis.
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Affiliation(s)
- Fanny Fri Fombad
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon.,Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Abdel Jelil Njouendou
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon.,Department of Biomedical Science, Faculty of Health Science, University of Buea, Buea, Cameroon
| | - Patrick Chounna Ndongmo
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Manuel Ritter
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Valerine C Chunda
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Haelly M Metuge
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Narcisse Victor T Gandjui
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Peter Enyong
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde, Cameroon
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany.,German Centre for Infection Research (DZIF), Bonn-Cologne partner site, Bonn, Germany
| | - Charles D Mackenzie
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, 48824, USA.,Filariasis Programmes Support Unit, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
| | - Samuel Wanji
- Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon.
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Jiao Y, Preston S, Garcia-Bustos JF, Baell JB, Ventura S, Le T, McNamara N, Nguyen N, Botteon A, Skinner C, Danne J, Ellis S, Koehler AV, Wang T, Chang BCH, Hofmann A, Jabbar A, Gasser RB. Tetrahydroquinoxalines induce a lethal evisceration phenotype in Haemonchus contortus in vitro. Int J Parasitol Drugs Drug Resist 2018; 9:59-71. [PMID: 30690282 PMCID: PMC6357688 DOI: 10.1016/j.ijpddr.2018.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/11/2018] [Accepted: 12/29/2018] [Indexed: 12/12/2022]
Abstract
In the present study, the anthelmintic activity of a human tyrosine kinase inhibitor, AG-1295, and 14 related tetrahydroquinoxaline analogues against Haemonchus contortus was explored. These compounds were screened against parasitic larvae - exsheathed third-stage (xL3) and fourth-stage (L4) - using a whole-organism screening assay. All compounds were shown to have inhibitory effects on larval motility, development and growth, and induced evisceration through the excretory pore in xL3s. The estimated IC50 values ranged from 3.5 to 52.0 μM for inhibition of larval motility or development. Cytotoxicity IC50 against human MCF10A cells was generally higher than 50 μM. Microscopic studies revealed that this eviscerated (Evi) phenotype occurs rapidly (<20 min) and relates to a protrusion of internal tissues and organs (evisceration) through the excretory pore in xL3s; severe pathological damage in L4s as well as a suppression of larval growth in both stages were also observed. Using a relatively low concentration (12.5 μM) of compound m10, it was established that the inhibitor has to be present for a relatively short time (between 30 h and 42 h) during in vitro development from xL3 to L4, to induce the Evi phenotype. Increasing external osmotic pressure prevented evisceration and moulting, and xL3s remained unaffected by the test compound. These results point to a mode of action involving a dysregulation of morphogenetic processes during a critical time-frame, in agreement with the expected behaviour of a tyrosine kinase inhibitor, and suggest potential for development of this compound class as nematocidal drugs. Tetrahydroquinoxalines kill Haemonchus contortus larvae in vitro. Compounds induce a lethal evisceration phenotype (Evi). The Evi phenotype is associated with the timing of ecdysis. These compounds might be developable as nematocidal drugs.
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Affiliation(s)
- Yaqing Jiao
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Sarah Preston
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia; Faculty of Science and Technology, Federation University, Ballarat, Victoria, Australia
| | - Jose F Garcia-Bustos
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Jonathan B Baell
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
| | - Sabatino Ventura
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Thuy Le
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Nicole McNamara
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Nghi Nguyen
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Antony Botteon
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Cameron Skinner
- Centre for Advanced Histology and Microscopy, Peter MacCallum Cancer Centre, Parkville, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
| | - Jill Danne
- Centre for Advanced Histology and Microscopy, Peter MacCallum Cancer Centre, Parkville, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
| | - Sarah Ellis
- Centre for Advanced Histology and Microscopy, Peter MacCallum Cancer Centre, Parkville, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
| | - Anson V Koehler
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Tao Wang
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Bill C H Chang
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia; Yourgene Bioscience, Taipei, Taiwan
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia; Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
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12
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Becker C, Dick JTA, Cunningham EM, Schmitt C, Sigwart JD. The crustacean cuticle does not record chronological age: New evidence from the gastric mill ossicles. Arthropod Struct Dev 2018; 47:498-512. [PMID: 30086392 DOI: 10.1016/j.asd.2018.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 06/08/2023]
Abstract
A proposed method to determine chronological age of crustaceans uses putative annual bands in the gastric mill ossicles of the foregut. The interpretation of cuticle bands as growth rings is based on the idea that ossicles are retained through the moult and could accumulate a continuous record of age. However, recent studies presented conflicting findings on the dynamics of gastric mill ossicles during ecdysis. We herein study cuticle bands in ossicles in four species of commercially important decapod crustaceans (Homarus gammarus, Nephrops norvegicus, Cancer pagurus and Necora puber) in different phases of the moult cycle using dissections, light microscopy, micro-computed tomography and cryo-scanning electron microscopy. Our results demonstrate that the gastric mill is moulted and ossicles are not retained but replaced during ecdysis. It is therefore not plausible to conclude that ossicles register a lifetime growth record as annual bands and thereby provide age information. Other mechanisms for the formation of cuticle bands and their correlation to size-based age estimates need to be considered and the effect of moulting on other cuticle structures where 'annual growth bands' have been reported should be investigated urgently. Based on our results, there is no evidence for a causative link between cuticle bands and chronological age, meaning it is unreliable for determining crustacean age.
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Affiliation(s)
- Carola Becker
- Queen's University Marine Laboratory, 12-13 The Strand, Portaferry, BT22 1PF, Northern Ireland, UK; Humboldt-Universität zu Berlin, Department of Biology, Comparative Zoology, Philippstr. 13, Haus 2, 10115 Berlin, Germany.
| | - Jaimie T A Dick
- Queen's University Marine Laboratory, 12-13 The Strand, Portaferry, BT22 1PF, Northern Ireland, UK; Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, MBC, 97 Lisburn Road, Belfast, BT9 7BL, Northern Ireland, UK.
| | - Eoghan Mánus Cunningham
- Queen's University Marine Laboratory, 12-13 The Strand, Portaferry, BT22 1PF, Northern Ireland, UK.
| | - Clemens Schmitt
- Max Planck Institute of Colloids and Interfaces, Potsdam-Golm Science Park, Am Mühlenberg 1 OT Golm, 14476 Potsdam, Germany.
| | - Julia D Sigwart
- Queen's University Marine Laboratory, 12-13 The Strand, Portaferry, BT22 1PF, Northern Ireland, UK.
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13
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Poley JD, Braden LM, Messmer AM, Igboeli OO, Whyte SK, Macdonald A, Rodriguez J, Gameiro M, Rufener L, Bouvier J, Wadowska DW, Koop BF, Hosking BC, Fast MD. High level efficacy of lufenuron against sea lice (Lepeophtheirus salmonis) linked to rapid impact on moulting processes. Int J Parasitol Drugs Drug Resist 2018; 8:174-188. [PMID: 29627513 PMCID: PMC6039351 DOI: 10.1016/j.ijpddr.2018.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 11/29/2022]
Abstract
Drug resistance in the salmon louse Lepeophtheirus salmonis is a global issue for Atlantic salmon aquaculture. Multiple resistance has been described across most available compound classes with the exception of the benzoylureas. To target this gap in effective management of L. salmonis and other species of sea lice (e.g. Caligus spp.), Elanco Animal Health is developing an in-feed treatment containing lufenuron (a benzoylurea) to be administered prior to seawater transfer of salmon smolts and to provide long-term protection of salmon against sea lice infestations. Benzoylureas disrupt chitin synthesis, formation, and deposition during all moulting events. However, the mechanism(s) of action are not yet fully understood and most research completed to date has focused on insects. We exposed the first parasitic stage of L. salmonis to 700 ppb lufenuron for three hours and observed over 90% reduction in survival to the chalimus II life stage on the host, as compared to vehicle controls. This agrees with a follow up in vivo administration study on the host, which showed >95% reduction by the chalimus I stage. Transcriptomic responses of salmon lice exposed to lufenuron included genes related to moulting, epithelial differentiation, solute transport, and general developmental processes. Global metabolite profiles also suggest that membrane stability and fluidity is impacted in treated lice. These molecular signals are likely the underpinnings of an abnormal moulting process and cuticle formation observed ultrastructurally using transmission electron microscopy. Treated nauplii-staged lice exhibited multiple abnormalities in the integument, suggesting that the coordinated assembly of the epi- and procuticle is impaired. In all cases, treatment with lufenuron had rapid impacts on L. salmonis development. We describe multiple experiments to characterize the efficacy of lufenuron on eggs, larvae, and parasitic stages of L. salmonis, and provide the most comprehensive assessment of the physiological responses of a marine arthropod to a benzoylurea chemical.
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Affiliation(s)
- Jordan D Poley
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Laura M Braden
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Amber M Messmer
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria BC, V8W 3N5, Canada.
| | - Okechukwu O Igboeli
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Shona K Whyte
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Alicia Macdonald
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Jose Rodriguez
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Marta Gameiro
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Lucien Rufener
- Elanco Centre de Recherche Santé Animale SA, CH-1566 St.-Aubin, Switzerland; INVENesis LLC, Chemin de Belleroche 14, 2000 Neuchâtel, Switzerland.
| | - Jacques Bouvier
- Elanco Centre de Recherche Santé Animale SA, CH-1566 St.-Aubin, Switzerland; INVENesis LLC, Chemin de Belleroche 14, 2000 Neuchâtel, Switzerland.
| | - Dorota W Wadowska
- Electron Microscopy Laboratory, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PEI, C1A 4P3, Canada.
| | - Ben F Koop
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria BC, V8W 3N5, Canada.
| | - Barry C Hosking
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Mark D Fast
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
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14
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Wu NC, Cramp RL, Franklin CE. Living with a leaky skin: upregulation of ion transport proteins during sloughing. ACTA ACUST UNITED AC 2018; 220:2026-2035. [PMID: 28566357 DOI: 10.1242/jeb.151738] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 03/20/2017] [Indexed: 11/20/2022]
Abstract
Amphibian skin is a multifunctional organ providing protection from the external environment and facilitating the physiological exchange of gases, water and salts with the environment. In order to maintain these functions, the outer layer of skin is regularly replaced in a process called sloughing. During sloughing, the outermost layer of the skin is removed in its entirety, which has the potential to interfere with skin permeability and ion transport, disrupting homeostasis. In this study, we measured, in vivo, the effects of sloughing on the cutaneous efflux of ions in toads Rhinella marina kept in freshwater conditions. We also measured transepithelial potential, cutaneous resistance, active ion transport and the distribution, abundance and gene expression of the key ion transport proteins sodium-potassium ATPase (NKA) and epithelial sodium channel (ENaC) during sloughing. We hypothesised that the increase in transepithelial efflux of ions during sloughing is a consequence of increased permeability and/or a reduction in the abundance or expression of cutaneous ion transport proteins, resulting in disruption of internal ion homeostasis. There was a significant increase in sodium and chloride efflux during sloughing in R. marina However, although in vitro skin resistance decreased after sloughing, active sodium transport increased commensurate with an increase in NKA and ENaC protein abundance in the skin. These changes in skin function associated with sloughing did not affect the maintenance of internal electrolyte homeostasis. These results suggest that during sloughing, amphibians actively maintain internal homeostasis by increasing cutaneous rates of ion uptake.
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Affiliation(s)
- Nicholas C Wu
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
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15
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Zofou D, Fombad FF, Gandjui NVT, Njouendou AJ, Kengne-Ouafo AJ, Chounna Ndongmo PW, Datchoua-Poutcheu FR, Enyong PA, Bita DT, Taylor MJ, Turner JD, Wanji S. Evaluation of in vitro culture systems for the maintenance of microfilariae and infective larvae of Loa loa. Parasit Vectors 2018; 11:275. [PMID: 29716646 PMCID: PMC5930665 DOI: 10.1186/s13071-018-2852-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/16/2018] [Indexed: 01/28/2023] Open
Abstract
Background Suitable and scalable in vitro culture conditions for parasite maintenance are needed to foster drug research for loiasis, one of the neglected tropical diseases which has attracted only limited attention over recent years, despite having important public health impacts. The present work aims to develop adequate in vitro culture systems for drug screening against both microfilariae (mf) and infective third-stage larvae (L3) of Loa loa. Methods In vitro culture conditions were evaluated by varying three basic culture media: Roswell Park Memorial Institute (RPMI-1640), Dulbecco’s modified Eagle’s medium (DMEM) and Iscove’s modified Dulbecco’s medium (IMDM); four sera/proteins: newborn calf serum (NCS), foetal bovine serum (FBS), bovine serum albumin (BSA) and the lipid-enriched BSA (AlbuMax® II, ALB); and co-culture with the Monkey Kidney Epithelial Cell line (LLC-MK2) as a feeder layer. The various culture systems were tested on both mf and L3, using survival (% motile), motility (T90 = mean duration (days) at which at least 90% of parasites were fully active) and moulting rates of L3 as the major criteria. The general linear model regression analysis was performed to assess the contribution of each variable on the viability of Loa loa L3 and microfilarie. All statistical tests were performed at 95% confidence interval. Results Of the three different media tested, DMEM and IMDM were the most suitable sustaining the maintenance of both L. loa L3 and mf. IMDM alone could sustain L3 for more than 5 days (T90 = 6.5 ± 1.1 day). Serum supplements and LLC-MK2 co-cultures significantly improved the survival of parasites in DMEM and IMDM. In co-cultures with LLC-MK2 cells, L. loa mf were maintained in each of the three basic media (T90 of 16.4–19.5 days) without any serum supplement. The most effective culture systems promoting significant moulting rate of L3 into L4 (at least 25%) with substantial maintenance time were: DMEM + BSA, DMEM + NCS, DMEM-AlbuMax®II, DMEM + FBS all in co-culture with LLC-MK2, and IMDM + BSA (1.5%), DMEM + FBS (10%) and DMEM + NCS (5%) without feeder cells. DMEM + 1% BSA in co-culture scored the highest moulting rate of 57 of 81 (70.37%). The factors that promoted L. loa mf viability included feeder cells (β = 0.490), both IMDM (β = 0.256) and DMEM (β = 0.198) media and the protein supplements NCS (β = 0.052) and FBS (β = 0.022); while for L. loa L3, in addition to feeder cells (β = 0.259) and both IMDM (β = 0.401) and DMEM (β = 0.385) media, the protein supplements BSA (β = 0.029) were found important in maintaining the worm motility. Conclusions The findings from this work display a range of culture requirements for the maintenance of Loa loa stages, which are suitable for developing an effective platform for drug screening. Electronic supplementary material The online version of this article (10.1186/s13071-018-2852-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Denis Zofou
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Fanny Fri Fombad
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Narcisse V T Gandjui
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Abdel Jelil Njouendou
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Arnaud Jonas Kengne-Ouafo
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Patrick W Chounna Ndongmo
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | | | - Peter A Enyong
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon
| | - Dizzle Tayong Bita
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Mark J Taylor
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Joseph D Turner
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Samuel Wanji
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon. .,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon.
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16
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Podlaszczuk P, Włodarczyk R, Janiszewski T, Kaczmarek K, Minias P. When moult overlaps migration: moult-related changes in plasma biochemistry of migrating common snipe. PeerJ 2017; 5:e3057. [PMID: 28286713 PMCID: PMC5344014 DOI: 10.7717/peerj.3057] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 02/02/2017] [Indexed: 11/20/2022] Open
Abstract
Moult of feathers entails considerable physiological and energetic costs to an avian organism. Even under favourable feeding conditions, endogenous body stores and energy reserves of moulting birds are usually severely depleted. Thus, most species of birds separate moult from other energy-demanding activities, such as migration or reproduction. Common snipe Gallinago gallinago is an exception, as during the first autumn migration many young snipe initiate the post-juvenile moult, which includes replacement of body feathers, lesser and median wing coverts, tertials, and rectrices. Here, we evaluated moult-related changes in blood plasma biochemistry of the common snipe during a period of serious trade-off in energy allocation between moult and migration. For this purpose, concentrations of basic metabolites in plasma were evaluated in more than 500 young snipe migrating through Central Europe. We found significant changes in the plasma concentrations of total protein, triglyceride and glucose over the course of moult, while the concentrations of uric acid and albumin did not change. Total protein concentration increased significantly in the initial stage of moult, probably as a result of increased production of keratin, but it decreased to the pre-moult level at the advanced stage of moult. Plasma triglyceride concentration decreased during the period of tertial and rectrice moult, which reflected depletion of endogenous fat reserves. By contrast, glucose concentration increased steadily during the course of moult, which could be caused by increased catabolism of triglycerides (via gluconeogenesis) or, alternatively, due to increased glucocorticoids as a stress response. Our results suggest that physiological changes associated with moult may be considered important determinants of the low pace of migration typical of the common snipe.
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Affiliation(s)
- Patrycja Podlaszczuk
- Department of Biodiversity Studies and Bioeducation, University of Łódź , Łódź , Poland
| | - Radosław Włodarczyk
- Department of Biodiversity Studies and Bioeducation, University of Łódź , Łódź , Poland
| | - Tomasz Janiszewski
- Department of Biodiversity Studies and Bioeducation, University of Łódź , Łódź , Poland
| | | | - Piotr Minias
- Department of Biodiversity Studies and Bioeducation, University of Łódź , Łódź , Poland
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17
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Lenaerts C, Van Wielendaele P, Peeters P, Vanden Broeck J, Marchal E. Ecdysteroid signalling components in metamorphosis and development of the desert locust, Schistocerca gregaria. Insect Biochem Mol Biol 2016; 75:10-23. [PMID: 27180725 DOI: 10.1016/j.ibmb.2016.05.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 05/04/2016] [Accepted: 05/05/2016] [Indexed: 06/05/2023]
Abstract
The arthropod-specific hormone family of ecdysteroids plays an important role in regulating diverse physiological processes, such as moulting and metamorphosis, reproduction, diapause and innate immunity. Ecdysteroids mediate their response by binding to a heterodimeric complex of two nuclear receptors, the ecdysone receptor (EcR) and the retinoid-X-receptor/ultraspiracle (RXR/USP). In this study we investigated the role of EcR and RXR in metamorphosis and development of the desert locust, Schistocerca gregaria. The desert locust is a voracious, phytophagous, swarming pest that can ruin crops and harvests in some of the world's poorest countries. A profound knowledge of the ecdysteroid signalling pathway can be used in the development of more target-specific insecticides to combat this harmful plague insect. Here we report an in-depth profiling study of the transcript levels of EcR and RXR, as well as its downstream response genes, in different tissues isolated throughout the last larval stage of a hemimetabolous insect, showing a clear correlation with circulating ecdysteroid titres. Using RNA interference (RNAi), the role of SgEcR/SgRXR in moulting and development was investigated. We have proven the importance of the receptor components for successful moulting of locust nymphs into the adult stage. Some SgEcR/SgRXR knockdown females were arrested in the last larval stage, and 65 % of them initiated vitellogenesis and oocyte maturation, which normally only occurs in adults. Furthermore, our results clearly indicate that at the peak of ecdysteroid synthesis, on day six of the last larval stage, knockdown of SgEcR/SgRXR is affecting the transcript levels of the Halloween genes, Spook, Shadow and Shade.
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Affiliation(s)
- Cynthia Lenaerts
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59, P.O. Box 02465, B-3000, Leuven, Belgium
| | - Pieter Van Wielendaele
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59, P.O. Box 02465, B-3000, Leuven, Belgium
| | - Paulien Peeters
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59, P.O. Box 02465, B-3000, Leuven, Belgium
| | - Jozef Vanden Broeck
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59, P.O. Box 02465, B-3000, Leuven, Belgium.
| | - Elisabeth Marchal
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59, P.O. Box 02465, B-3000, Leuven, Belgium
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18
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Burrows M. Development and deposition of resilin in energy stores for locust jumping. ACTA ACUST UNITED AC 2016; 219:2449-57. [PMID: 27259374 DOI: 10.1242/jeb.138941] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 05/31/2016] [Indexed: 12/11/2022]
Abstract
Locusts jump by using a catapult mechanism in which energy produced by slow contractions of the extensor tibiae muscles of the hind legs is stored in distortions of the exoskeleton, most notably (1) the two semi-lunar processes at each knee joint and (2) the tendons of the extensor muscles themselves. The energy is then suddenly released from these stores to power the rapid, propulsive movements of the hind legs. The reliance on the mechanical storage of energy is likely to impact on jumping because growth occurs by a series of five moults, at each of which the exoskeleton is replaced by a new one. All developmental stages (instars) nevertheless jump as a means of forward locomotion, or as an escape movement. Here, I show that in each instar, resilin is added to the semi-lunar processes and to the core of the extensor tendons so that their thickness increases. As the next moult approaches, a new exoskeleton forms within the old one, with resilin already present in the new semi-lunar processes. The old exoskeleton, the tendons and their resilin are discarded at moulting. The resilin of the semi-lunar processes and tendons of the new instar is initially thin, but a similar pattern of deposition results in an increase of their thickness. In adults, resilin continues to be deposited so that at 4 weeks old the thickness in the semi-lunar processes has increased fourfold. These changes in the energy stores accompany changes in jumping ability and performance during each moulting cycle.
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Affiliation(s)
- Malcolm Burrows
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
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Daley AC, Drage HB. The fossil record of ecdysis, and trends in the moulting behaviour of trilobites. Arthropod Struct Dev 2016; 45:71-96. [PMID: 26431634 DOI: 10.1016/j.asd.2015.09.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 09/01/2015] [Accepted: 09/14/2015] [Indexed: 06/05/2023]
Abstract
Ecdysis, the process of moulting an exoskeleton, is one of the key characters uniting arthropods, nematodes and a number of smaller phyla into Ecdysozoa. The arthropod fossil record, particularly trilobites, eurypterids and decapod crustaceans, yields information on moulting, although the current focus is predominantly descriptive and lacks a broader evolutionary perspective. We here review literature on the fossil record of ecdysis, synthesising research on the behaviour, evolutionary trends, and phylogenetic significance of moulting throughout the Phanerozoic. Approaches vary widely between taxonomic groups, but an overall theme uniting these works suggests that identifying moults in the palaeontological record must take into account the morphology, taphonomy and depositional environment of fossils. We also quantitatively analyse trends in trilobite ecdysis based on a newly generated database of published incidences of moulting behaviour. This preliminary work reveals significant taxonomic and temporal signal in the trilobite moulting fossil record, with free cheek moulting being prevalent across all Orders and throughout the Phanerozoic, and peaks of cephalic moulting in Phacopida during the Ordovician and rostral plate moulting in Redlichiida during the Cambrian. This study and a review of the literature suggest that it is feasible to extract large-scale evolutionary information from the fossil record of moulting.
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Affiliation(s)
- Allison C Daley
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, United Kingdom; Oxford University Museum of Natural History, Parks Road, Oxford, OX1 3PZ, United Kingdom.
| | - Harriet B Drage
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, United Kingdom; Oxford University Museum of Natural History, Parks Road, Oxford, OX1 3PZ, United Kingdom
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Oku K. Precopulatory mate guarding influences the development of quiescent deutonymph females in the two-spotted spider mite (Acari: Tetranychidae). Exp Appl Acarol 2016; 68:33-38. [PMID: 26530990 DOI: 10.1007/s10493-015-9983-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/22/2015] [Indexed: 06/05/2023]
Abstract
Individuals of some organisms have a specific stage sensitive to environmental cues that initiate developmental plasticity which subsequently influences their entire development. Females may use male behaviour such as precopulatory mate guarding as an environmental cue to change their developmental rate. In the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae), only the first insemination results in fertilization and males guard quiescent deutonymph females. As quiescent individuals take on a silvery appearance before moulting, the period of the quiescent stage can be divided into two parts: from entering the quiescent stage to becoming silvery (1st period) and from becoming silvery to moulting (2nd period). Females may be sensitive to precopulatory mate guarding immediately before moulting (i.e. 2nd period). Thus, I examined whether precopulatory mate guarding during either period affects the total developmental duration of quiescent deutonymph females. When guarded by a male, the whole developmental duration of the quiescent deutonymph females became significantly shorter (by 3-5%) than that of solitary ones, regardless whether the guarding occurred during the 1st period, the 2nd period or both periods. In conclusion, quiescent deutonymph T. urticae females use precopulatory mate guarding by conspecific males as an environmental cue for their developmental rate, although they are sensitive to the mate guarding not only immediately before moulting.
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Affiliation(s)
- Keiko Oku
- Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
- National Agriculture and Food Research Organization (NARO), Agricultural Research Center, Tsukuba, Ibaraki, 305-8666, Japan.
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Ondrovics M, Gasser RB, Joachim A. Recent Advances in Elucidating Nematode Moulting - Prospects of Using Oesophagostomum dentatum as a Model. Adv Parasitol 2015; 91:233-64. [PMID: 27015950 DOI: 10.1016/bs.apar.2015.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
There are major gaps in our knowledge of many molecular biological processes that take place during the development of parasitic nematodes, in spite of the fact that understanding such processes could lead to new ways of treating and controlling parasitic diseases via the disruption of one or more biological pathways in the parasites. Progress in genomics, transcriptomics, proteomics and bioinformatics now provides unique opportunities to investigate the molecular basis of key developmental processes in parasitic nematodes. The porcine nodule worm, Oesophagostomum dentatum, represents a large order (Strongylida) of socioeconomically important nematodes, and provides a useful platform for exploring molecular developmental processes, particularly given that this nematode can be grown and maintained in culture in vitro for periods longer than most other nematodes of this order. In this article, we focus on the moulting process (ecdysis) in nematodes; review recent advances in our understanding of molecular aspects of moulting in O. dentatum achieved by using integrated proteomic-bioinformatic tools and discuss key implications and future prospects for research in this area, also with respect to developing new anti-nematode interventions and biotechnological outcomes.
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Affiliation(s)
- Martina Ondrovics
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Anja Joachim
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
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Rahajarison P, Arimanana AH, Raliniaina M, Stachurski F. Survival and moulting of Amblyomma variegatum nymphs under cold conditions of the Malagasy highlands. Infect Genet Evol 2014; 28:666-75. [PMID: 24999236 DOI: 10.1016/j.meegid.2014.06.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 06/24/2014] [Accepted: 06/26/2014] [Indexed: 11/22/2022]
Abstract
Although Amblyomma variegatum is now regularly recorded up to 1600 m in altitude in the Malagasy highlands, where it was previously reported not to persist without a constant supply of ticks introduced from lower infested regions, some parts of the highlands remain tick-free. Studies were carried out to verify whether the cold climate prevailing in these areas in June-September could prevent the survival and moulting of nymphs, the tick life stage present in the environment at this period. Cohorts of engorged A. variegatum nymphs were released from June to August in six different sites (three in 2010, altitudes 1200-1415 m; three in 2011, altitudes 1585-1960 m) which were reported to be either tick-infested (two in 2010, one in 2011) or tick-free. The ticks were placed in cages driven into the soil and open at the bottom so that they could hide in the soil or root network. Of the 1975 nymphs released in 2010 and the 1494 released in 2011, 86% and 85% were recovered, respectively. Twenty to 23% of the recovered ticks were dead, and some of them were obviously predated; predation also likely contributed to the disappearance of the non-recovered ticks. When the rainy season started in October, 59% of the newly moulted adults were still alive in the cages. The moulting period lasted up to 20 weeks, depending on the site and release period. As verified in 2011, unfed nymphs could also survive the cold season. Various A. variegatum life stages are thus able to survive the adverse cold and/or dry seasons: unfed nymphs, engorged nymphs in developmental diapause, moulted adults in behavioural diapause as observed previously. Strong variation in mortality and recovery rates was observed between cages, highlighting the importance of the micro-environment and micro-climate for tick survival. The minimum temperature recorded in the field sites varied from 1.1 °C to 6.8 °C, but the tick-free sites were not the coldest ones; they were, however, those for which the temperature remained below 10 °C for the longest time over the study period. Recovery and mortality rates in the tick-free sites were similar to those of the tick-infested sites: the temperatures recorded during the study periods did not prevent ticks from surviving and moulting although it did delay the metamorphosis. Low temperature alone can therefore not explain the persistence of tick-free areas in the highlands. To further monitor survival, cohorts of engorged nymphs were also maintained in an incubator at 3.6 °C, 6.2 °C or 12.8 °C. More than 50% mortality was observed after 6 days at 3.6 °C, and after 15 days at 6.2 °C, whereas 18 days at 12.8 °C only delayed moulting. The collected survival, moulting and climatic data presented in this study should help to develop a predictive model to assess the distribution of A. variegatum according to climate characteristics.
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Page AP, Stepek G, Winter AD, Pertab D. Enzymology of the nematode cuticle: A potential drug target? Int J Parasitol Drugs Drug Resist 2014; 4:133-41. [PMID: 25057463 PMCID: PMC4095051 DOI: 10.1016/j.ijpddr.2014.05.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 05/14/2014] [Accepted: 05/15/2014] [Indexed: 11/16/2022]
Abstract
All nematodes possess an external structure known as the cuticle, which is crucial for their development and survival. This structure is composed primarily of collagen, which is secreted from the underlying hypodermal cells. Extensive studies using the free-living nematode Caenorhabditis elegans demonstrate that formation of the cuticle requires the activity of an extensive range of enzymes. Enzymes are required both pre-secretion, for synthesis of component proteins such as collagen, and post-secretion, for removal of the previous developmental stage cuticle, in a process known as moulting or exsheathment. The excretion/secretion products of numerous parasitic nematodes contain metallo-, serine and cysteine proteases, and these proteases are conserved across the nematode phylum and many are involved in the moulting/exsheathment process. This review highlights the enzymes required for cuticle formation, with a focus on the post-secretion moulting events. Where orthologues of the C. elegans enzymes have been identified in parasitic nematodes these may represent novel candidate targets for future drug/vaccine development.
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Affiliation(s)
- Antony P Page
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
| | - Gillian Stepek
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
| | - Alan D Winter
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
| | - David Pertab
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
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Kamio M, Schmidt M, Germann MW, Kubanek J, Derby CD. The smell of moulting: N-acetylglucosamino-1,5-lactone is a premoult biomarker and candidate component of the courtship pheromone in the urine of the blue crab, Callinectes sapidus. ACTA ACUST UNITED AC 2013; 217:1286-96. [PMID: 24363413 DOI: 10.1242/jeb.099051] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Female blue crabs (Callinectes sapidus) in their pubertal moult stage release unidentified sex pheromone molecules in their urine, causing males to respond with courtship behaviours including a display called courtship stationary paddling and a form of precopulatory guarding called cradle carry. We hypothesized that pheromones are mixtures of molecules and are more concentrated in urine of pubertal premoult females compared with other moulting stages and thus that these molecules are biomarkers (i.e. metabolites that can be used as an indicator of some biological state or condition) of pubertal premoult females. We tested this hypothesis by combining bioassay-guided fractionation and biomarker targeting. To evaluate the molecular mass of the putative pheromone by bioassay-guided fractionation, we separated urine from pubertal premoult females and intermoult males by ultrafiltration into three molecular mass fractions. The <500 Da fraction and the 500-1000 Da fraction but not the >1000 Da fraction of female urine induced male courtship stationary paddling, but none of the fractions of male urine did. Thus, female urine contains molecules of <1000 Da that stimulate courtship behaviours in males. Biomarker targeting using nuclear magnetic resonance (NMR) spectral analysis of the 500-1000 Da fraction of urine from premoult and postmoult males and females revealed a premoult biomarker. Purification, nuclear magnetic resonance, mass spectrometry and high pressure liquid chromatography analysis of this premoult biomarker identified it as N-acetylglucosamino-1,5-lactone (NAGL) and showed that it is more abundant in urine of premoult females and males than in urine of either postmoult or juvenile females and males. NAGL has not been reported before as a natural product or as a molecule of the chitin metabolic pathway. Physiological and behavioural experiments demonstrated that blue crabs can detect NAGL through their olfactory pathway. Thus, we hypothesize that NAGL is a component of the sex pheromone and that it acts in conjunction with other yet unidentified components.
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Affiliation(s)
- Michiya Kamio
- Neuroscience Institute, Department of Biology, Brains & Behavior Program, and Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30302-5030, USA
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Maxime V, Hassani S. Blood oxygen- and carbon dioxide-carrying properties in captive penguins: effects of moulting and inter-specific comparison. Comp Biochem Physiol A Mol Integr Physiol 2013; 168:76-81. [PMID: 24231467 DOI: 10.1016/j.cbpa.2013.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/19/2013] [Accepted: 11/06/2013] [Indexed: 11/25/2022]
Abstract
Venous blood gas-carrying properties were compared in the three captive species of penguins (king, gentoo and rockhopper) at Océanopolis (France). Captivity permitted to control environmental influences. Given their different ecology and diving behaviour in the wild, it was wondered whether milder conditions and dive privation have repercussions on parameters determining oxygen storage and acid-base status of these birds. In addition, this work provided the opportunity to study the effects of moulting in king penguins. This annual event that imposes deep metabolic adjustments is liable to affect blood gas levels. Because of the regular food supply and probably also of the blood sampling conditions, the blood pH of captive penguins was low. This effect was increased in moulting penguins and supposedly due to both the decreased energetic metabolism and the production of uric acid resulting from new feather synthesis. The decrease in the anion gap also revealed the use of plasmatic albumin for this synthesis. The elevated venous PO2 in all birds is not likely due to stress caused by sampling conditions. The other data, in accordance with those in the literature, show neither major influence of captivity nor fundamental interspecific differences, despite potential diving aptitude.
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Affiliation(s)
- Valérie Maxime
- Université de Bretagne Sud (UEB), Centre d'Enseignement et de Recherche Yves Coppens, LIMATB (EG2B), Campus de Tohannic, 56017 Vannes Cedex, France.
| | - Sami Hassani
- Océanopolis, Port de plaisance du Moulin Blanc, BP 411, 29275 Brest Cedex, France
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Zhang S, Jiang S, Xiong Y, Fu H, Sun S, Qiao H, Zhang W, Jiang F, Jin S, Gong Y. Six chitinases from oriental river prawn Macrobrachium nipponense: cDNA characterization, classification and mRNA expression during post-embryonic development and moulting cycle. Comp Biochem Physiol B Biochem Mol Biol 2013; 167:30-40. [PMID: 24096116 DOI: 10.1016/j.cbpb.2013.09.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/26/2013] [Accepted: 09/26/2013] [Indexed: 01/29/2023]
Abstract
Chitinase plays crucial physiological roles in crustaceans, including the digestion of chitin-containing food, moulting and the defense of shrimp against viruses. However, in contrast to insect species, no genome-wide analysis has been carried out in crustacean species and cDNAs encoding chitinase and chitinase-like proteins have been characterized in relatively few species. In this study, we identified six chitinase genes in the oriental river prawn, Macrobrachium nipponense, according to the established expressed sequence tag (EST) information using Rapid Amplification of the cDNA Ends (RACE) technique and homology cloning. We assigned these genes to three different chitinase groupings, which were designated MnCht1A, 1B, 3A, 3B, 3C and 4. The domain organization analysis of the six MnCht proteins revealed that only MnCht3C and MnCht4 possessed full structure, while MnCht1A, 1B, 3A and 3B lacked the serine/threonine (S/T)-rich linker and chitin-binding domains (CBDs). Their expression in different tissues and different developmental stages suggested that all of them have a function in the digestion of chitinous foods, modification of gut peritrophic membrane and degradation of the chitin exoskeleton. Analysis of the stage-specific moulting cycle and different temperature stimulation provided further evidence that MnCht1A, 1B and 3B have pivotal roles in the moulting cycle, while MnCht 4 only assists in the moulting process. This study provides important information for further investigations on the functions of chitinase in M. nipponense and other crustaceans.
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Affiliation(s)
- Shiyong Zhang
- Wuxi Fishery College Nanjing Agricultural University, Wuxi 214081, China
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