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Keeney DB, Cobb SA, Jadin RC, Orlofske SA. Atypical life cycle does not lead to inbreeding or selfing in parasites despite clonemate accumulation in intermediate hosts. Mol Ecol 2022; 32:1777-1790. [PMID: 36579456 DOI: 10.1111/mec.16837] [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: 09/21/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/30/2022]
Abstract
Many parasites utilize asexual and sexual reproduction and multiple hosts to complete their life cycles. How these taxa avoid inbreeding is an essential question for understanding parasite evolution and ecology. Aquatic trematodes that require multiple host species may benefit from diverse genetic parasite assemblages accumulating within second intermediate hosts prior to sexual reproduction in definitive hosts. However, Cotylurus species are able to utilize the same snail species as first and second intermediate hosts, potentially resulting in the accumulation of genetically identical clones (clonemates) prior to sexual reproduction. In this study, we developed and analysed novel microsatellite loci to determine if clones are accumulating within snail hosts prior to ingestion by bird hosts and the effects this could have on parasite inbreeding. Contrary to previous studies of aquatic trematodes, significantly large numbers of clonemates were present within snails, but full-sibs were not. Genetic structure was present over a relatively small geographical scale despite the use of vagile definitive hosts. Phylogenetic analysis identified the Cotylurus sp. clones as belonging to a single species. Despite the presence of clones within snails, mating between clones/selfing was not common and heterozygosity is maintained within individuals. Potential issues with clones mating may be mitigated by the presence of snails with numerous clones, the consumption of many snails by bird hosts and parasite clone recognition/avoidance. Use of the same host species for multiple life stages may have advantages when parasites are able to avoid inbreeding and the required hosts are common.
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Affiliation(s)
- Devon B Keeney
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, New York, USA
| | - Sarah A Cobb
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, New York, USA.,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Robert C Jadin
- Department of Biology, Northeastern Illinois University, Chicago, Illinois, USA.,Department of Biology, Museum of Natural History, University of Wisconsin - Stevens Point, Stevens Point, Wisconsin, USA
| | - Sarah A Orlofske
- Department of Biology, Northeastern Illinois University, Chicago, Illinois, USA.,Department of Biology, Museum of Natural History, University of Wisconsin - Stevens Point, Stevens Point, Wisconsin, USA
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Beesley NJ, Attree E, Vázquez-Prieto S, Vilas R, Paniagua E, Ubeira FM, Jensen O, Pruzzo C, Álvarez JD, Malandrini JB, Solana H, Hodgkinson JE. Evidence of population structuring following population genetic analyses of Fasciola hepatica from Argentina. Int J Parasitol 2021; 51:471-480. [PMID: 33581141 PMCID: PMC8113023 DOI: 10.1016/j.ijpara.2020.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 12/03/2022]
Abstract
320 Argentinian Fasciola hepatica were genotyped using a panel of microsatellites. Overall there was high genotypic richness: 263 distinct genotypes were identified. Population structuring of F. hepatica was evident across Argentina. Within these sub-populations there is largely random mating. Transmission of clonemates occurs: clonal parasites accounted for 26.6% of all parasites.
Fasciola hepatica, the liver fluke, is a trematode parasite that causes disease of economic importance in livestock. As a zoonosis this parasite also poses a risk to human health in areas where it is endemic. Population genetic studies can reveal the mechanisms responsible for genetic structuring (non-panmixia) within parasite populations and provide valuable insights into population dynamics, which in turn enables theoretical predictions of evolutionary dynamics such as the evolution of drug resistance. Here we genotyped 320 F. hepatica collected from 14 definitive hosts from four provinces in Argentina. STRUCTURE analysis indicated three population clusters, and principal coordinate analysis confirmed this, showing population clustering across provinces. Similarly, pairwise FST values amongst all four provinces were significant, with standardised pairwise FST (F′ST) ranging from 0.0754 to 0.6327. Therefore, population genetic structure was evident across these four provinces in Argentina. However, there was no evidence of deviation from Hardy–Weinberg equilibrium, so it appears that within these sub-populations there is largely random mating. We identified 263 unique genotypes, which gave a clonal diversity of 82%. Parasites with identical genotypes, clones, accounted for 26.6% of the parasites studied and were found in 12 of the 14 hosts studied, suggesting some clonemate transmission.
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Affiliation(s)
- Nicola J Beesley
- Veterinary Parasitology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK.
| | - Elizabeth Attree
- Veterinary Parasitology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Severo Vázquez-Prieto
- Universidad de Los Lagos, Osorno, Chile; Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile.
| | - Román Vilas
- Departamento de Zoología, Genética y Antropología Física, Facultad de Biología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Esperanza Paniagua
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Spain; Instituto de Investigación en Análisis Químicos y Biológicos (IAQBUS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Florencio M Ubeira
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Spain; Instituto de Investigación en Análisis Químicos y Biológicos (IAQBUS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Oscar Jensen
- Centro de Investigación en Zoonosis, Sarmiento, Chubut, Argentina
| | - Cesar Pruzzo
- Facultad de Ciencias Veterinarias, Universidad Nacional de la Plata (UNLP), La Plata, Argentina
| | - José D Álvarez
- Cátedra de Enfermedades Parasitarias, Facultad de Ciencias Veterinarias, Universidad Nacional del Nordeste (UNNE), Corrientes, Argentina
| | - Jorge Bruno Malandrini
- Laboratorio de Anatomía y Fisiología Animal, Facultad de Ciencias de la Salud, Universidad Nacional de Catamarca, San Fernando del Valle de Catamarca, Argentina
| | - Hugo Solana
- Laboratorio de Biología Celular y Molecular, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Jane E Hodgkinson
- Veterinary Parasitology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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Clonemate cotransmission supports a role for kin selection in a puppeteer parasite. Proc Natl Acad Sci U S A 2020; 117:5970-5976. [PMID: 32123093 DOI: 10.1073/pnas.1922272117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Host manipulation by parasites is a fascinating evolutionary outcome, but adaptive scenarios that often accompany even iconic examples in this popular field of study are speculative. Kin selection has been invoked as a means of explaining the evolution of an altruistic-based, host-manipulating behavior caused by larvae of the lancet fluke Dicrocoelium dendriticum in ants. Specifically, cotransmission of larval clonemates from a snail first host to an ant second host is presumed to lead to a puppeteer parasite in the ant's brain that has clonemates in the ant abdomen. Clonal relatedness between the actor (brain fluke) and recipients (abdomen flukes) enables kin selection of the parasite's host-manipulating trait, which facilitates transmission of the recipients to the final host. However, the hypothesis that asexual reproduction in the snail leads to a high abundance of clonemates in the same ant is untested. Clonal relationships between the manipulator in the brain and the nonmanipulators in the abdomen are also untested. We provide empirical data on the lancet fluke's clonal diversity within its ant host. In stark contrast to other trematodes, which do not exhibit the same host-manipulating behavioral trait, the lancet fluke has a high abundance of clonemates. Moreover, our data support existing theory that indicates that the altruistic behavior can evolve even in the presence of multiple clones within the same ant host. Importantly, our analyses conclusively show clonemate cotransmission into ants, and, as such, we find support for kin selection to drive the evolution and maintenance of this iconic host manipulation.
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Monks S, Violante-González J, Quiterio-Rendon G, García-Ibáñez S, Larumbe-Morán E, Rojas-Herrera AA. Life on the beach for a sand crab (Emerita rathbunae) (Decapoda, Hippidae): parasite-induced mortality of females in populations of the Pacific sand crab caused by Microphallus nicolli (Microphallidae). ZOOSYST EVOL 2016. [DOI: 10.3897/zse.92.8256] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Genetic differences among Haplorchis taichui populations in Indochina revealed by mitochondrial COX1 sequences. J Helminthol 2016; 91:597-604. [PMID: 27411962 DOI: 10.1017/s0022149x1600050x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Haplorchis taichui is an intestinal heterophyid fluke that is pathogenic to humans. It is widely distributed in Asia, with a particularly high prevalence in Indochina. Previous work revealed that the lack of gene flow between three distinct populations of Vietnamese H. taichui can be attributed to their geographic isolation with no interconnected river basins. To test the hypothesis that interconnected river basins allow gene flow between otherwise isolated populations of H. taichui, as previously demonstrated for another trematode, Opisthorchis viverrini, we compared the genetic structures of seven populations of H. taichui from various localities in the lower Mekong Basin, in Thailand and Laos, with those in Vietnam, using the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. To determine the gene flow between these H. taichui populations, we calculated their phylogenetic relationships, genetic distances and haplotype diversity. Each population showed very low nucleotide diversity at this locus. However, high levels of genetic differentiation between the populations indicated very little gene flow. A phylogenetic analysis divided the populations into four clusters that correlated with the country of origin. The negligible gene flow between the Thai and Laos populations, despite sharing the Mekong Basin, caused us to reject our hypothesis. Our data suggest that the distribution of H. taichui populations was incidentally associated with national borders.
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Blasco-Costa I, Cutmore SC, Miller TL, Nolan MJ. Molecular approaches to trematode systematics: ‘best practice’ and implications for future study. Syst Parasitol 2016; 93:295-306. [DOI: 10.1007/s11230-016-9631-2] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/09/2016] [Indexed: 11/29/2022]
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7
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Vazquez-Prieto S, Vilas R, Paniagua E, Ubeira FM. Influence of life history traits on the population genetic structure of parasitic helminths: a minireview. Folia Parasitol (Praha) 2015; 62. [DOI: 10.14411/fp.2015.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 09/22/2015] [Indexed: 11/19/2022]
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8
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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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9
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Cézilly F, Perrot-Minnot MJ, Rigaud T. Cooperation and conflict in host manipulation: interactions among macro-parasites and micro-organisms. Front Microbiol 2014; 5:248. [PMID: 24966851 PMCID: PMC4052506 DOI: 10.3389/fmicb.2014.00248] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/06/2014] [Indexed: 11/30/2022] Open
Abstract
Several parasite species are known to manipulate the phenotype of their hosts in ways that enhance their own transmission. Co-occurrence of manipulative parasites, belonging to the same species or to more than one species, in a single host has been regularly observed. Little is known, however, on interactions between co-occurring manipulative parasites with same or different transmission routes. Several models addressing this problem have provided predictions on how cooperation and conflict between parasites could emerge from multiple infections. Here, we review the empirical evidence in favor of the existence of synergistic or antagonistic interactions between co-occurring parasites, and highlight the neglected role of micro-organisms. We particularly discuss the actual importance of selective forces shaping the evolution of interactions between manipulative parasites in relation to parasite prevalence in natural populations, efficiency in manipulation, and type of transmission (i.e., horizontal versus vertical), and we emphasize the potential for future research.
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Affiliation(s)
- Frank Cézilly
- Equipe Ecologie Evolutive, UMR CNRS 6282 Biogéosciences, Université de BourgogneDijon, France
- Institut Universitaire de FranceStrasbourg, France
| | | | - Thierry Rigaud
- Equipe Ecologie Evolutive, UMR CNRS 6282 Biogéosciences, Université de BourgogneDijon, France
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Presswell B, Blasco-Costa I, Kostadinova A. Two new species of Maritrema Nicoll, 1907 (Digenea: Microphallidae) from New Zealand: morphological and molecular characterisation. Parasitol Res 2014; 113:1641-56. [DOI: 10.1007/s00436-014-3809-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 02/02/2014] [Indexed: 12/01/2022]
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11
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Brusentsov II, Katokhin AV, Brusentsova IV, Shekhovtsov SV, Borovikov SN, Goncharenko GG, Lider LA, Romashov BV, Rusinek OT, Shibitov SK, Suleymanov MM, Yevtushenko AV, Mordvinov VA. Low genetic diversity in wide-spread Eurasian liver fluke Opisthorchis felineus suggests special demographic history of this trematode species. PLoS One 2013; 8:e62453. [PMID: 23634228 PMCID: PMC3636034 DOI: 10.1371/journal.pone.0062453] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 03/21/2013] [Indexed: 01/09/2023] Open
Abstract
Opisthorchis felineus or Siberian liver fluke is a trematode parasite (Opisthorchiidae) that infects the hepato-biliary system of humans and other mammals. Despite its public health significance, this wide-spread Eurasian species is one of the most poorly studied human liver flukes and nothing is known about its population genetic structure and demographic history. In this paper, we attempt to fill this gap for the first time and to explore the genetic diversity in O. felineus populations from Eastern Europe (Ukraine, European part of Russia), Northern Asia (Siberia) and Central Asia (Northern Kazakhstan). Analysis of marker DNA fragments from O. felineus mitochondrial cytochrome c oxidase subunit 1 and 3 (cox1, cox3) and nuclear rDNA internal transcribed spacer 1 (ITS1) sequences revealed that genetic diversity is very low across the large geographic range of this species. Microevolutionary processes in populations of trematodes may well be influenced by their peculiar biology. Nevertheless, we suggest that lack of population genetics structure observed in O. felineus can be primarily explained by the Pleistocene glacial events and subsequent sudden population growth from a very limited group of founders. Rapid range expansion of O. felineus through Asian and European territories after severe bottleneck points to a high dispersal potential of this trematode species.
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Affiliation(s)
- Ilja I. Brusentsov
- Laboratory of Molecular Mechanisms of Pathological Processes, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexey V. Katokhin
- Laboratory of Molecular Mechanisms of Pathological Processes, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Irina V. Brusentsova
- Laboratory of Molecular Mechanisms of Pathological Processes, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Sergei V. Shekhovtsov
- Laboratory of Molecular Biotechnology, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Sergei N. Borovikov
- Department of Animal Biotechnology, S.Seifullin Kazakh Agrotechnical University, Astana, Republic of Kazakhstan
| | | | - Lyudmila A. Lider
- Department of Veterinary Medicine, S.Seifullin Kazakh Agrotechnical University, Astana, Republic of Kazakhstan
| | - Boris V. Romashov
- Scientific Department, Voronezh State Biosphere Reserve, Voronezh, Russia
| | - Olga T. Rusinek
- Department of Parasitology, The Baikal Museum at the Irkutsk Scientific Center, Siberian Branch, Russian Academy of Sciences, Listvyanka, Irkutsk, Russia
| | - Samat K. Shibitov
- Department of Epizootological Problems, All-Russian K.I. Skryabin Institute of Helminthology, Moscow, Russia
| | - Marat M. Suleymanov
- Laboratory of Molecular Mechanisms of Pathological Processes, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
| | - Andrey V. Yevtushenko
- Department of Parasitology Ichthyopathology and Arachnology, National Scientific Center “Institute of Experimental and Clinical Veterinary Medicine”, Kharkov, Ukraine
| | - Viatcheslav A. Mordvinov
- Laboratory of Molecular Mechanisms of Pathological Processes, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
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Testing local-scale panmixia provides insights into the cryptic ecology, evolution, and epidemiology of metazoan animal parasites. Parasitology 2012; 139:981-97. [PMID: 22475053 DOI: 10.1017/s0031182012000455] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
When every individual has an equal chance of mating with other individuals, the population is classified as panmictic. Amongst metazoan parasites of animals, local-scale panmixia can be disrupted due to not only non-random mating, but also non-random transmission among individual hosts of a single host population or non-random transmission among sympatric host species. Population genetics theory and analyses can be used to test the null hypothesis of panmixia and thus, allow one to draw inferences about parasite population dynamics that are difficult to observe directly. We provide an outline that addresses 3 tiered questions when testing parasite panmixia on local scales: is there greater than 1 parasite population/species, is there genetic subdivision amongst infrapopulations within a host population, and is there asexual reproduction or a non-random mating system? In this review, we highlight the evolutionary significance of non-panmixia on local scales and the genetic patterns that have been used to identify the different factors that may cause or explain deviations from panmixia on a local scale. We also discuss how tests of local-scale panmixia can provide a means to infer parasite population dynamics and epidemiology of medically relevant parasites.
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Koehler AV, Springer YP, Randhawa HS, Leung TLF, Keeney DB, Poulin R. Genetic and phenotypic influences on clone-level success and host specialization in a generalist parasite. J Evol Biol 2011; 25:66-79. [PMID: 22022929 DOI: 10.1111/j.1420-9101.2011.02402.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Studying resource specialization at the individual level can identify factors constraining the evolution of generalism. We quantified genotypic and phenotypic variability among infective stages of 20 clones of the parasitic trematode Maritrema novaezealandensis and measured their infection success and post-infection fitness (growth, egg output) in several crabs and amphipods. First, different clones varied in their infection success of different crustaceans. Second, neither genetic nor phenotypic traits had consistent effects on infection success across all host species. Although the results suggest a relationship between infection success and phenotypic variability, phenotypically variable clones were not better at infecting more host species than less variable ones. Third, genetic and phenotypic traits also showed no consistent correlations with post-infection fitness measures. Overall, we found no consistent clone-level specialization, with some clones acting as specialists and others, generalists. The trematode population therefore maintains an overall generalist strategy by comprising a mixture of clone-level specialists and generalists.
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Affiliation(s)
- Anson V Koehler
- Department of Zoology, University of Otago, Dunedin, New Zealand.
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14
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Criscione CD, Vilas R, Paniagua E, Blouin MS. More than meets the eye: detecting cryptic microgeographic population structure in a parasite with a complex life cycle. Mol Ecol 2011; 20:2510-24. [PMID: 21535278 DOI: 10.1111/j.1365-294x.2011.05113.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nonrandom recruitment of parasites among hosts can lead to genetic differentiation among hosts and mating dynamics that promote inbreeding. It has been hypothesized that strictly aquatic parasites with intermediate hosts will behave as panmictic populations among hosts because ample opportunity exists for random mixing of unrelated individuals during transmission to the definitive host. A previous allozyme study on the marine trematode Lecithochirium fusiforme did not support this hypothesis; in that, there was genetic differentiation among, and significant heterozygote deficiencies within, definitive hosts. We revisit this system and use microsatellites to obtain multilocus genotypes. Our goal was to determine whether cryptic subgroups and/or the presence of clones could account for the apparent deviation from 'panmixia'. We find strong evidence for cryptic subdivision (three genetic clusters) that causes the Wahlund effect and differentiation among definitive hosts. After accounting for these cryptic groups, we see panmictic genetic structure among definitive hosts that is consistent with the 'high mixing in aquatic habitats' hypothesis. We see evidence for cotransmission of clones in all three clusters, but this level of clonal structure did not have a major impact in causing deviations from Hardy-Weinberg equilibrium, and only affected genetic differentiation among hosts in one cluster. A cursory examination of the data may have led to incorrect conclusions about nonrandom transmission. However, it is obvious in this system that there is more than meets the eye in relation to the actual make-up of parasite populations. In general, the methods we employ will be useful for elucidating hidden patterns in other organisms where cryptic structure may be common (e.g. those with limited morphology or complex life histories).
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Affiliation(s)
- Charles D Criscione
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843, USA.
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15
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Dittmer J, Koehler AV, Richard FJ, Poulin R, Sicard M. Variation of parasite load and immune parameters in two species of New Zealand shore crabs. Parasitol Res 2011; 109:759-67. [PMID: 21400115 DOI: 10.1007/s00436-011-2319-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 02/23/2011] [Indexed: 11/28/2022]
Abstract
While parasites are likely to encounter several potential intermediate hosts in natural communities, a parasite's actual range of compatible hosts is limited by numerous biological factors ranging from behaviour to immunology. In crustaceans, two major components of immunity are haemocytes and the prophenoloxidase system involved in the melanisation of foreign particles. Here, we analysed metazoan parasite prevalence and loads in the two sympatric crab species Hemigrapsus crenulatus and Macrophthalmus hirtipes at two sites. In parallel, we analysed the variation in haemocyte concentration and amount of circulating phenoloxidase (PO) in the haemolymph of the same individuals in an attempt to (a) explain differences in parasite prevalence and loads in the two species at two sites and (b) assess the impact of parasites on these immune parameters. M. hirtipes harboured more parasites but also exhibited higher haemocyte concentrations than H. crenulatus independent of the study site. Thus, higher investment in haemocyte production for M. hirtipes does not seem to result in higher resistance to parasites. Analyses of variation in immune parameters for the two crab species between the two sites that differed in parasite prevalence showed common trends. (a) In general, haemocyte concentrations were higher at the site experiencing higher parasitic pressure while circulating PO activity was lower and (b) haemocyte concentrations were influenced by microphallid trematode metacercariae in individuals from the site with higher parasitic pressure. We suggest that the higher haemocyte concentrations observed in both crab species exposed to higher parasitic pressure may represent an adaptive response to the impact of parasites on this immune parameter.
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Affiliation(s)
- Jessica Dittmer
- Laboratoire Ecologie, Evolution, Symbiose, UMR CNRS 6556, Université de Poitiers, 40 avenue du Recteur Pineau, 86022 Poitiers, France.
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Spatial variation in parasite-induced mortality in an amphipod: shore height versus exposure history. Oecologia 2010; 163:651-9. [DOI: 10.1007/s00442-010-1593-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 02/15/2010] [Indexed: 10/19/2022]
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18
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Impact of temporal changes and host factors on the genetic structure of a population of Opisthorchis viverrini sensu lato in Khon Kaen Province (Thailand). Parasitology 2009; 136:1057-63. [DOI: 10.1017/s0031182009006441] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
SUMMARYThe population genetics of 317 individual Opisthorchis viverrini from Khon Kaen Province Thailand, from 4 different years and 4 cyprinid fish species was examined using multilocus enzyme electrophoresis of enolase (Enol), phosphoglucomutase (Pgm) and triose phosphate isomerase (Tpi). Allele and genotype frequencies for Enol and Pgm were consistent irrespective of year or host species. No heterozygote deficiency was detected for Enol. Significant heterozygote deficiencies were detected in 3 of 4 years for Pgm. For Tpi, allele frequencies of the most common allele and genotype frequency varied between years and among individuals from different host species. Heterozygote deficiencies for Tpi were detected in 2 years. No significant heterozygous deficiencies were detected among O. virerrini from different fish species in 2005, except at Pgm and Tpi from Puntioplites protozsron. There was no statistical significance in pairwise FST values between O. viverrini from Cyclocheilichthys armatus in different years or different host species in 2005. Significant departures from Hardy-Weinberg expectations and a high rate of gene flow in a population of O. viverrini are discussed in terms of self- and cross-fertilisation, natural selection, non-random mating, the Wahlund effect, presence of null alleles, intensity of infection, biology and ecology of their intermediate cyprinid hosts.
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Lagrue C, Poulin R, Keeney DB. EFFECTS OF CLONALITY IN MULTIPLE INFECTIONS ON THE LIFE-HISTORY STRATEGY OF THE TREMATODECOITOCAECUM PARVUMIN ITS AMPHIPOD INTERMEDIATE HOST. Evolution 2009; 63:1417-26. [DOI: 10.1111/j.1558-5646.2009.00619.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Steinauer ML, Hanelt B, Agola LE, Mkoji GM, Loker ES. Genetic structure of Schistosoma mansoni in western Kenya: The effects of geography and host sharing. Int J Parasitol 2009; 39:1353-62. [PMID: 19464296 DOI: 10.1016/j.ijpara.2009.04.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 04/29/2009] [Accepted: 04/30/2009] [Indexed: 10/20/2022]
Abstract
We examined the spatial structure of Schistosoma mansoni, a parasite of humans, from natural infections at two levels: across the Lake Victoria basin of Kenya and among snail hosts. Using 20 microsatellite markers we examined geographic patterns of relatedness and population structure of cercariae and found weak, but significant structure detected by some, but not all analyses. We hypothesise structure created by aggregations of clonal individuals or adherence of hosts to local transmission sites is eroded by high amounts of gene flow in the region. This finding also supports previous hypotheses concerning the evolution of drug resistance in the region. Intrasnail dynamics were investigated in the context of aggregation and kin selection theory to determine how relatedness and also sex influence host sharing and host exploitation. Cercarial production did not differ significantly between snails with one or two genotypes suggesting that mixed infections resulted in decreased individual fitness and provides a framework for reproductive competition. Coinfection patterns in snails were independent of parasite relatedness indicating that schistosomes were not aggregated according to their relatedness and that kin selection was not influencing host sharing. Additionally, host exploitation in coinfections (measured by cercarial production) was not negatively correlated with relatedness, as predicted by classical models due to increased competition and thus exploitation when parasites are unrelated. Because of the low levels of relatedness within the population, schistosomes may rarely encounter close relatives and kin selection mechanisms that influence the distribution of individuals within snails or the virulence mode of the parasites may simply have not evolved.
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Affiliation(s)
- M L Steinauer
- Department of Biological Sciences, University of New Mexico, MSC03 2020, Albuquerque, NM87131, USA.
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The influence of clonal diversity and intensity-dependence on trematode infections in an amphipod. Parasitology 2009; 136:339-48. [PMID: 19154642 DOI: 10.1017/s0031182008005416] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Individual animals are often infected not only by different parasite species, but also by multiple genotypes of the same parasite species. Genetic relatedness among parasites sharing a host is expected to modulate their strategies of resource exploitation, growth and virulence. We experimentally examined the effects that genetic diversity and infection intensity had on host mortality, infectivity and growth of the marine trematode Maritrema novaezealandensis in amphipod hosts. The presence of 2 versus 1 parasite genotype during infection did not influence subsequent host mortality, had different effects on infectivity among genotypes and did not influence growth or variation in parasite growth. Density-dependent growth reductions revealed that the number of parasites infecting a host was more important than their genetic relatedness. Temperature, host size, and host sex influenced the degree to which density-dependent factors affected parasite growth. Our results suggest that the effects of parasite relatedness vary among parasite genotypes in this trematode species, and reveal that many factors play an important role during parasite development and transmission.
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Keeney DB, Lagrue C, Bryan-Walker K, Khan N, Leung TL, Poulin R. The use of fluorescent fatty acid analogs as labels in trematode experimental infections. Exp Parasitol 2008; 120:15-20. [DOI: 10.1016/j.exppara.2008.04.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 03/30/2008] [Accepted: 04/03/2008] [Indexed: 10/22/2022]
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Leung TLF, Poulin R, Keeney DB. Accumulation of diverse parasite genotypes within the bivalve second intermediate host of the digenean Gymnophallus sp. Int J Parasitol 2008; 39:327-31. [PMID: 18725226 DOI: 10.1016/j.ijpara.2008.07.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 07/24/2008] [Accepted: 07/25/2008] [Indexed: 10/21/2022]
Abstract
The complex life cycle of digenean trematodes with alternating stages of asexual multiplication and sexual reproduction can generate interesting within-host population genetic patterns. Metacercarial stages found in the second intermediate host are generally accumulated from the environment. Highly mobile second intermediate hosts can sample a broad range of cercarial genotypes and accumulate genetically diverse packets of metacercariae, but it is unclear whether the same would occur in systems where the second intermediate host is relatively immobile and cercarial dispersal is the sole mechanism that can maintain genetic homogeneity at the population level. Here, using polymorphic microsatellite markers, we addressed this issue by genotyping metacercariae of the trematode Gymnophallus sp. from the New Zealand cockle Austrovenus stutchburyi. Despite the relatively sessile nature of the second intermediate host of Gymnophallus, very high genotypic diversity of metacercariae was found within cockles, with only two cockles harbouring multiple copies of a single clonal lineage. There was no evidence of population structuring at the scale of our study, suggesting the existence of a well-mixed population. Our results indicate that (i) even relatively sessile second intermediate hosts can accumulate a high diversity of genotypes and (ii) the dispersal ability of cercariae, whether passive or not, is much greater than expected for such small and short-lived organisms. The results also support the role of the second intermediate host as an accumulator of genetic diversity in the trematode life cycle.
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Affiliation(s)
- Tommy L F Leung
- Department of Zoology, University of Otago, Otago, New Zealand.
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