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Duong B, Cutmore SC, Cribb TH, Pitt KA, Wee NQX, Bray RA. A new species, new host records and life cycle data for lepocreadiids (Digenea) of pomacentrid fishes from the Great Barrier Reef, Australia. Syst Parasitol 2022; 99:375-397. [PMID: 35394638 PMCID: PMC9023400 DOI: 10.1007/s11230-022-10034-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/09/2022] [Indexed: 11/10/2022]
Abstract
A new species of lepocreadiid, Opechonoides opisthoporusn. sp., is described infecting 12 pomacentrid fish species from the Great Barrier Reef, Australia, with Abudefduf whitleyi Allen & Robertson as the type-host. This taxon differs from the only other known member of the genus, Opechonoides gure Yamaguti, 1940, in the sucker width ratio, cirrus-sac length, position of the testes, position of the pore of Laurer’s canal, and relative post-testicular distance. The new species exhibits stenoxenic host-specificity, infecting pomacentrids from seven genera: Abudefduf Forsskål, Amphiprion Bloch & Schneider, Neoglyphidodon Allen, Neopomacentrus Allen, Plectroglyphidodon Fowler & Ball, Pomacentrus Lacépède and Stegastes Jenyns. Phylogenetic analyses of 28S rDNA sequence data demonstrate that O. opisthoporusn. sp. forms a strongly supported clade with Prodistomum orientale (Layman, 1930) Bray & Gibson, 1990. The life cycle of this new species is partly elucidated on the basis of ITS2 rDNA sequence data; intermediate hosts are shown to be three species of Ctenophora. New host records and molecular data are reported for Lepocreadium oyabitcha Machida, 1984 and Lepotrema amblyglyphidodonis Bray, Cutmore & Cribb, 2018, and new molecular data are provided for Lepotrema acanthochromidis Bray, Cutmore & Cribb, 2018 and Lepotrema adlardi (Bray, Cribb & Barker, 1993) Bray & Cribb, 1996. Novel cox1 mtDNA sequence data showed intraspecific geographical structuring between Heron Island and Lizard Island for L. acanthochromidis but not for L. adlardi or O. opisthoporusn. sp.
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Affiliation(s)
- Berilin Duong
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Scott C Cutmore
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Thomas H Cribb
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Kylie A Pitt
- School of Environment and Science and Australian Rivers Institute, Griffith University, Gold Coast Campus, Gold Coast, QLD, 4222, Australia
| | - Nicholas Q-X Wee
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Rodney A Bray
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, United Kingdom
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Mikulíček P, Mešková M, Cyprich M, Jablonski D, Papežík P, Hamidi D, Pekşen ÇA, Vörös J, Herczeg D, Benovics M. Weak population‐genetic structure of a widely distributed nematode parasite of frogs in the western Palearctic. J ZOOL SYST EVOL RES 2021. [DOI: 10.1111/jzs.12575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Peter Mikulíček
- Department of Zoology Faculty of Natural Sciences Comenius University in Bratislava Bratislava Slovakia
| | - Michaela Mešková
- Department of Zoology Faculty of Natural Sciences Comenius University in Bratislava Bratislava Slovakia
| | - Martin Cyprich
- Department of Zoology Faculty of Natural Sciences Comenius University in Bratislava Bratislava Slovakia
| | - Daniel Jablonski
- Department of Zoology Faculty of Natural Sciences Comenius University in Bratislava Bratislava Slovakia
| | - Petr Papežík
- Department of Zoology Faculty of Natural Sciences Comenius University in Bratislava Bratislava Slovakia
| | - Diyar Hamidi
- Department of Molecular Biology and Genetics Başkent University Ankara Turkey
| | - Çiğdem Akın Pekşen
- Department of Molecular Biology and Genetics Başkent University Ankara Turkey
| | - Judit Vörös
- Department of Zoology Hungarian Natural History Museum Budapest Hungary
| | - David Herczeg
- Lendület Evolutionary Ecology Research Group Plant Protection Institute Centre for Agricultural Research Eötvös Loránd Research Network Budapest Hungary
| | - Michal Benovics
- Department of Zoology Faculty of Natural Sciences Comenius University in Bratislava Bratislava Slovakia
- Department of Botany and Zoology Faculty of Science Masaryk University Brno Czech Republic
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Warburton EM, Blanar CA. Life in the margins: host-parasite relationships in ecological edges. Parasitol Res 2021; 120:3965-3977. [PMID: 34694518 DOI: 10.1007/s00436-021-07355-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 10/18/2021] [Indexed: 11/24/2022]
Abstract
Transitional zones, such as edge habitat, are key landscapes for investigating biodiversity. "Soft edges" are permeable corridors that hosts can cross, while "hard edges" are impermeable borders that hosts cannot pass. Although pathogen transmission in the context of edges is vital to species conservation, drivers of host-parasite relationships in ecological edges remain poorly understood. Thus, we defined a framework for testing hypotheses of host-parasite interactions in hard and soft edges by (1) characterizing hard and soft edges from both the host and parasite perspectives, (2) predicting the types of parasites that would be successful in each type of edge, and (3) applying our framework to species invasion fronts as an example of host-parasite relationships in a soft edge. Generally, we posited that parasites in soft edges are more likely to be negatively affected by habitat fragmentation than their hosts because they occupy higher trophic levels but parasite transmission would benefit from increased host connectivity. Parasites along hard edges, however, are at higher risk of local extinction due to host population perturbations with limited opportunity for parasite recolonization. We then used these characteristics to predict functional traits that would lead to parasite success along soft and hard edges. Finally, we applied our framework to invasive species fronts to highlight predictions regarding host connectivity and parasite traits in soft edges. We anticipate that our work will promote a more complete discussion of habitat connectivity using a common framework and stimulate empirical research into host-parasite relationships within ecological edges and transitional zones.
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Affiliation(s)
- Elizabeth M Warburton
- Center for the Ecology of Infectious Diseases, Odum School of Ecology, University of Georgia, Athens, GA, 30606, USA.
| | - Christopher A Blanar
- Department of Biological Sciences, Halmos College of Arts and Sciences, Nova Southeastern University, Davie, FL, 33314, USA
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Prunier JG, Saint‐Pé K, Blanchet S, Loot G, Rey O. Molecular approaches reveal weak sibship aggregation and a high dispersal propensity in a non-native fish parasite. Ecol Evol 2021; 11:6080-6090. [PMID: 34141204 PMCID: PMC8207417 DOI: 10.1002/ece3.7415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 11/19/2022] Open
Abstract
Inferring parameters related to the aggregation pattern of parasites and to their dispersal propensity are important for predicting their ecological consequences and evolutionary potential. Nonetheless, it is notoriously difficult to infer these parameters from wildlife parasites given the difficulty in tracking these organisms. Molecular-based inferences constitute a promising approach that has yet rarely been applied in the wild. Here, we combined several population genetic analyses including sibship reconstruction to document the genetic structure, patterns of sibship aggregation, and the dispersal dynamics of a non-native parasite of fish, the freshwater copepod ectoparasite Tracheliastes polycolpus. We collected parasites according to a hierarchical sampling design, with the sampling of all parasites from all host individuals captured in eight sites spread along an upstream-downstream river gradient. Individual multilocus genotypes were obtained from 14 microsatellite markers, and used to assign parasites to full-sib families and to investigate the genetic structure of T. polycolpus among both hosts and sampling sites. The distribution of full-sibs obtained among the sampling sites was used to estimate individual dispersal distances within families. Our results showed that T. polycolpus sibs tend to be aggregated within sites but not within host individuals. We detected important upstream-to-downstream dispersal events of T. polycolpus between sites (modal distance: 25.4 km; 95% CI [22.9, 27.7]), becoming scarcer as the geographic distance from their family core location increases. Such a dispersal pattern likely contributes to the strong isolation-by-distance observed at the river scale. We also detected some downstream-to-upstream dispersal events (modal distance: 2.6 km; 95% CI [2.2-23.3]) that likely result from movements of infected hosts. Within each site, the dispersal of free-living infective larvae among hosts likely contributes to increasing genetic diversity on hosts, possibly fostering the evolutionary potential of T. polycolpus.
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Affiliation(s)
| | - Keoni Saint‐Pé
- Station d'Écologie Théorique et ExpérimentaleUPR 2021MoulisFrance
| | - Simon Blanchet
- Station d'Écologie Théorique et ExpérimentaleUPR 2021MoulisFrance
- Laboratoire Evolution et Diversité Biologique (EDB), UMR 5174, Université Toulouse 3 Paul Sabatier, CNRS, IRDToulouseFrance
| | - Géraldine Loot
- Laboratoire Evolution et Diversité Biologique (EDB), UMR 5174, Université Toulouse 3 Paul Sabatier, CNRS, IRDToulouseFrance
| | - Olivier Rey
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via DomitiaPerpignanFrance
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Population genomic analyses of schistosome parasites highlight critical challenges facing endgame elimination efforts. Sci Rep 2021; 11:6884. [PMID: 33767307 PMCID: PMC7994584 DOI: 10.1038/s41598-021-86287-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 03/09/2021] [Indexed: 12/14/2022] Open
Abstract
Schistosomiasis persists in Asian regions despite aggressive elimination measures. To identify factors enabling continued parasite transmission, we performed reduced representation genome sequencing on Schistosoma japonicum miracidia collected across multiple years from transmission hotspots in Sichuan, China. We discovered strong geographic structure, suggesting that local, rather than imported, reservoirs are key sources of persistent infections in the region. At the village level, parasites collected after referral for praziquantel treatment are closely related to local pre-treatment populations. Schistosomes within villages are also highly related, suggesting that only a few parasites from a limited number of hosts drive re-infection. The close familial relationships among miracidia from different human hosts also implicate short transmission routes among humans. At the individual host level, genetic evidence indicates that multiple humans retained infections following referral for treatment. Our findings suggest that end-game schistosomiasis control measures should focus on completely extirpating local parasite reservoirs and confirming successful treatment of infected human hosts.
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Galaktionov KV, Solovyeva AI, Miroliubov A. Elucidation of Himasthla leptosoma (Creplin, 1829) Dietz, 1909 (Digenea, Himasthlidae) life cycle with insights into species composition of the north Atlantic Himasthla associated with periwinkles Littorina spp. Parasitol Res 2021; 120:1649-1668. [PMID: 33712931 DOI: 10.1007/s00436-021-07117-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 03/04/2021] [Indexed: 11/24/2022]
Abstract
Trematodes of the genus Himasthla are usual parasites of coastal birds in nearshore ecosystems of northern European seas and the Atlantic coast of North America. Their first intermediate hosts are marine and brackish-water gastropods, while second intermediate hosts are various invertebrates. We analysed sequences of partial 28S rRNA and nad1 genes and the morphology of intramolluscan stages, particularly cercariae of Himasthla spp. parasitizing intertidal molluscs Littorina spp. in the White Sea, the Barents Sea and coasts of North Norway and Iceland. We showed that only three Himasthla spp. are associated with periwinkles in these regions. Intramolluscan stages of H. elongata were found in Littorina littorea, of H. littorinae, in both L. saxatilis and L. obtusata, and of Cercaria littorinae obtusatae, predominantly, in L. obtusata. Other Himasthla spp. previously reported from Littorina spp. in North Atlantic are either synonymous with one of these species or described erroneously. Based on a comparison of newly generated 28S rDNA sequences with GenBank data, rediae and cercariae of C. littorinae obtusatae were identified as belonging to H. leptosoma. Some previously unknown morphological features of young and mature rediae and cercariae of the three Himasthla spp. are described. We provide a key to the rediae and highlight characters important for identification of cercariae. Genetic diversity within the studied species was only partially determined by their specificity to the molluscan host. The nad1 network constructed for H. leptosoma lacked geographical structure, which is explained by a high gene flow owing to highly vagile definitive hosts, shorebirds.
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Affiliation(s)
- Kirill V Galaktionov
- Laboratory of Parasitic Worms and Protists, Zoological Institute of Russian Academy of Sciences, St. Petersburg, 199034, Russia.
| | - Anna I Solovyeva
- Laboratory of Parasitic Worms and Protists, Zoological Institute of Russian Academy of Sciences, St. Petersburg, 199034, Russia.,Laboratory of Non-Coding DNA, Institute of Cytology of Russian Academy of Sciences, St. Petersburg, 194064, Russia
| | - Alexei Miroliubov
- Laboratory of Parasitic Worms and Protists, Zoological Institute of Russian Academy of Sciences, St. Petersburg, 199034, Russia
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Nikolakis ZL, Hales NR, Perry BW, Schield DR, Timm LE, Liu Y, Zhong B, Kechris KJ, Carlton EJ, Pollock DD, Castoe TA. Patterns of relatedness and genetic diversity inferred from whole genome sequencing of archival blood fluke miracidia (Schistosoma japonicum). PLoS Negl Trop Dis 2021; 15:e0009020. [PMID: 33406094 PMCID: PMC7815185 DOI: 10.1371/journal.pntd.0009020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 01/19/2021] [Accepted: 11/30/2020] [Indexed: 02/05/2023] Open
Abstract
Genomic approaches hold great promise for resolving unanswered questions about transmission patterns and responses to control efforts for schistosomiasis and other neglected tropical diseases. However, the cost of generating genomic data and the challenges associated with obtaining sufficient DNA from individual schistosome larvae (miracidia) from mammalian hosts have limited the application of genomic data for studying schistosomes and other complex macroparasites. Here, we demonstrate the feasibility of utilizing whole genome amplification and sequencing (WGS) to analyze individual archival miracidia. As an example, we sequenced whole genomes of 22 miracidia from 11 human hosts representing two villages in rural Sichuan, China, and used these data to evaluate patterns of relatedness and genetic diversity. We also down-sampled our dataset to test how lower coverage sequencing could increase the cost effectiveness of WGS while maintaining power to accurately infer relatedness. Collectively, our results illustrate that population-level WGS datasets are attainable for individual miracidia and represent a powerful tool for ultimately providing insight into overall genetic diversity, parasite relatedness, and transmission patterns for better design and evaluation of disease control efforts.
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Affiliation(s)
- Zachary L. Nikolakis
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
| | - Nicole R. Hales
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
| | - Blair W. Perry
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
| | - Drew R. Schield
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
| | - Laura E. Timm
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Yang Liu
- Institute of Parasitic Disease, Sichuan Center for Disease Control and Prevention, Chengdu, The People’s Republic of China
| | - Bo Zhong
- Institute of Parasitic Disease, Sichuan Center for Disease Control and Prevention, Chengdu, The People’s Republic of China
| | - Katerina J. Kechris
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado, Anschutz, Aurora, Colorado, United States of America
| | - Elizabeth J. Carlton
- Department of Environmental and Occupational Health, Colorado School of Public Health, University of Colorado, Anschutz, Aurora, Colorado, United States of America
| | - David D. Pollock
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Todd A. Castoe
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
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Zemmer SA, Detwiler JT, Sokol ER, Da Silva Neto JG, Wyderko J, Potts K, Gajewski ZJ, Sarment LV, Benfield EF, Belden LK. Spatial scale and structure of complex life cycle trematode parasite communities in streams. PLoS One 2020; 15:e0241973. [PMID: 33232346 PMCID: PMC7685432 DOI: 10.1371/journal.pone.0241973] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 10/23/2020] [Indexed: 11/19/2022] Open
Abstract
By considering the role of site-level factors and dispersal, metacommunity concepts have advanced our understanding of the processes that structure ecological communities. In dendritic systems, like streams and rivers, these processes may be impacted by network connectivity and unidirectional current. Streams and rivers are central to the dispersal of many pathogens, including parasites with complex, multi-host life cycles. Patterns in parasite distribution and diversity are often driven by host dispersal. We conducted two studies at different spatial scales (within and across stream networks) to investigate the importance of local and regional processes that structure trematode (parasitic flatworms) communities in streams. First, we examined trematode communities in first-intermediate host snails (Elimia proxima) in a survey of Appalachian headwater streams within the Upper New River Basin to assess regional turnover in community structure. We analyzed trematode communities based on both morphotype (visual identification) and haplotype (molecular identification), as cryptic diversity in larval trematodes could mask important community-level variation. Second, we examined communities at multiple sites (headwaters and main stem) within a stream network to assess potential roles of network position and downstream drift. Across stream networks, we found a broad scale spatial pattern in morphotype- and haplotype-defined communities due to regional turnover in the dominant parasite type. This pattern was correlated with elevation, but not with any other environmental factors. Additionally, we found evidence of multiple species within morphotypes, and greater genetic diversity in parasites with hosts limited to in-stream dispersal. Within network parasite prevalence, for at least some parasite taxa, was related to several site-level factors (elevation, snail density and stream depth), and total prevalence decreased from headwaters to main stem. Variation in the distribution and diversity of parasites at the regional scale may reflect differences in the abilities of hosts to disperse across the landscape. Within a stream network, species-environment relationships may counter the effects of downstream dispersal on community structure.
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Affiliation(s)
- Sally A. Zemmer
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
- * E-mail:
| | | | - Eric R. Sokol
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
| | - Jeronimo G. Da Silva Neto
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
| | - Jennie Wyderko
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
| | - Kevin Potts
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
| | - Zachary J. Gajewski
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
| | - Lea V. Sarment
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
| | - E. F. Benfield
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
| | - Lisa K. Belden
- Biological Sciences, Virginia Polytechnic and State Institute, Blacksburg, Virginia, United States of America
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Short communication: New data support phylogeographic patterns in a marine parasite Tristriata anatis (Digenea: Notocotylidae). J Helminthol 2019; 94:e79. [PMID: 31462333 DOI: 10.1017/s0022149x19000786] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Intraspecific diversity in parasites with heteroxenous life cycles is guided by reproduction mode, host vagility and dispersal, transmission features and many other factors. Studies of these factors in Digenea have highlighted several important patterns. However, little is known about intraspecific variation for digeneans in the marine Arctic ecosystems. Here we analyse an extended dataset of partial cox1 and nadh1 sequences for Tristriata anatis (Notocotylidae) and confirm the preliminary findings on its distribution across Eurasia. Haplotypes are not shared between Europe and the North Pacific, suggesting a lack of current connection between these populations. Periwinkle distribution and anatid migration routes are consistent with such a structure of haplotype network. The North Pacific population appears ancestral, with later expansion of T. anatis to the North Atlantic. Here the parasite circulates widely, but the direction of haplotype transfer from the north-east to the south-west is more likely than the opposite. In the eastern Barents Sea, the local transmission hotspot is favoured.
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Blanton RE. Population Structure and Dynamics of Helminthic Infection: Schistosomiasis. Microbiol Spectr 2019; 7:10.1128/microbiolspec.ame-0009-2019. [PMID: 31325285 PMCID: PMC6650164 DOI: 10.1128/microbiolspec.ame-0009-2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Indexed: 11/20/2022] Open
Abstract
While disease and outbreaks are mainly clonal for bacteria and other asexually reproducing organisms, sexual reproduction in schistosomes and other helminths usually results in unique individuals. For sexually reproducing organisms, the traits conserved in clones will instead be conserved in the group of organisms that tends to breed together, the population. While the same tools are applied to characterize DNA, how results are interpreted can be quite different at times (see another article in this collection, http://www.asmscience.org/content/journal/microbiolspec/10.1128/microbiolspec.AME-0002-2018). It is difficult to know what the real effect any control program has on the parasite population without assessing the health of this population, how they respond to the control measure, and how they recover, if they do. This review, part of the Microbiology Spectrum Curated Collection: Advances in Molecular Epidemiology of Infectious Diseases, concentrates on one approach using pooled samples to study schistosome populations and shows how this and other approaches have contributed to our understanding of this parasite family's biology and epidemiology. *This article is part of a curated collection.
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Affiliation(s)
- Ronald E Blanton
- Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44120
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Rapid divergence, molecular evolution, and morphological diversification of coastal host-parasite systems from southern Brazil. Parasitology 2019; 146:1313-1332. [PMID: 31142390 DOI: 10.1017/s0031182019000556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study assessed the role of historical processes on the geographic isolation, molecular evolution, and morphological diversification of host-parasite populations from the southern Brazilian coast. Adult specimens of Scleromystax barbatus and Scleromystax macropterus were collected from the sub-basin of the Nhundiaquara River and the sub-basin of the Paranaguá Bay, state of Paraná, Brazil. Four species of Gyrodactylus were recovered from the body surface of both host species. Morphometric analysis of Gyrodactylus spp. and Scleromystax spp. indicated that subpopulations of parasites and hosts could be distinguished from different sub-basins and locations, but the degree of morphological differentiation seems to be little related to geographic distance between subpopulations. Phylogenetic relationships based on DNA sequences of Gyrodactylus spp. and Scleromystax spp. allowed distinguishing lineages of parasites and hosts from different sub-basins. However, the level of genetic structuring of parasites was higher in comparison to host species. Evidence of positive selection in mtDNA sequences is likely associated with local adaptation of lineages of parasites and hosts. A historical demographic analysis revealed that populations of Gyrodactylus and Scleromystax have expanded in the last 250 000 years. The genetic variation of parasites and hosts is consistent with population-specific selection, population expansions, and recent evolutionary co-divergence.
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Moon KL, Aitkenhead IJ, Fraser CI, Chown SL. Can a Terrestrial Ectoparasite Disperse with Its Marine Host? Physiol Biochem Zool 2019; 92:163-176. [PMID: 30694106 DOI: 10.1086/701726] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
One of the most extreme examples of parasite adaptation comes from terrestrial ectoparasites exploiting marine hosts. Despite the ubiquity of such ectoparasitism and its ecological and evolutionary importance, investigations of the responses of ectoparasites to conditions encountered on their hosts are rare. In the case of penguins and their ticks, current understanding suggests that ticks freely parasitize their hosts on land but are incapable of surviving extended oceanic journeys. We examined this conjecture by assessing the physiological capacity of little penguin ticks to endure at-sea foraging and dispersal events of their hosts. Survival in penguins ticks was not significantly compromised by exposure to depths commonly associated with host dives (40 and 60 m), repeated seawater exposure relevant to the most common (30 s) and longest (120 s) recorded host dives, or extended (48 h) exposure to seawater. Mean (±SD) closed-phase durations in adult and nymphal ticks exhibiting discontinuous gas exchange ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>339</mml:mn><mml:mo>±</mml:mo><mml:mn>237</mml:mn></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>240</mml:mn><mml:mo>±</mml:mo><mml:mn>295</mml:mn></mml:mrow></mml:math> s, respectively) exceeded that of the maximum recorded host dive duration (120 s). Normoxic-anoxic-normoxic respirometry also confirmed spiracle closure. Mean metabolic rates ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>0.354</mml:mn><mml:mo>±</mml:mo><mml:mn>0.220</mml:mn></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>4.853</mml:mn><mml:mo>±</mml:mo><mml:mn>4.930</mml:mn></mml:mrow></mml:math> μL/h at 25°C for unfed and fed adult females, respectively) were significantly influenced by temperature; optimal and LT50 temperatures for adult ticks and fed nymphal ticks were typically higher than swimming penguin body temperatures. These findings suggest that marine host dispersal is unlikely to present an insurmountable barrier to long-distance tick dispersal. Such dispersal has important implications for evolutionary theory, conservation, and epidemiology.
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Phylogeography of the black rat Rattus rattus in India and the implications for its dispersal history in Eurasia. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1830-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Matthee CA, Engelbrecht A, Matthee S. Comparative phylogeography of parasitic Laelaps mites contribute new insights into the specialist-generalist variation hypothesis (SGVH). BMC Evol Biol 2018; 18:131. [PMID: 30176805 PMCID: PMC6122474 DOI: 10.1186/s12862-018-1245-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 08/16/2018] [Indexed: 11/10/2022] Open
Abstract
Background The specialist-generalist variation hypothesis (SGVH) in parasites suggests that, due to patchiness in habitat (host availability), specialist species will show more subdivided population structure when compared to generalist species. In addition, since specialist species are more prone to local stochastic extinction events with their hosts, they will show lower levels of intraspecific genetic diversity when compared to more generalist. Results To test the wider applicability of the SGVH we compared 337 cytochrome oxidase I mitochondrial DNA and 268 nuclear tropomyosin DNA sequenced fragments derived from two co-distributed Laelaps mite species and compared the data to 294 COI mtDNA sequences derived from the respective hosts Rhabdomys dilectus, R. bechuanae, Mastomys coucha and M. natalensis. In support of the SGVH, the generalist L. muricola was characterized by a high mtDNA haplotypic diversity of 0.97 (±0.00) and a low level of population differentiation (mtDNA Fst = 0.56, p < 0.05; nuDNA Fst = 0.33, P < 0.05) while the specialist L. giganteus was overall characterized by a lower haplotypic diversity of 0.77 (±0.03) and comparatively higher levels of population differentiation (mtDNA Fst = 0.87, P < 0.05; nuDNA Fst = 0.48, P < 0.05). When the two specialist L. giganteus lineages, which occur on two different Rhabdomys species, are respectively compared to the generalist parasite, L. muricola, the SGVH is not fully supported. One of the specialist L. giganteus species occurring on R. dilectus shows similar low levels of population differentiation (mtDNA Fst = 0.53, P < 0.05; nuDNA Fst = 0.12, P < 0.05) than that found for the generalist L. muricola. This finding can be correlated to differences in host dispersal: R. bechuanae populations are characterized by a differentiated mtDNA Fst of 0.79 (P < 0.05) while R. dilectus populations are less structured with a mtDNA Fst = 0.18 (P < 0.05). Conclusions These findings suggest that in ectoparasites, host specificity and the vagility of the host are both important drivers for parasite dispersal. It is proposed that the SGHV hypothesis should also incorporate reference to host dispersal since in our case only the specialist species who occur on less mobile hosts showed more subdivided population structure when compared to generalist species. Electronic supplementary material The online version of this article (10.1186/s12862-018-1245-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Conrad A Matthee
- Evolutionary Genomics Group, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, Western Cape Province, South Africa.
| | - Adriaan Engelbrecht
- Evolutionary Genomics Group, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, Western Cape Province, South Africa.,Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, Western Cape Province, South Africa.,Department of Biodiversity and Conservation Biology, University of the Western Cape, Cape Town, Western Cape Province, South Africa
| | - Sonja Matthee
- Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, Western Cape Province, South Africa
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Osten-Sacken N, Heddergott M, Schleimer A, Anheyer-Behmenburg HE, Runge M, Horsburgh GJ, Camp L, Nadler SA, Frantz AC. Similar yet different: co-analysis of the genetic diversity and structure of an invasive nematode parasite and its invasive mammalian host. Int J Parasitol 2017; 48:233-243. [PMID: 29102623 DOI: 10.1016/j.ijpara.2017.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/24/2017] [Accepted: 08/31/2017] [Indexed: 01/13/2023]
Abstract
Animal parasitic nematodes can cause serious diseases and their emergence in new areas can be an issue of major concern for biodiversity conservation and human health. Their ability to adapt to new environments and hosts is likely to be affected by their degree of genetic diversity, with gene flow between distinct populations counteracting genetic drift and increasing effective population size. The raccoon roundworm (Baylisascaris procyonis), a gastrointestinal parasite of the raccoon (Procyon lotor), has increased its global geographic range after being translocated with its host. The raccoon has been introduced multiple times to Germany, but not all its populations are infected with the parasite. While fewer introduced individuals may have led to reduced diversity in the parasite, admixture between different founder populations may have counteracted genetic drift and bottlenecks. Here, we analyse the population genetic structure of the roundworm and its raccoon host at the intersection of distinct raccoon populations infected with B. procyonis. We found evidence for two parasite clusters resulting from independent introductions. Both clusters exhibited an extremely low genetic diversity, suggesting small founding populations subjected to inbreeding and genetic drift with no, or very limited, genetic influx from population admixture. Comparison of the population genetic structures of both host and parasite suggested that the parasite spread to an uninfected raccoon founder population. On the other hand, an almost perfect match between cluster boundaries also suggested that the population genetic structure of B. procyonis has remained stable since its introduction, mirroring that of its raccoon host.
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Affiliation(s)
- Natalia Osten-Sacken
- Musée National d, Histoire Naturelle, 25 rue Muenster, L-2160 Luxembourg, Luxembourg; Fondation Faune-Flore, 25 rue Muenster, L-2160 Luxembourg, Luxembourg
| | - Mike Heddergott
- Musée National d, Histoire Naturelle, 25 rue Muenster, L-2160 Luxembourg, Luxembourg
| | - Anna Schleimer
- Musée National d, Histoire Naturelle, 25 rue Muenster, L-2160 Luxembourg, Luxembourg
| | - Helena E Anheyer-Behmenburg
- Lower Saxony State Office for Consumer Protection and Food Safety, Food and Veterinary Institute Braunschweig/Hannover, Eintrachtweg 17, D-30173 Hannover, Germany
| | - Martin Runge
- Lower Saxony State Office for Consumer Protection and Food Safety, Food and Veterinary Institute Braunschweig/Hannover, Eintrachtweg 17, D-30173 Hannover, Germany
| | - Gavin J Horsburgh
- NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Lauren Camp
- Department of Entomology and Nematology, University of California, One Shields Avenue, Davis, CA 95616-8668, USA
| | - Steven A Nadler
- Department of Entomology and Nematology, University of California, One Shields Avenue, Davis, CA 95616-8668, USA
| | - Alain C Frantz
- Musée National d, Histoire Naturelle, 25 rue Muenster, L-2160 Luxembourg, Luxembourg.
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Correa AC, De Meeûs T, Dreyfuss G, Rondelaud D, Hurtrez-Boussès S. Galba truncatula and Fasciola hepatica: Genetic costructures and interactions with intermediate host dispersal. INFECTION GENETICS AND EVOLUTION 2017; 55:186-194. [PMID: 28917540 DOI: 10.1016/j.meegid.2017.09.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 09/12/2017] [Accepted: 09/12/2017] [Indexed: 12/07/2022]
Abstract
Antagonistic interactions between hosts and parasites are key structuring forces in natural populations. Demographic factors like extinction, migration and the effective population size shape host-parasite metapopulational dynamics. Therefore, to understand the evolution of host-parasite systems it is necessary to study the distribution of the genetic variation of both entities simultaneously. In this paper, we investigate the population genetics co-structure of parasites and hosts within a metapopulation of the liver fluke, Fasciola hepatica, and two of its intermediate hosts, the main intermediate host in Europe, Galba truncatula, and a new intermediate host, Omphiscola glabra, in Central France. Our results reveal an absence of specificity of flukes as regard to the two alternative hosts though O. glabra shows higher prevalence of F. hepatica. Host and parasites displayed contrasting population genetics structure with very small, highly inbred (selfing) and strongly isolated G. truncatula populations and much bigger, panmictic and more dispersive F. hepatica. This could indicate a local adaptation of the parasite and a local maladaptation of the host. We also unveil a parasite-mediated biased population genetics structure suggesting that infected G. truncatula disperse more; have higher dispersal survival than uninfected snails or, more likely, that immigrant snails are infected more often than local snails (local parasites are less adapted to local hosts). Finally, an absence, or at least an ambiguous signature of isolation by distance was observed in both host and parasite population. A very weak migration rate for G. truncatula provides a reasonable explanation for this ambiguous result. Alternatively, smaller sample sizes combined with modest migration rates might explain the difficulties to unveil the signal in F. hepatica.
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Affiliation(s)
- Ana C Correa
- Mivegec UMR UM, CNRS 5290 - IRD 224 Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, Centre IRD, BP 64501, 34394 Montpellier Cedex 5, France
| | - Thierry De Meeûs
- IRD, UMR Interactions hôtes - vecteurs - parasites dans les infections par des trypanosomatidae - (Intertryp) UMR IRD 177, CIRAD 17, TA A-17/G, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France.
| | - Gilles Dreyfuss
- Inserm 1094, Facultés de Médecine et de Pharmacie, Limoges, 2 Rue du Docteur Raymond Marcland, 87025 Limoges, France
| | - Daniel Rondelaud
- Inserm 1094, Facultés de Médecine et de Pharmacie, Limoges, 2 Rue du Docteur Raymond Marcland, 87025 Limoges, France
| | - Sylvie Hurtrez-Boussès
- Mivegec UMR UM, CNRS 5290 - IRD 224 Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, Centre IRD, BP 64501, 34394 Montpellier Cedex 5, France; Département de Biologie-Ecologie, Faculté des Sciences, Université Montpellier, 34095 Montpellier Cedex 5, France
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Signatures of mito-nuclear discordance in Schistosoma turkestanicum indicate a complex evolutionary history of emergence in Europe. Parasitology 2017; 144:1752-1762. [PMID: 28747240 DOI: 10.1017/s0031182017000920] [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: 01/03/2023]
Abstract
High levels of molecular diversity were identified in mitochondrial cytochrome c oxidase (cox1) gene sequences of Schistosoma turkestanicum from Hungary. These cox1 sequences were all specific to Hungary which contrasted with the low levels of diversity seen in the nuclear internal transcribed spacer region (ITS) sequences, the majority of which were shared between China and Iran isolates. Measures of within and between host molecular variation within S. turkestanicum showed there to be substantial differences in molecular diversity, with cox1 being significantly more diverse than the ITS. Measures of haplotype frequencies revealed that each host contained its own subpopulation of genetically unique parasites with significant levels of differentiation. Pairwise mismatch analysis of cox1 sequences indicated S. turkestanicum populations to have a bimodal pairwise difference distribution and to be stable unlike the ITS sequences, which appeared to have undergone a recent population expansion event. Positive selection was also detected in the cox1 sequences, and biochemical modelling of the resulting protein illustrated significant mutational events causing an alteration to the isoelectric point of the cox1 protein, potentially altering metabolism. The evolutionary signature from the cox1 indicates local adaptation and long establishment of S. turkestanicum in Hungary with continual introgression of nuclear genes from Asian isolates. These processes have led to the occurrence of mito-nuclear discordance in a schistosome population.
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Abstract
Hairworms (Nematomorpha) are a little-known group of parasites, and despite having been represented in the taxonomic literature for over a century, the implementation of molecular genetics in studies of hairworm ecology and evolution lags behind that of other parasitic taxa. In this study, we characterize the genetic diversity of the New Zealand nematomorph fauna and test for genetic structure within the most widespread species found. We provide new mitochondrial and nuclear ribosomal sequence data for three previously described species from New Zealand: Gordius paranensis, Parachordodes diblastus and Euchordodes nigromaculatus. We also present genetic data on a previously reported but undescribed Gordius sp., as well as data from specimens of a new Gordionus sp., a genus new for New Zealand. Phylogenetic analyses of CO1 and nuclear rDNA regions correspond with morphological classification based on scanning electron microscopy, and demonstrate paraphyly of the genus Gordionus and the potential for cryptic species within G. paranensis. Population-level analyses of E. nigromaculatus showed no genetic differentiation among sampling locations across the study area, in contrast to previously observed patterns in known and likely definitive hosts. Taken together, this raises the possibility that factors such as definitive host specificity, intermediate host movement, and passive dispersal of eggs and larvae may influence host-parasite population co-structure in hairworms.
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Shortt JA, Card DC, Schield DR, Liu Y, Zhong B, Castoe TA, Carlton EJ, Pollock DD. Whole Genome Amplification and Reduced-Representation Genome Sequencing of Schistosoma japonicum Miracidia. PLoS Negl Trop Dis 2017; 11:e0005292. [PMID: 28107347 PMCID: PMC5287463 DOI: 10.1371/journal.pntd.0005292] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 02/01/2017] [Accepted: 12/29/2016] [Indexed: 11/18/2022] Open
Abstract
Background In areas where schistosomiasis control programs have been implemented, morbidity and prevalence have been greatly reduced. However, to sustain these reductions and move towards interruption of transmission, new tools for disease surveillance are needed. Genomic methods have the potential to help trace the sources of new infections, and allow us to monitor drug resistance. Large-scale genotyping efforts for schistosome species have been hindered by cost, limited numbers of established target loci, and the small amount of DNA obtained from miracidia, the life stage most readily acquired from humans. Here, we present a method using next generation sequencing to provide high-resolution genomic data from S. japonicum for population-based studies. Methodology/Principal Findings We applied whole genome amplification followed by double digest restriction site associated DNA sequencing (ddRADseq) to individual S. japonicum miracidia preserved on Whatman FTA cards. We found that we could effectively and consistently survey hundreds of thousands of variants from 10,000 to 30,000 loci from archived miracidia as old as six years. An analysis of variation from eight miracidia obtained from three hosts in two villages in Sichuan showed clear population structuring by village and host even within this limited sample. Conclusions/Significance This high-resolution sequencing approach yields three orders of magnitude more information than microsatellite genotyping methods that have been employed over the last decade, creating the potential to answer detailed questions about the sources of human infections and to monitor drug resistance. Costs per sample range from $50-$200, depending on the amount of sequence information desired, and we expect these costs can be reduced further given continued reductions in sequencing costs, improvement of protocols, and parallelization. This approach provides new promise for using modern genome-scale sampling to S. japonicum surveillance, and could be applied to other schistosome species and other parasitic helminthes. Schistosomiasis is a devastating tropical disease that affects more than 200 million people worldwide. Over the past several decades, transmission control strategies implemented in China have reduced the prevalence and morbidity of Schistosoma japonicum in many areas. Infections still persist, however, and it is therefore of great interest to determine the sources of recurring infections. Genetic analysis is a promising means to achieve this. Towards this aim, we conducted a pilot study to assess the feasibility of using high-throughput sequencing to assess the geographic distribution of schistosome genetic variants. Because DNA yields from miracidia, the most easily accessible life stage, are insufficient for high throughput sequencing, we first employed whole genome amplification to obtain sufficient quantities of DNA. We then employed a technique that reproducibly sequences the same fraction of a genome across numerous samples. We successfully sequenced 6-year old S. japonicum samples from Sichuan Province, China, easily and economically identifying tens of thousands of variable loci, a sufficient number to discriminate fine-scale population structure. Further population sampling will help answer important questions concerning the persistence of infections, the sources of new infections, and whether parasite populations have undergone incipient evolution of drug resistance.
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Affiliation(s)
- Jonathan A. Shortt
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Daren C. Card
- Department of Biology, University of Texas Arlington, Arlington, TX, United States of America
| | - Drew R. Schield
- Department of Biology, University of Texas Arlington, Arlington, TX, United States of America
| | - Yang Liu
- Institute of Parasitic Disease, Sichuan Center for Disease Control and Prevention, Chengdu, The People’s Republic of China
| | - Bo Zhong
- Institute of Parasitic Disease, Sichuan Center for Disease Control and Prevention, Chengdu, The People’s Republic of China
| | - Todd A. Castoe
- Department of Biology, University of Texas Arlington, Arlington, TX, United States of America
| | - Elizabeth J. Carlton
- Department of Environmental and Occupational Health, University of Colorado, Colorado School of Public Health, Aurora, CO, United States of America
| | - David D. Pollock
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, United States of America
- * E-mail:
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20
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Genotype-specific interactions between parasitic arthropods. Heredity (Edinb) 2016; 118:260-265. [PMID: 27759078 DOI: 10.1038/hdy.2016.90] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 11/08/2022] Open
Abstract
Despite the ubiquity of coinfection, we know little of the effects of intra-specific genetic variability on coinfection by distinct parasite species. Here we test the hypothesis that parasite multiplication depends on the combination of parasite genotypes that coinfect the host (that is Genotype.parasite × Genotype.parasite interaction). To that aim, we infected tomato leaves with the ecto-parasitic mites Tetranychus urticae and Tetranychus evansi. We tested all possible combinations between four T. urticae and two T. evansi populations sampled on different hosts or localities. There was no universal (that is genotype-independent) effect of coinfection on mite multiplication; in many cases the two species had no effect on each other. However, several combinations of T. evansi and T. urticae populations led to elevated T. evansi numbers. Similarly, T. urticae reproduction largely depended on the interaction between T. urticae and T. evansi populations. This evidence for genotype-by-genotype interaction between coinfecting parasites indicates that the effect of coinfection on parasite epidemiology and evolution may vary in space according to the genetic composition of local parasite populations; it further suggests the possibility of coevolution between parasites species that share the same hosts.
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21
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Vergilino R, Leung C, Angers B. Inconsistent phylogeographic pattern between a sperm dependent fish and its host: in situ hybridization vs dispersal. BMC Evol Biol 2016; 16:183. [PMID: 27600616 PMCID: PMC5012089 DOI: 10.1186/s12862-016-0754-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 08/24/2016] [Indexed: 11/10/2022] Open
Abstract
Background Co-dispersal of sperm-dependent hybrids and their sexual relatives is expected to result in consistent spatial patterns between assemblages of hybrids and genetic structure of parental species. However, local hybridization events may blur this signal as assemblages could be organized under different connectivity constraints. This study aims at testing the hypothesis of local hybridization events by comparing the assemblage of hybrid fish Chrosomus eos-neogaeus to the genetic diversity of one of its parental species, Chrosomus eos. Results An extensive survey performed on a total of 132 sites located in two regions of Southern Quebec (West-Qc and East-Qc) revealed a distinct organization of hybrid lineages. One of the six hybrid lineages detected in West-Qc is widespread throughout this region resulting in a low α-diversity (1.38) and β-diversity (4.35). On the other hand, 36 hybrid lineages were detected in East-Qc and displayed narrow geographic distributions leading to a high α-diversity (2.30) and β-diversity (15.68). In addition, the C. eos multilocus haplotype of several of these hybrids is assigned to their respective sympatric C. eos population. Finally, contrasting with hybrids, the paternal species C. eos displayed a higher ρST in West-Qc (0.2300) than in East-Qc (0.0734). Conclusion The unusually high diversity of hybrid lineages in East-Qc as well as the spatial organization and the close genetic relationship with C. eos sympatric populations support the hypothesis that multiple hybridization events occurred in situ. These findings coupled to the near absence of the maternal species Chrosomus neogeaus suggest that the decline of this species could be the trigger event at the origin of the high rates of spontaneous hybridization in this region. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0754-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Roland Vergilino
- Department of biological sciences, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada
| | - Christelle Leung
- Department of biological sciences, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada
| | - Bernard Angers
- Department of biological sciences, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada.
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Rahn AK, Krassmann J, Tsobanidis K, MacColl ADC, Bakker TCM. Strong neutral genetic differentiation in a host, but not in its parasite. INFECTION GENETICS AND EVOLUTION 2016; 44:261-271. [PMID: 27421211 DOI: 10.1016/j.meegid.2016.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/08/2016] [Accepted: 07/11/2016] [Indexed: 11/28/2022]
Abstract
The genetic diversity and population structure of a parasite with a complex life cycle generally depends on the dispersal by its most motile host. Given that high gene flow is assumed to hinder local adaptation, this can impose significant constraints on a parasite's potential to adapt to local environmental conditions, intermediate host populations, and ultimately to host-parasite coevolution. Here, we aimed to examine the population genetic basis for local host-parasite interactions between the eye fluke Diplostomum lineage 6, a digenean trematode with a multi-host life cycle (including a snail, a fish, and a bird) and its second intermediate host, the three-spined stickleback Gasterosteus aculeatus L. We developed the first microsatellite primers for D. lineage 6 and used them together with published stickleback markers to analyse host and parasite population structures in 19 freshwater lakes, which differ in their local environmental characteristics regarding water chemistry and Diplostomum abundance. Our analyses suggest that one parasite population successfully infects a range of genetically differentiated stickleback populations. The lack of neutral genetic differentiation in D. lineage 6, which could be attributed to the motility of the parasite's definitive host as well as its life cycle characteristics, makes local host-parasite co-adaptations seem more likely on a larger geographical scale than among the lakes of our study site. Our study provides a suitable background for future studies in this system and the first microsatellite primers for a widespread fish parasite.
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Affiliation(s)
- Anna K Rahn
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121 Bonn, Germany.
| | - Johannes Krassmann
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121 Bonn, Germany
| | - Kostas Tsobanidis
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121 Bonn, Germany
| | - Andrew D C MacColl
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Theo C M Bakker
- Institute for Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, 53121 Bonn, Germany
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Strobel HM, Alda F, Sprehn CG, Blum MJ, Heins DC. Geographic and host-mediated population genetic structure in a cestode parasite of the three-spined stickleback. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12826] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Hannah M. Strobel
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA 70118 USA
| | - Fernando Alda
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA 70118 USA
- Tulane-Xavier Center for Bioenvironmental Research; Tulane University; New Orleans LA 70118 USA
| | - C. Grace Sprehn
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA 70118 USA
| | - Michael J. Blum
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA 70118 USA
- Tulane-Xavier Center for Bioenvironmental Research; Tulane University; New Orleans LA 70118 USA
| | - David C. Heins
- Department of Ecology and Evolutionary Biology; Tulane University; New Orleans LA 70118 USA
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Echaubard P, Sripa B, Mallory FF, Wilcox BA. The role of evolutionary biology in research and control of liver flukes in Southeast Asia. INFECTION GENETICS AND EVOLUTION 2016; 43:381-97. [PMID: 27197053 DOI: 10.1016/j.meegid.2016.05.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 05/12/2016] [Accepted: 05/14/2016] [Indexed: 01/04/2023]
Abstract
Stimulated largely by the availability of new technology, biomedical research at the molecular-level and chemical-based control approaches arguably dominate the field of infectious diseases. Along with this, the proximate view of disease etiology predominates to the exclusion of the ultimate, evolutionary biology-based, causation perspective. Yet, historically and up to today, research in evolutionary biology has provided much of the foundation for understanding the mechanisms underlying disease transmission dynamics, virulence, and the design of effective integrated control strategies. Here we review the state of knowledge regarding the biology of Asian liver Fluke-host relationship, parasitology, phylodynamics, drug-based interventions and liver Fluke-related cancer etiology from an evolutionary biology perspective. We consider how evolutionary principles, mechanisms and research methods could help refine our understanding of clinical disease associated with infection by Liver Flukes as well as their transmission dynamics. We identify a series of questions for an evolutionary biology research agenda for the liver Fluke that should contribute to an increased understanding of liver Fluke-associated diseases. Finally, we describe an integrative evolutionary medicine approach to liver Fluke prevention and control highlighting the need to better contextualize interventions within a broader human health and sustainable development framework.
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Affiliation(s)
- Pierre Echaubard
- WHO Collaborating Centre for Research and Control of Opisthorchiasis, Tropical Disease Research laboratory, Department of Experimental Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Biology, Laurentian University, Sudbury, Ontario P3E 2C6, Canada; Global Health Asia, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
| | - Banchob Sripa
- WHO Collaborating Centre for Research and Control of Opisthorchiasis, Tropical Disease Research laboratory, Department of Experimental Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Liver Fluke and Cholangiocarcinoma Research Center, Department of Parasitology, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Frank F Mallory
- Department of Biology, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | - Bruce A Wilcox
- Global Health Asia, Faculty of Public Health, Mahidol University, Bangkok, Thailand; Cummings School of Veterinary Medicine, Tufts University, Medford, MA 02155, USA
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Genetic diversity and population structure of Synthesium pontoporiae (Digenea, Brachycladiidae) linked to its definitive host stocks, the endangered Franciscana dolphin, Pontoporia blainvillei (Pontoporiidae) off the coast of Brazil and Argentina. J Helminthol 2016; 89:19-27. [PMID: 26262593 DOI: 10.1017/s0022149x13000540] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Pontoporia blainvillei (Gervais and d'Orbigny, 1844) is an endangered small cetacean endemic to South America with four Franciscana Management Areas (FMA) recognized as different population stocks. The role of the intestinal parasite Synthesium pontoporiae (Digenea: Brachycladiidae) as a possible biological marker to differentiate P. blainvillei stocks was evaluated using nuclear and mitochondrial DNA markers. Internal transcribed sequence 1 and 2 (ITS1 and ITS2) regions of S. pontoporiae did not show intraspecific variability. The mitochondrial NADH dehydrogenase subunit 3 (ND3) and cytochrome oxidase subunit I (COI) gene sequences suggested lack of population structure in S. pontoporiae and population expansion. The apparent panmixia of S. pontoporiae may be due to the high mobility of one or more of its intermediary hosts. Alternatively, it may be due to the small sample size. This result is incongruent with the previously proposed FMA.
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Mazé-Guilmo E, Blanchet S, McCoy KD, Loot G. Host dispersal as the driver of parasite genetic structure: a paradigm lost? Ecol Lett 2016; 19:336-47. [DOI: 10.1111/ele.12564] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/07/2015] [Accepted: 11/26/2015] [Indexed: 01/21/2023]
Affiliation(s)
- Elise Mazé-Guilmo
- Centre National de la Recherche Scientifique (CNRS); Station d'Ecologie Expérimentale du CNRS à Moulis; USR 2936; F-09200 Moulis France
| | - Simon Blanchet
- Centre National de la Recherche Scientifique (CNRS); Station d'Ecologie Expérimentale du CNRS à Moulis; USR 2936; F-09200 Moulis France
- Centre National de la Recherche Scientifique (CNRS); Université Paul Sabatier, École Nationale de Formation Agronomique (ENFA); UMR5174 EDB (Laboratoire Évolution & Diversité Biologique); 118 route de Narbonne F-31062 Toulouse Cedex 4 France
| | - Karen D. McCoy
- Centre National de la Recherche Scientifique (CNRS); Institut de Recherche pour le Développement (IRD); Université de Montpellier; UMR 5290 MIVEGEC; 911 Avenue Agropolis F-34394 Montpellier France
| | - Géraldine Loot
- Centre National de la Recherche Scientifique (CNRS); Station d'Ecologie Expérimentale du CNRS à Moulis; USR 2936; F-09200 Moulis France
- Université de Toulouse; UPS; UMR 5174 (EDB); 118 route de Narbonne F-31062 Toulouse Cedex 4 France
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Penczykowski RM, Laine A, Koskella B. Understanding the ecology and evolution of host-parasite interactions across scales. Evol Appl 2016; 9:37-52. [PMID: 27087838 PMCID: PMC4780374 DOI: 10.1111/eva.12294] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/18/2015] [Indexed: 12/19/2022] Open
Abstract
Predicting the emergence, spread and evolution of parasites within and among host populations requires insight to both the spatial and temporal scales of adaptation, including an understanding of within-host up through community-level dynamics. Although there are very few pathosystems for which such extensive data exist, there has been a recent push to integrate studies performed over multiple scales or to simultaneously test for dynamics occurring across scales. Drawing on examples from the literature, with primary emphasis on three diverse host-parasite case studies, we first examine current understanding of the spatial structure of host and parasite populations, including patterns of local adaptation and spatial variation in host resistance and parasite infectivity. We then explore the ways to measure temporal variation and dynamics in host-parasite interactions and discuss the need to examine change over both ecological and evolutionary timescales. Finally, we highlight new approaches and syntheses that allow for simultaneous analysis of dynamics across scales. We argue that there is great value in examining interplay among scales in studies of host-parasite interactions.
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Affiliation(s)
- Rachel M. Penczykowski
- Department of BiosciencesMetapopulation Research CentreUniversity of HelsinkiHelsinkiFinland
| | - Anna‐Liisa Laine
- Department of BiosciencesMetapopulation Research CentreUniversity of HelsinkiHelsinkiFinland
| | - Britt Koskella
- BiosciencesUniversity of ExeterTremoughUK
- Integrative BiologyUniversity of CaliforniaBerkeleyUSA
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Lagrue C, Joannes A, Poulin R, Blasco-Costa I. Genetic structure and host-parasite co-divergence: evidence for trait-specific local adaptation. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12722] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Clément Lagrue
- Department of Zoology; University of Otago; Dunedin New Zealand
| | - Arnaud Joannes
- Department of Zoology; University of Otago; Dunedin New Zealand
| | - Robert Poulin
- Department of Zoology; University of Otago; Dunedin New Zealand
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Keogh CL, Sanderson ME, Byers JE. Local adaptation to parasite selective pressure: comparing three congeneric co-occurring hosts. Oecologia 2015; 180:137-47. [DOI: 10.1007/s00442-015-3461-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 09/20/2015] [Indexed: 02/05/2023]
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Brown GP, Kelehear C, Pizzatto L, Shine R. The impact of lungworm parasites on rates of dispersal of their anuran host, the invasive cane toad. Biol Invasions 2015. [DOI: 10.1007/s10530-015-0993-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Modelling the effects of mass drug administration on the molecular epidemiology of schistosomes. ADVANCES IN PARASITOLOGY 2015; 87:293-327. [PMID: 25765198 DOI: 10.1016/bs.apar.2014.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
As national governments scale up mass drug administration (MDA) programs aimed to combat neglected tropical diseases (NTDs), novel selection pressures on these parasites increase. To understand how parasite populations are affected by MDA and how to maximize the success of control programmes, it is imperative for epidemiological, molecular and mathematical modelling approaches to be combined. Modelling of parasite population genetic and genomic structure, particularly of the NTDs, has been limited through the availability of only a few molecular markers to date. The landscape of infectious disease research is being dramatically reshaped by next-generation sequencing technologies and our understanding of how repeated selective pressures are shaping parasite populations is radically altering. Genomics can provide high-resolution data on parasite population structure, and identify how loci may contribute to key phenotypes such as virulence and/or drug resistance. We discuss the incorporation of genetic and genomic data, focussing on the recently sequenced Schistosoma spp., into novel mathematical transmission models to inform our understanding of the impact of MDA and other control methods. We summarize what is known to date, the models that exist and how population genetics has given us an understanding of the effects of MDA on the parasites. We consider how genetic and genomic data have the potential to shape future research, highlighting key areas where data are lacking, and how future molecular epidemiology knowledge can aid understanding of transmission dynamics and the effects of MDA, ultimately informing public health policy makers of the best interventions for NTDs.
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Witsenburg F, Clément L, López-Baucells A, Palmeirim J, Pavlinić I, Scaravelli D, Ševčík M, Dutoit L, Salamin N, Goudet J, Christe P. How a haemosporidian parasite of bats gets around: the genetic structure of a parasite, vector and host compared. Mol Ecol 2015; 24:926-40. [PMID: 25641066 DOI: 10.1111/mec.13071] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/20/2014] [Accepted: 01/02/2015] [Indexed: 01/10/2023]
Abstract
Parasite population structure is often thought to be largely shaped by that of its host. In the case of a parasite with a complex life cycle, two host species, each with their own patterns of demography and migration, spread the parasite. However, the population structure of the parasite is predicted to resemble only that of the most vagile host species. In this study, we tested this prediction in the context of a vector-transmitted parasite. We sampled the haemosporidian parasite Polychromophilus melanipherus across its European range, together with its bat fly vector Nycteribia schmidlii and its host, the bent-winged bat Miniopterus schreibersii. Based on microsatellite analyses, the wingless vector, and not the bat host, was identified as the least structured population and should therefore be considered the most vagile host. Genetic distance matrices were compared for all three species based on a mitochondrial DNA fragment. Both host and vector populations followed an isolation-by-distance pattern across the Mediterranean, but not the parasite. Mantel tests found no correlation between the parasite and either the host or vector populations. We therefore found no support for our hypothesis; the parasite population structure matched neither vector nor host. Instead, we propose a model where the parasite's gene flow is represented by the added effects of host and vector dispersal patterns.
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Affiliation(s)
- F Witsenburg
- Department of Ecology and Evolution, University of Lausanne, Biophore, Lausanne, CH-1015, Switzerland
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33
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Mitochondrial phylogeography of the black rat supports a single invasion of the western Mediterranean basin. Biol Invasions 2015. [DOI: 10.1007/s10530-015-0842-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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34
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Mutuku MW, Dweni CK, Mwangi M, Kinuthia JM, Mwangi IN, Maina GM, Agola LE, Zhang SM, Maranga R, Loker ES, Mkoji GM. Field-derived Schistosoma mansoni and Biomphalaria pfeifferi in Kenya: a compatible association characterized by lack of strong local adaptation, and presence of some snails able to persistently produce cercariae for over a year. Parasit Vectors 2014; 7:533. [PMID: 25425455 PMCID: PMC4253995 DOI: 10.1186/s13071-014-0533-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 11/11/2014] [Indexed: 11/29/2022] Open
Abstract
Background Schistosoma mansoni is widely distributed in sub-Saharan Africa with Biomphalaria pfeifferi being its most widespread and important snail intermediate host. Few studies have examined the compatibility of field-derived B. pfeifferi snails with S. mansoni miracidia derived from human hosts. We investigated compatibility (as defined by shedding of cercariae following exposure to miracidia) of two isolates of S. mansoni from school children from Asao (western Kenya) and Mwea (central Kenya) with B. pfeifferi collected directly from Asao stream or the Mwea rice fields. Methods We exposed snails from both regions to four different doses of miracidia (1, 5, 10 and 25) from sympatric or allopatric S. mansoni, and maintained them in a shaded, screened out-of-doors rearing facility in Kisian, in western Kenya. Both snail survival and the number of snails that became infected were monitored weekly. This was done for 25 weeks post-exposure (PE). Those infected snails which survived beyond this period were monitored until they all died. Results Although overall survival of Mwea snails maintained in western Kenya was generally low, both sympatric and allopatric combinations of parasites and snails exhibited high compatibility (approximately 50% at a dose of one miracidium per snail), with an increase in infection rates as the miracidial dose was increased (P < 0.002). Schistosomes were no more compatible with sympatric than allopatric snails, nor were snails less compatible with sympatric than allopatric schistosomes. Snail mortality increased significantly with dose of miracidia (P < 0.05). Approximately 3% of Asao snails exposed to a low dose of sympatric miracidia (1 or 5) continued to shed cercariae for as long as 58 weeks post exposure. Conclusions There were no significant local adaptation effects for either schistosomes or snails. Also, the existence of “super-survivor” snails is noteworthy for its implications for current control initiatives that mostly rely on mass drug administration (MDA). Long-term shedders could provide an ongoing source of cercariae to initiate human infections for many months, suggesting care is required in considering how human MDA treatments are timed. Future control programs should incorporate means to eliminate infected snails to complement chemotherapy interventions in controlling schistosomiasis. Electronic supplementary material The online version of this article (doi:10.1186/s13071-014-0533-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martin W Mutuku
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya.
| | - Celestine K Dweni
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya.
| | - Moses Mwangi
- Centre for Public Health Research, KEMRI, P.O Box 20752-00200, Nairobi, Kenya.
| | - Joseph M Kinuthia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya.
| | - Ibrahim N Mwangi
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya.
| | - Geoffrey M Maina
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya.
| | - Lelo E Agola
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya.
| | - Si-Ming Zhang
- Center for Evolutionary and Theoretical Immunology, Department of Biology, and Parasitology Division, Museum of Southwestern Biology, University of New Mexico, Albuquerque, 87131, U.S.A.
| | - Rosebella Maranga
- Department of Zoology, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200, Nairobi, Kenya.
| | - Eric S Loker
- Center for Evolutionary and Theoretical Immunology, Department of Biology, and Parasitology Division, Museum of Southwestern Biology, University of New Mexico, Albuquerque, 87131, U.S.A.
| | - Gerald M Mkoji
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya.
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Chelomina GN, Tatonova YV, Hung NM, Ngo HD. Genetic diversity of the Chinese liver fluke Clonorchis sinensis from Russia and Vietnam. Int J Parasitol 2014; 44:795-810. [DOI: 10.1016/j.ijpara.2014.06.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/01/2014] [Accepted: 06/02/2014] [Indexed: 11/24/2022]
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Ponce-Terashima R, Koskey AM, Reis MG, McLellan SL, Blanton RE. Sources and distribution of surface water fecal contamination and prevalence of schistosomiasis in a Brazilian village. PLoS Negl Trop Dis 2014; 8:e3186. [PMID: 25275467 PMCID: PMC4183440 DOI: 10.1371/journal.pntd.0003186] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 08/13/2014] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND The relationship between poor sanitation and the parasitic infection schistosomiasis is well-known, but still rarely investigated directly and quantitatively. In a Brazilian village we correlated the spatial concentration of human fecal contamination of its main river and the prevalence of schistosomiasis. METHODS We validated three bacterial markers of contamination in this population by high throughput sequencing of the 16S rRNA gene and qPCR of feces from local residents. The qPCR of genetic markers from the 16S rRNA gene of Bacteroides-Prevotella group, Bacteroides HF8 cluster, and Lachnospiraceae Lachno2 cluster as well as sequencing was performed on georeferenced samples of river water. Ninety-six percent of residents were examined for schistosomiasis. FINDINGS Sequence of 16S rRNA DNA from stool samples validated the relative human specificity of the HF8 and Lachno 2 fecal indicators compared to animals. The concentration of fecal contamination increased markedly along the river as it passed an increasing proportion of the population on its way downstream as did the sequence reads from bacterial families associated with human feces. Lachnospiraceae provided the most robust signal of human fecal contamination. The prevalence of schistosomiasis likewise increased downstream. Using a linear regression model, a significant correlation was demonstrated between the prevalence of S. mansoni infection and local concentration of human fecal contamination based on the Lachnospiraceae Lachno2 cluster (r2 0.53) as compared to the correlation with the general fecal marker E. coli (r2 0.28). INTERPRETATION Fecal contamination in rivers has a downstream cumulative effect. The transmission of schistosomiasis correlates with very local factors probably resulting from the distribution of human fecal contamination, the limited movement of snails, and the frequency of water contact near the home. In endemic regions, the combined use of human associated bacterial markers and GIS analysis can quantitatively identify areas with risk for schistosomiasis as well as assess the efficacy of sanitation and environmental interventions for prevention.
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Affiliation(s)
- Rafael Ponce-Terashima
- Mercer University School of Medicine, Macon, Georgia, United States of America
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Amber M. Koskey
- School of Freshwater Sciences, Great Lakes Water Institute, University of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Mitermayer G. Reis
- Laboratory of Pathology and Molecular Biology, Gonçalo Moniz Research Center, Oswaldo Cruz Foundation, Salvador, Bahia, Brazil
| | - Sandra L. McLellan
- School of Freshwater Sciences, Great Lakes Water Institute, University of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Ronald E. Blanton
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
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Auld SKJR, Tinsley MC. The evolutionary ecology of complex lifecycle parasites: linking phenomena with mechanisms. Heredity (Edinb) 2014; 114:125-32. [PMID: 25227255 DOI: 10.1038/hdy.2014.84] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 07/09/2014] [Accepted: 08/12/2014] [Indexed: 11/09/2022] Open
Abstract
Many parasitic infections, including those of humans, are caused by complex lifecycle parasites (CLPs): parasites that sequentially infect different hosts over the course of their lifecycle. CLPs come from a wide range of taxonomic groups-from single-celled bacteria to multicellular flatworms-yet share many common features in their life histories. Theory tells us when CLPs should be favoured by selection, but more empirical studies are required in order to quantify the costs and benefits of having a complex lifecycle, especially in parasites that facultatively vary their lifecycle complexity. In this article, we identify ecological conditions that favour CLPs over their simple lifecycle counterparts and highlight how a complex lifecycle can alter transmission rate and trade-offs between growth and reproduction. We show that CLPs participate in dynamic host-parasite coevolution, as more mobile hosts can fuel CLP adaptation to less mobile hosts. Then, we argue that a more general understanding of the evolutionary ecology of CLPs is essential for the development of effective frameworks to manage the many diseases they cause. More research is needed identifying the genetics of infection mechanisms used by CLPs, particularly into the role of gene duplication and neofunctionalisation in lifecycle evolution. We propose that testing for signatures of selection in infection genes will reveal much about how and when complex lifecycles evolved, and will help quantify complex patterns of coevolution between CLPs and their various hosts. Finally, we emphasise four key areas where new research approaches will provide fertile opportunities to advance this field.
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Affiliation(s)
- S K J R Auld
- Division of Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, UK
| | - M C Tinsley
- Division of Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, UK
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Djuikwo-Teukeng F, Da Silva A, Njiokou F, Kamgang B, Ekobo AS, Dreyfuss G. Significant population genetic structure of the Cameroonian fresh water snail, Bulinus globosus, (Gastropoda: Planorbidae) revealed by nuclear microsatellite loci analysis. Acta Trop 2014; 137:111-7. [PMID: 24751417 DOI: 10.1016/j.actatropica.2014.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 04/07/2014] [Accepted: 04/08/2014] [Indexed: 01/18/2023]
Abstract
In order to characterize the demographic traits and spatial structure of Cameroonians Bulinus globosus, intermediate host of Schistosoma haematobium, genetic structure of seven different populations, collected from the tropical zone, was studied using six polymorphic microsatellites. Intrapopulation genetic diversity ranged from 0.37 to 0.55. Interpopulation genetic diversity variation clearly illustrated their significant isolation due to distance with gene flow substantially limited to neighbouring populations. The effective population sizes (Ne) were relatively low (from 3.0 to 18.6), which supposes a high rate from which populations would lose their genetic diversity by drift. Analysis of genetic temporal variability indicated fluctuations of allelic frequencies (35 of 42 locus-population combinations, P<0.05) characteristic of stochastic demography, and this is reinforced by events of bottlenecks detected in all populations. These findings demonstrated that Cameroonian B. globosus were mixed-maters with some populations showing clear preference for outcrossing. These data also suggest that genetic drift and gene flow are the main factors shaping the genetic structure of studied populations.
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Selective and universal primers for trematode barcoding in freshwater snails. Parasitol Res 2014; 113:2535-40. [PMID: 24781022 DOI: 10.1007/s00436-014-3903-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 04/09/2014] [Indexed: 10/25/2022]
Abstract
Trematodes are significant pathogens of high medical, veterinary, and environmental importance. They are hard to isolate from their intermediate hosts, and their early life stages are difficult to identify morphologically. Therefore, primers were developed for trematodes to create a species barcoding system and allow selective PCR amplification in mixed samples. The specific oligonucleotide primer was universal for trematodes that infected several freshwater snail species in Israel. The diagnostic tool is based on the 18S rDNA gene. In contrast to morphological identification, trematode barcoding is rapid as it is based on a sequence of only 800 bp, and it classifies species accurately due to high polymorphism between conserved areas.
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Van den Broeck F, Meurs L, Raeymaekers JAM, Boon N, Dieye TN, Volckaert FAM, Polman K, Huyse T. Inbreeding within human Schistosoma mansoni: do host-specific factors shape the genetic composition of parasite populations? Heredity (Edinb) 2014; 113:32-41. [PMID: 24619176 DOI: 10.1038/hdy.2014.13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 01/09/2014] [Accepted: 01/17/2014] [Indexed: 11/09/2022] Open
Abstract
The size, structure and distribution of host populations are key determinants of the genetic composition of parasite populations. Despite the evolutionary and epidemiological merits, there has been little consideration of how host heterogeneities affect the evolutionary trajectories of parasite populations. We assessed the genetic composition of natural populations of the parasite Schistosoma mansoni in northern Senegal. A total of 1346 parasites were collected from 14 snail and 57 human hosts within three villages and individually genotyped using nine microsatellite markers. Human host demographic parameters (age, gender and village of residence) and co-infection with Schistosoma haematobium were documented, and S. mansoni infection intensities were quantified. F-statistics and clustering analyses revealed a random distribution (panmixia) of parasite genetic variation among villages and hosts, confirming the concept of human hosts as 'genetic mixing bowls' for schistosomes. Host gender and village of residence did not show any association with parasite genetics. Host age, however, was significantly correlated with parasite inbreeding and heterozygosity, with children being more infected by related parasites than adults. The patterns may be explained by (1) genotype-dependent 'concomitant immunity' that leads to selective recruitment of genetically unrelated worms with host age, and/or (2) the 'genetic mixing bowl' hypothesis, where older hosts have been exposed to a wider variety of parasite strains than children. The present study suggests that host-specific factors may shape the genetic composition of schistosome populations, revealing important insights into host-parasite interactions within a natural system.
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Affiliation(s)
- F Van den Broeck
- 1] Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Leuven, Belgium [2] Unit of Medical Helminthology, Institute of Tropical Medicine, Antwerp, Belgium
| | - L Meurs
- Unit of Medical Helminthology, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - N Boon
- 1] Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Leuven, Belgium [2] Unit of Medical Helminthology, Institute of Tropical Medicine, Antwerp, Belgium
| | - T N Dieye
- Laboratory of Bacteriology and Virology, Aristide Le Dantec University Hospital, Dakar, Senegal
| | - F A M Volckaert
- Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Leuven, Belgium
| | - K Polman
- Unit of Medical Helminthology, Institute of Tropical Medicine, Antwerp, Belgium
| | - T Huyse
- 1] Laboratory of Biodiversity and Evolutionary Genomics, University of Leuven, Leuven, Belgium [2] Unit of Medical Helminthology, Institute of Tropical Medicine, Antwerp, Belgium [3] Section Invertebrates, Royal Museum for Central Africa, Tervuren, Belgium
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Quan QM, Wang QX, Zhou XL, Li S, Yang XL, Zhu YG, Cheng Z. Comparative phylogenetic relationships and genetic structure of the caterpillar fungus Ophiocordyceps sinensis and its host insects inferred from multiple gene sequences. J Microbiol 2014; 52:99-105. [PMID: 24500473 DOI: 10.1007/s12275-014-3391-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/27/2013] [Accepted: 09/30/2013] [Indexed: 11/24/2022]
Abstract
Ophiocordyceps sinensis (Ascomycota: Ophiocordycipitaceae) is a native fungal parasite of Hepialidae caterpillars and one of the most economically important medicinal caterpillar fungi in China. However, little is known about the phylogenetic and evolutionary relationships between O. sinensis and its host insects. In this study, nuclear ITS and β-tubulin sequences from O. sinensis and mitochondrial COI, COII, and Cytb sequences from its hosts were analyzed across 33 populations sampled from five regions in China. Phylogenetically, both O. sinensis and its hosts were divided into three geographically correlated clades, and their phylogenies were congruent. Analysis of molecular variance and calculated coefficients of genetic differentiation revealed significant genetic divergence among the clades within both O. sinensis (F(ST)= 0.878, N(ST)=0.842) and its hosts (F(ST)=0.861, N(ST)=0.816). Estimated gene flow was very low for O. sinensis (Nm=0.04) and the host insects (Nm=0.04) among these three clades. Mantel tests demonstrated a significant correlation (P<0.01) between the genetic distances for O. sinensis and its hosts, as well as a significant association (P<0.05) between geographic and genetic distances in both. The similar phylogenetic relationships, geographic distributions, and genetic structure and differentiation between O. sinensis and its hosts imply that they have coevolved.
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Affiliation(s)
- Qing-Mei Quan
- School of Life Science and Technology, Tongji University, Shanghai, P. R. China
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Song R, Li WX, Wu SG, Zou H, Wang GT. Population genetic structure of the acanthocephalan Acanthosentis cheni in anadromous, freshwater, and landlocked stocks of its fish host, Coilia nasus. J Parasitol 2013; 100:193-7. [PMID: 24224788 DOI: 10.1645/12-144.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The acanthocephalan Acanthosentis cheni was found in anadromous, freshwater, and landlocked stocks of its fish host, Coilia nasus. To examine the genetic variations of the acanthocephalan among the 3 populations with the adaptation of the host to the freshwater, the genetic structure of the helminth was investigated in anadromous (Zhoushan and Chongming islands, and Anqing), freshwater (Anqing, Ezhou, and Poyang Lake), and landlocked (Tian'ezhou Reserve) populations by sequencing intergenic transcribed spacers (ITS) of the ribosomal RNA coding genes. Low Fst values and high gene flow were found among the 7 populations (Fst = 0.0135, P = 0.2723; Nm = 36.48) and the 3 ecotypes of Acanthosentis cheni (Fst = 0.0178, P = 0.1044; Nm = 27.67). On the other hand, significant genetic differentiation of the C. nasus host populations was detected between the upstream and downstream areas of Xiaogu Mountain (Fst = 0.1961, P = 0.0030; Nm = 2.05), which is the farthest location of spawning migration for C. nasus . However, the migration break of the fish host appeared not to cause significant genetic differentiation of A. cheni populations between the upper and lower reaches of Xiaogu Mountain. Other factors might promote genetic exchange of A. cheni populations such as dispersal of the intermediate host by flooding or other fish species serving as the definitive or paratenic hosts. In Anqing, nucleotide diversity of the acanthocephalan was highest in the freshwater population (0.0038) and lower in the anadromous population (0.0026). This suggested that new mutations may have occurred in the freshwater A. cheni population in Anqing when adapting to a freshwater environment.
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Affiliation(s)
- Rui Song
- * The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, and Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan 430072, China. Correspondence should be sent to:
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French MD, Churcher TS, Basáñez MG, Norton AJ, Lwambo NJ, Webster JP. Reductions in genetic diversity of Schistosoma mansoni populations under chemotherapeutic pressure: the effect of sampling approach and parasite population definition. Acta Trop 2013; 128:196-205. [PMID: 22440199 DOI: 10.1016/j.actatropica.2012.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 03/02/2012] [Accepted: 03/04/2012] [Indexed: 10/28/2022]
Abstract
Detecting potential changes in genetic diversity in schistosome populations following chemotherapy with praziquantel (PZQ) is crucial if we are to fully understand the impact of such chemotherapy with respect to the potential emergence of resistance and/or other evolutionary outcomes of interventions. Doing so by implementing effective, and cost-efficient sampling protocols will help to optimise time and financial resources, particularly relevant to a disease such as schistosomiasis currently reliant on a single available drug. Here we explore the effect on measures of parasite genetic diversity of applying various field sampling approaches, both in terms of the number of (human) hosts sampled and the number of transmission stages (miracidia) sampled per host for a Schistosoma mansoni population in Tanzania pre- and post-treatment with PZQ. In addition, we explore population structuring within and between hosts by comparing the estimates of genetic diversity obtained assuming a 'component population' approach with those using an 'infrapopulation' approach. We found that increasing the number of hosts sampled, rather than the number of miracidia per host, gives more robust estimates of genetic diversity. We also found statistically significant population structuring (using Wright's F-statistics) and significant differences in the measures of genetic diversity depending on the parasite population definition. The relative advantages, disadvantages and, hence, subsequent reliability of these metrics for parasites with complex life-cycles are discussed, both for the specific epidemiological and ecological scenario under study here and for their future application to other areas and schistosome species.
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Dagan Y, Liljeroos K, Jokela J, Ben-Ami F. Clonal diversity driven by parasitism in a freshwater snail. J Evol Biol 2013; 26:2509-19. [PMID: 24118641 DOI: 10.1111/jeb.12245] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 07/12/2013] [Accepted: 08/12/2013] [Indexed: 11/28/2022]
Abstract
One explanation for the widespread abundance of sexual reproduction is the advantage that genetically diverse sexual lineages have under strong pressure from virulent coevolving parasites. Such parasites are believed to track common asexual host genotypes, resulting in negative frequency-dependent selection that counterbalances the population growth-rate advantage of asexuals in comparison with sexuals. In the face of genetically diverse asexual lineages, this advantage of sexual reproduction might be eroded, and instead sexual populations would be replaced by diverse assemblages of clonal lineages. We investigated whether parasite-mediated selection promotes clonal diversity in 22 natural populations of the freshwater snail Melanoides tuberculata. We found that infection prevalence explains the observed variation in the clonal diversity of M. tuberculata populations, whereas no such relationship was found between infection prevalence and male frequency. Clonal diversity and male frequency were independent of snail population density. Incorporating ecological factors such as presence/absence of fish, habitat geography and habitat type did not improve the predictive power of regression models. Approximately 11% of the clonal snail genotypes were shared among 2-4 populations, creating a web of 17 interconnected populations. Taken together, our study suggests that parasite-mediated selection coupled with host dispersal ecology promotes clonal diversity. This, in return, may erode the advantage of sexual reproduction in M. tuberculata populations.
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Affiliation(s)
- Y Dagan
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Thiele EA, Corrêa-Oliveira G, Gazzinelli A, Minchella DJ. Elucidating the temporal and spatial dynamics of Biomphalaria glabrata genetic diversity in three Brazilian villages. Trop Med Int Health 2013; 18:1164-73. [PMID: 23911082 DOI: 10.1111/tmi.12164] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The freshwater snail Biomphalaria glabrata is the principal intermediate host for the parasite Schistosoma mansoni within Brazil. We assessed the potential effects of snail population dynamics on parasite transmission dynamics via population genetics. METHODS We sampled snail populations located within the confines of three schistosome-endemic villages in the state of Minas Gerais, Brazil. Snails were collected from individual microhabitats following seasonal periods of flood and drought over the span of 1 year. Snail spatio-temporal genetic diversity and population differentiation of 598 snails from 12 sites were assessed at seven microsatellite loci. RESULTS Average genetic diversity was relatively low, ranging from 4.29 to 9.43 alleles per locus, and overall, subpopulations tended to exhibit heterozygote deficits. Genetic diversity was highly spatially partitioned among subpopulations, while virtually, no partitioning was observed across temporal sampling. Comparison with previously published parasite genetic diversity data indicated that S. mansoni populations are significantly more variable and less subdivided than those of the B. glabrata intermediate hosts. DISCUSSION Within individual Brazilian villages, observed distributions of snail genetic diversity indicate temporal stability and very restricted gene flow. This is contrary to observations of schistosome genetic diversity over the same spatial scale, corroborating the expectation that parasite gene flow at the level of individual villages is likely driven by vertebrate host movement.
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Affiliation(s)
- Elizabeth A Thiele
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
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Abstract
SUMMARYGene flow maintains the genetic integrity of species over large spatial scales, and dispersal maintains gene flow among separate populations. However, body size is a strong correlate of dispersal ability, with small-bodied organisms being poor dispersers. For parasites, small size may be compensated by using their hosts for indirect dispersal. In trematodes, some species use only aquatic hosts to complete their life cycle, whereas others use birds or mammals as final hosts, allowing dispersal among separate aquatic habitats. We performed the first test of the universality of the type of life cycle as a driver of parasite dispersal, using a meta-analysis of 16 studies of population genetic structure in 16 trematode species. After accounting for the geographic scale of a study, the number of populations sampled, and the genetic marker used, we found the type of life cycle to be the best predictor of genetic structure (Fst): trematode species bound to complete their life cycle within water showed significantly more pronounced genetic structuring than those leaving water through a bird or mammal host. This finding highlights the dependence of parasites on host traits for their dispersal, suggesting that genetic differentiation of parasites reflects the mobility of their hosts.
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Ndeda VM, Owiti DO, Aketch BO, Onyango DM. Genetic Relatedness of Diplostomum Species (Digenea: Diplostomidae) Infesting Nile Tilapia (Oreochromis Niloticus L.) in Western Kenya. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojapps.2013.38055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Konečný A, Estoup A, Duplantier JM, Bryja J, Bâ K, Galan M, Tatard C, Cosson JF. Invasion genetics of the introduced black rat (Rattus rattus) in Senegal, West Africa. Mol Ecol 2012. [PMID: 23206272 DOI: 10.1111/mec.12112] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An understanding of the evolutionary history and dynamics of invasive species is required for the construction of predictive models of future spread and the design of biological management measures. The black rat (Rattus rattus) is a major vertebrate invader with a worldwide distribution. Despite the severe ecological, economic and health impacts of this species, its evolutionary history has been little studied. We carried out extensive specimen sampling in Senegal, West Africa, and used microsatellite markers to describe the pattern and processes of invasion in this large continental area. The genetic data obtained were combined with historical knowledge concerning the presence of this species in Senegal. Data were analysed by a combination of Bayesian clustering and approximate Bayesian computation methods. The invasion pathways closely paralleled the history of human trade routes in Senegal. In several places, we detected the occurrence of multiple introductions from genetically different sources. Long-distance migration between towns and villages was also observed. Our findings suggest that genetic bottlenecks and admixture have played a major role in shaping the genetics of invasive black rats. These two processes may generate genetic novelty and favour rapid evolution along the invasion pathways.
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Affiliation(s)
- Adam Konečný
- INRA, CBGP, Campus international de Baillarguet, CS 30016, Montferrier-sur-Lez cedex, F-34988, France
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Savidge JA, Hopken MW, Witmer GW, Jojola SM, Pierce JJ, Burke PW, Piaggio AJ. Genetic evaluation of an attempted Rattus rattus eradication on Congo Cay, U.S. Virgin Islands, identifies importance of eradication units. Biol Invasions 2012. [DOI: 10.1007/s10530-012-0233-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Blasco-Costa I, Waters JM, Poulin R. Swimming against the current: genetic structure, host mobility and the drift paradox in trematode parasites. Mol Ecol 2011; 21:207-17. [PMID: 22118193 DOI: 10.1111/j.1365-294x.2011.05374.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Life-cycle characteristics and habitat processes can potentially interact to determine gene flow and genetic structuring of parasitic species. In this comparative study, we analysed the genetic structure of two freshwater trematode species with different life histories using cytochrome c oxidase I gene (COI) sequences and examined the effect of a unidirectional river current on their genetic diversity at 10 sites along the river. We found moderate genetic structure consistent with an isolation-by-distance pattern among subpopulations of Coitocaecum parvum but not in Stegodexamene anguillae. These contrasting parasite population structures were consistent with the relative dispersal abilities of their most mobile hosts (i.e. their definitive hosts). Genetic diversity decreased, as a likely consequence of unidirectional river flow, with increasing distance upstream in C. parvum, which utilizes a definitive host with only restricted mobility. The absence of such a pattern in S. anguillae suggests that unidirectional river flow affects parasite species differently depending on the dispersal abilities of their most mobile host. In conclusion, genetic structure, genetic diversity loss and drift are stronger in parasites whose most mobile hosts have low dispersal abilities and small home ranges. An additional prediction can be made for parasites under unidirectional drift: those parasites that stay longer in their benthic intermediate host or have more than one benthic intermediate hosts would have relatively high local recruitment and hence increased retention of upstream genetic diversity.
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Affiliation(s)
- I Blasco-Costa
- Department of Zoology, University of Otago, PO Box 56, Dunedin, New Zealand.
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