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Cortazar-Chinarro M, Richter-Boix A, Rödin-Mörch P, Halvarsson P, Logue JB, Laurila A, Höglund J. Association between the skin microbiome and MHC class II diversity in an amphibian. Mol Ecol 2024; 33:e17198. [PMID: 37933583 DOI: 10.1111/mec.17198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 10/20/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023]
Abstract
Microbiomes play an important role in determining the ecology and behaviour of their hosts. However, questions remain pertaining to how host genetics shape microbiomes, and how microbiome composition influences host fitness. We explored the effects of geography, evolutionary history and host genetics on the skin microbiome diversity and structure in a widespread amphibian. More specifically, we examined the association between bacterial diversity and composition and the major histocompatibility complex class II exon 2 diversity in 12 moor frog (Rana arvalis) populations belonging to two geographical clusters that show signatures of past and ongoing differential selection. We found that while bacterial alpha diversity did not differ between the two clusters, MHC alleles/supertypes and genetic diversity varied considerably depending on geography and evolutionary history. Bacterial alpha diversity was positively correlated with expected MHC heterozygosity and negatively with MHC nucleotide diversity. Furthermore, bacterial community composition showed significant variation between the two geographical clusters and between specific MHC alleles/supertypes. Our findings emphasize the importance of historical demographic events on hologenomic variation and provide new insights into how immunogenetic host variability and microbial diversity may jointly influence host fitness with consequences for disease susceptibility and population persistence.
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Affiliation(s)
- M Cortazar-Chinarro
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
- MEMEG/Department of Biology, Lund University, Lund, Sweden
- Department of Earth Ocean and Atmospheric Sciences, Faculty of Science 2020-2207, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Richter-Boix
- Department of Political and Social Science, Pompeu Fabra University, Barcelona, Spain
| | - P Rödin-Mörch
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - P Halvarsson
- Parasitology/Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - J B Logue
- Aquatic Ecology/Department of Biology, Lund University, Lund, Sweden
- SLU University Library, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - A Laurila
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - J Höglund
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
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Haikukutu L, Lyaku JR, Lyimo CM, Eiseb SJ, Makundi RH, Olayemi A, Wilhelm K, Müller-Klein N, Schmid DW, Fleischer R, Sommer S. Immunogenetics, sylvatic plague and its vectors: insights from the pathogen reservoir Mastomys natalensis in Tanzania. Immunogenetics 2023; 75:517-530. [PMID: 37853246 PMCID: PMC10651713 DOI: 10.1007/s00251-023-01323-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 10/08/2023] [Indexed: 10/20/2023]
Abstract
Yersinia pestis is a historically important vector-borne pathogen causing plague in humans and other mammals. Contemporary zoonotic infections with Y. pestis still occur in sub-Saharan Africa, including Tanzania and Madagascar, but receive relatively little attention. Thus, the role of wildlife reservoirs in maintaining sylvatic plague and spillover risks to humans is largely unknown. The multimammate rodent Mastomys natalensis is the most abundant and widespread rodent in peri-domestic areas in Tanzania, where it plays a major role as a Y. pestis reservoir in endemic foci. Yet, how M. natalensis' immunogenetics contributes to the maintenance of plague has not been investigated to date. Here, we surveyed wild M. natalensis for Y. pestis vectors, i.e., fleas, and tested for the presence of antibodies against Y. pestis using enzyme-linked immunosorbent assays (ELISA) in areas known to be endemic or without previous records of Y. pestis in Tanzania. We characterized the allelic and functional (i.e., supertype) diversity of the major histocompatibility complex (MHC class II) of M. natalensis and investigated links to Y. pestis vectors and infections. We detected antibodies against Y. pestis in rodents inhabiting both endemic areas and areas considered non-endemic. Of the 111 nucleotide MHC alleles, only DRB*016 was associated with an increased infestation with the flea Xenopsylla. Surprisingly, we found no link between MHC alleles or supertypes and antibodies of Y. pestis. Our findings hint, however, at local adaptations towards Y. pestis vectors, an observation that more exhaustive sampling could unwind in the future.
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Affiliation(s)
- Lavinia Haikukutu
- Department of Wildlife Management, Sokoine University of Agriculture, Morogoro, Tanzania.
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.
- Africa Centre of Excellence for Innovative Rodent Pest Management and Biosensor Technology Development, Sokoine University of Agriculture, Morogoro, Tanzania.
| | - Japhet R Lyaku
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Namibia, Windhoek, Namibia
| | - Charles M Lyimo
- Department of Animal, Aquaculture and Range Sciences, Sokoine University of Agriculture, Chuo Kikuu, Morogoro, Tanzania
| | - Seth J Eiseb
- Department of Environmental Sciences, University of Namibia, Windhoek, Namibia
| | - Rhodes H Makundi
- Africa Centre of Excellence for Innovative Rodent Pest Management and Biosensor Technology Development, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Ayodeji Olayemi
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
- Natural History Museum, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | - Kerstin Wilhelm
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Nadine Müller-Klein
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Dominik W Schmid
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Ramona Fleischer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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Napolitano C, Sacristán I, Acuña F, Aguilar E, García S, López-Jara MJ, Cabello J, Hidalgo-Hermoso E, Poulin E, Grueber CE. Assessing micro-macroparasite selective pressures and anthropogenic disturbance as drivers of immune gene diversity in a Neotropical wild cat. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 897:166289. [PMID: 37591403 DOI: 10.1016/j.scitotenv.2023.166289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 08/11/2023] [Accepted: 08/12/2023] [Indexed: 08/19/2023]
Abstract
Anthropogenic environmental change is reducing available habitat for wild species, providing novel selection pressures such as infectious diseases and causing species to interact in new ways. The potential for emerging infectious diseases and zoonoses at the interface between humans, domestic animals, and wild species is a key global concern. In vertebrates, diversity at the major histocompatibility complex MHC is critical to disease resilience, and its study in wild populations provides insights into eco-evolutionary dynamics that human activities alter. In natural populations, variation at MHC loci is partly maintained by balancing selection, driven by pathogenic selective pressures. We hypothesize that MHC genetic diversity differs between guigna populations inhabiting human-dominated landscapes (higher pathogen pressures) versus more natural habitats (lower pathogen pressures). We predict that MHC diversity in guignas would be highest in human-dominated landscapes compared with continuous forest habitats. We also expected to find higher MHC diversity in guignas infected with micro and macro parasites (higher parasite load) versus non infected guignas. We characterized for the first time the genetic diversity at three MHC class I and II exons in 128 wild guignas (Leopardus guigna) across their distribution range in Chile (32-46° S) and Argentina, representing landscapes with varying levels of human disturbance. We integrated MHC sequence diversity with multiple measures of anthropogenic disturbance and both micro and macro parasite infection data. We also assessed signatures of positive selection acting on MHC genes. We found significantly higher MHC class I diversity in guignas inhabiting landscapes where houses were present, and with lower percentage of vegetation cover, and also in animals with more severe cardiorespiratory helminth infection (richness and intensity) and micro-macroparasite co-infection. This comprehensive, landscape-level assessment further enhances our knowledge on the evolutionary dynamics and adaptive potential of vertebrates in the face of emerging infectious disease threats and increasing anthropogenic impacts.
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Affiliation(s)
- Constanza Napolitano
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Osorno, Chile; Institute of Ecology and Biodiversity (IEB), Concepción, Chile; Cape Horn International Center (CHIC), Puerto Williams, Chile.
| | - Irene Sacristán
- Universidad Andres Bello, Santiago, Chile; Animal Health Research Centre, National Institute for Agricultural and Food Research and Technology (INIA), Centro Superior de Investigaciones Científicas (CSIC), Valdeolmos, Madrid, Spain
| | - Francisca Acuña
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Emilio Aguilar
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Sebastián García
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - María José López-Jara
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Javier Cabello
- Chiloé Silvestre Center for the Conservation of Biodiversity, Ancud, Chile
| | | | - Elie Poulin
- Institute of Ecology and Biodiversity (IEB), Concepción, Chile; Millennium Institute of Biodiversity of Antarctic and Subantarctic Ecosystems and Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Catherine E Grueber
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, Australia
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Influence of habitat alteration on the structure of helminth communities in small mammals: a systematic review and critical appraisal of theory and current evidence. Parasitol Res 2023; 122:1053-1070. [PMID: 36894783 DOI: 10.1007/s00436-023-07804-8] [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: 12/25/2022] [Accepted: 02/24/2023] [Indexed: 03/11/2023]
Abstract
Despite the extensive information on the effects of habitat alteration on the structure of helminth communities in small mammals, the evidence is still inconclusive. A systematic review was carried out using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guideline to compile and synthesize available literature on the influence of habitat alteration on the structure of helminth communities in small mammals. The aim of this review was to describe the variation in infection rates of helminth species associated with habitat alteration and to discuss the theoretical framework that may explain such changes in relation to parasite, host, and environmental features. Twenty-three scientific articles published between 2005 and 2022 were reviewed, 22 of which investigated parasite prevalence, 10 parasite burden, and 14 parasite richness in both altered and natural habitats. Information in assessed articles suggests that the structure of helminth communities in small mammals can be impacted by anthropogenic habitat alteration in various ways. Infection rates of monoxenous and heteroxenous helminths may increase or decrease in small mammals depending on whether their hosts (definitive and intermediate) are available, and environmental and host conditions modify the survival and transmission of parasitic forms. Also, given that habitat alteration may favor inter-species contacts, transmission rates of low host-specific helminths could be increased due to exposure to new reservoir hosts. In a continually changing world, it is essential to assess the spatio-temporal variations of helminth communities in wildlife inhabiting altered and natural habitats to determine potential impacts on wildlife conservation and public health.
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Carrera-Játiva PD, Torres C, Figueroa-Sandoval F, Beltrami E, Verdugo C, Landaeta-Aqueveque C, Acosta-Jamett G. Gastrointestinal parasites in wild rodents in Chiloé Island-Chile. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA = BRAZILIAN JOURNAL OF VETERINARY PARASITOLOGY : ORGAO OFICIAL DO COLEGIO BRASILEIRO DE PARASITOLOGIA VETERINARIA 2023; 32:e017022. [PMID: 36629665 DOI: 10.1590/s1984-29612023002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 11/30/2022] [Indexed: 01/11/2023]
Abstract
Gastrointestinal parasites are well-documented in small mammals from north-central Chile, but little is known about endoparasites of rodents in southern Chile. A survey was conducted between January and February 2018 to evaluate gastrointestinal parasites and risk factors of wild rodents that live in rural areas in Northern Chiloé Island, Chile. A total of 174 fecal samples from rodents of six native and one introduced species were collected and examined using the Mini-FLOTAC method. Also, 41 individuals of four native wild rodent species were examined furtherly to determinate adult parasites from gastrointestinal tracts. The overall prevalence of endoparasites was 89.65% (156). Helminth egg types included: Rodentolepis spp., Capillariidae, Trichuris sp., Syphacia sp., oxyurid-type eggs, Strongyloides sp., Spirurid-type eggs, Strongilid-type eggs, Moniliformis sp., and an unidentified nematode egg and larvae. Protozoa comprised coccidia, amoeba, and unidentified cysts. From necropsies, adult parasites involved Syphacia sp. Trichuris sp., Protospirura sp. and Physaloptera sp. In Abrothrix olivacea, individuals with low-body-mass index exhibited reduced infection probability for Spirurid-type and Strongilid-type eggs. Some parasites in this study may affect human health. In rural settings where environmental conditions are changing, more research should be undertaken to understand parasitic infections in wildlife and implications for public health and conservation.
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Affiliation(s)
- Patricio David Carrera-Játiva
- Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Constanza Torres
- Escuela de Tecnología Médica, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Fernanda Figueroa-Sandoval
- Departamento de Patología y Medicina Preventiva, Facultad de Ciencias Veterinarias, Universidad de Concepción, Chillán, Chile
| | - Esperanza Beltrami
- Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Claudio Verdugo
- Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Center for Evolution and Disease Surveillance, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Carlos Landaeta-Aqueveque
- Departamento de Patología y Medicina Preventiva, Facultad de Ciencias Veterinarias, Universidad de Concepción, Chillán, Chile
| | - Gerardo Acosta-Jamett
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Center for Evolution and Disease Surveillance, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
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Surviving despite reduce MHC variation: selection patterns and genetic variation of the endangered Huillín (Lontra provocax). MAMMAL RES 2021. [DOI: 10.1007/s13364-021-00594-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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7
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Old JM, Hermsen EM, Young LJ. MHC Class II variability in bare-nosed wombats (Vombatus ursinus). AUSTRALIAN MAMMALOGY 2020. [DOI: 10.1071/am19015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Studies of gene diversity are used to investigate population dynamics, including immunological fitness. Aside from the selection of an appropriate gene target, an important factor that underpins these studies is the ability to recover viable DNA samples from native animals that are protected, threatened or difficult to sample or locate such as the bare-nosed wombat (Vombatus ursinus). In this study, we used genomic DNA extracted from muscle tissue samples and also identified the optimal method to extract DNA from fresh wombat scat samples to enable further analyses to be performed using non-invasive techniques. The DNA was probed via the polymerase chain reaction using previously targeted marsupial Major Histocompatibility Complex (MHC) gene primers. These genes are highly variable and associated with binding and presentation of pathogens in the immune system. Twenty-three unique MHC Class II DAB V. ursinus gene sequences were translated to 21 unique predicted peptide sequences from 34 individual tissue or scat samples. Vombatus ursinus MHC Class II DAB gene and peptide sequences were most similar to other marsupial DNA and peptide sequences. Further analysis also indicated the likelihood of MHC Class II DAB family membership through motif identification. Additional sampling is required to assess the full level of diversity of MHC Class II DAB genes among V. ursinus populations; however, this study is the first to identify MHC genes in a wombat and will advance immunological and disease studies of the species.
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Carim K, Vindenes Y, Eby L, Barfoot C, Vøllestad L. Life history, population viability, and the potential for local adaptation in isolated trout populations. Glob Ecol Conserv 2017. [DOI: 10.1016/j.gecco.2017.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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9
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Reproductive effort and seasonality associated with male-biased parasitism in Gracilinanus agilis (Didelphimorphia: Didelphidae) infected by Eimeria spp. (Apicomplexa: Eimeriidae) in the Brazilian cerrado. Parasitology 2015; 142:1086-94. [PMID: 25877479 DOI: 10.1017/s0031182015000402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The aggregation of parasites among hosts is associated with differential host exposure and susceptibility to parasites, which varies according to host gender, body size, reproductive status and environmental factors. We evaluated the role of these factors on infestation by Eimeria spp. (Eimeriidae) in the agile gracile mouse opossum (Gracilinanus agilis), a semelparous didelphid inhabiting neotropical savannahs. Eimeria spp. abundance and prevalence among G. agilis were associated with the breeding status of individuals and to a lesser extent to climatic season, with both sexes presenting higher Eimeria spp. burdens during late breeding/wet season. On the other hand, male-biased parasitism was restricted to dry/mating season. We suggest that male spatial organization and diet may account for increased parasite burdens within this sex, although future studies should evaluate the role of physiological differences associated with androgen hormones. Finally, a rapid increase in Eimeria spp. loads among females during the late breeding/wet season seems associated with seasonal changes in susceptibility, due to breeding costs related to semelparity, and exposure to infective propagules, while male-die off seems to explain maintenance of higher Eimeria spp. burdens within this sex in the same period.
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10
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454 screening of individual MHC variation in an endemic island passerine. Immunogenetics 2014; 67:149-62. [PMID: 25515684 PMCID: PMC4325181 DOI: 10.1007/s00251-014-0822-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 11/28/2014] [Indexed: 11/03/2022]
Abstract
Genes of the major histocompatibility complex (MHC) code for receptors that are central to the adaptive immune response of vertebrates. These genes are therefore important genetic markers with which to study adaptive genetic variation in the wild. Next-generation sequencing (NGS) has increasingly been used in the last decade to genotype the MHC. However, NGS methods are highly prone to sequencing errors, and although several methodologies have been proposed to deal with this, until recently there have been no standard guidelines for the validation of putative MHC alleles. In this study, we used the 454 NGS platform to screen MHC class I exon 3 variation in a population of the island endemic Berthelot's pipit (Anthus berthelotii). We were able to characterise MHC genotypes across 309 individuals with high levels of repeatability. We were also able to determine alleles that had low amplification efficiencies, whose identification within individuals may thus be less reliable. At the population level we found lower levels of MHC diversity in Berthelot's pipit than in its widespread continental sister species the tawny pipit (Anthus campestris), and observed trans-species polymorphism. Using the sequence data, we identified signatures of gene conversion and evidence of maintenance of functionally divergent alleles in Berthelot's pipit. We also detected positive selection at 10 codons. The present study therefore shows that we have an efficient method for screening individual MHC variation across large datasets in Berthelot's pipit, and provides data that can be used in future studies investigating spatio-temporal patterns and scales of selection on the MHC.
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11
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Lau Q, Jaratlerdsiri W, Griffith JE, Gongora J, Higgins DP. MHC class II diversity of koala (Phascolarctos cinereus) populations across their range. Heredity (Edinb) 2014; 113:287-96. [PMID: 24690756 PMCID: PMC4181066 DOI: 10.1038/hdy.2014.30] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/04/2013] [Accepted: 02/10/2014] [Indexed: 11/08/2022] Open
Abstract
Major histocompatibility complex class II (MHCII) genes code for proteins that bind and present antigenic peptides and trigger the adaptive immune response. We present a broad geographical study of MHCII DA β1 (DAB) and DB β1 (DBB) variants of the koala (Phascolarctos cinereus; n=191) from 12 populations across eastern Australia, with a total of 13 DAB and 7 DBB variants found. We identified greater MHCII variation and, possibly, additional gene copies in koala populations in the north (Queensland and New South Wales) relative to the south (Victoria), confirmed by STRUCTURE analyses and genetic differentiation using analysis of molecular variance. The higher MHCII diversity in the north relative to south could potentially be attributed to (i) significant founder effect in Victorian populations linked to historical translocation of bottlenecked koala populations and (ii) increased pathogen-driven balancing selection and/or local genetic drift in the north. Low MHCII genetic diversity in koalas from the south could reduce their potential response to disease, although the three DAB variants found in the south had substantial sequence divergence between variants. This study assessing MHCII diversity in the koala with historical translocations in some populations contributes to understanding the effects of population translocations on functional genetic diversity.
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Affiliation(s)
- Q Lau
- Faculty of Veterinary Science, University of Sydney, Camperdown, New South Wales, Australia
| | - W Jaratlerdsiri
- Faculty of Veterinary Science, University of Sydney, Camperdown, New South Wales, Australia
| | - J E Griffith
- Faculty of Veterinary Science, University of Sydney, Camperdown, New South Wales, Australia
| | - J Gongora
- Faculty of Veterinary Science, University of Sydney, Camperdown, New South Wales, Australia
| | - D P Higgins
- Faculty of Veterinary Science, University of Sydney, Camperdown, New South Wales, Australia
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12
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Froeschke G, Matthee S. Landscape characteristics influence helminth infestations in a peri-domestic rodent--implications for possible zoonotic disease. Parasit Vectors 2014; 7:393. [PMID: 25159989 PMCID: PMC4158073 DOI: 10.1186/1756-3305-7-393] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 08/18/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Anthropogenic habitat change often results in altered landscapes that can provide new environments where hosts, parasites and pathogens can interact. The latter can have implications for human and animal health when in close proximity to developed areas. We recorded the helminth species richness and level of infestation in the peri-domestic rodent, Rhabdomys pumilio, in three different human linked landscapes. The aim was, to investigate the potential of R. pumilio to act as a reservoir host for zoonotic helminths and to compare the effect of anthropogenic habitat change on its parasite infestation patterns. METHODS Rodents (n = 518) were trapped in natural areas (nature reserves) and in three human linked landscapes (crop, livestock and urban fragments). Gastrointestinal parasite burdens were recovered and helminths identified from each animal. Generalized linear models were applied to investigate the effect of different landscape types on helminth infestation. RESULTS Rhabdomys pumilio was the most abundant rodent species within each landscape type. Eight helminths species were recovered and overall helminth prevalence was 86.68%. Mean helminth species richness, prevalence and abundance were significantly higher in crop fragments compared to natural landscapes and overall lower for nematodes in livestock and urban areas. Cestode prevalence showed a tendency to be elevated at anthropogenic linked landscape types. CONCLUSIONS Host parameters and parasite infestations were strongly influenced by landscape characteristics. Resource-rich landscapes (crop fragments) provide favorable conditions for helminth infestations, while landscapes that are more closely associated with humans (livestock and urban landscapes) pose a larger risk by zoonotic species.
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Affiliation(s)
- Götz Froeschke
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Sonja Matthee
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
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13
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Cutrera AP, Zenuto RR, Lacey EA. Interpopulation differences in parasite load and variable selective pressures on MHC genes inCtenomys talarum. J Mammal 2014. [DOI: 10.1644/13-mamm-a-120] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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14
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Zhang M, He H. Parasite-mediated selection of major histocompatibility complex variability in wild brandt's voles (Lasiopodomys brandtii) from Inner Mongolia, China. BMC Evol Biol 2013; 13:149. [PMID: 23848494 PMCID: PMC3720540 DOI: 10.1186/1471-2148-13-149] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/27/2013] [Indexed: 11/21/2022] Open
Abstract
Background Genes of the major histocompatibility complex (MHC) exhibit high levels of variability, which is believed to have arisen through pathogen-mediated selection. We investigated the relationship between parasite load and genetic diversity at selectively neutral, non-coding markers (microsatellites) and adaptive genetic variation at a functionally important part of the MHC in six independent natural populations of Brandt’s voles (Lasiopodomys brandtii) from two regions of the Xilingol Grassland area of Inner Mongolia. Results Two-hundred and fifty-two voles were screened for gastrointestinal parasites, and were assessed for genetic variation. Parasite screening was done through non-invasive fecal egg counts, while allelic diversity was determined via single-stranded conformation polymorphism and DNA sequencing. We detected eight distinct helminth egg morphotypes. A total of 10 microsatellite loci were genotyped and 19 unique MHC class II B alleles were isolated. The rate of nonsynonymous substitutions (dN) exceeded the rate of synonymous substitutions (dS) at putative antigen binding sites of DRB. Neutral and adaptive genetic diversity differed between the six vole populations. To test the main pathogen-driven selection hypotheses for the maintenance of host MHC diversity and parasite species-specific co-evolutionary effects, multivariate approaches (generalized linear mixed models) were used to test for associations between the MHC class II DRB genotype and infections with nematodes. We found no evidence for heterozygote advantage, and overall heterozygosity was lower than expected in the MHC alleles. We identified an association between the parasite load and specific MHC alleles in the voles, and this pattern varied between geographic regions. Conclusions The results suggest that MHC variability in Brandt’s voles is maintained by rare allele advantage and fluctuating selection, but the data failed to show any heterozygote advantage effect. Our results add to a growing body of evidence showing that the mode and relative strength of pathogen-driven selection acting on MHC diversity varies within specific wild populations. In addition, our study contributes to the understanding of what maintains MHC diversity, of host-pathogen coevolution and of how genetic diversity is maintained in voles.
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Affiliation(s)
- Min Zhang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Byles B, Catzeflis F, Scheibel RP, Jiménez FA. Gastrointestinal Helminths of Two Species of Mouse Opossums (Marmosa demeraraeandMarmosa murina) from French Guiana. COMP PARASITOL 2013. [DOI: 10.1654/4621.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Characterisation of four major histocompatibility complex class II genes of the koala (Phascolarctos cinereus). Immunogenetics 2012; 65:37-46. [PMID: 23089959 DOI: 10.1007/s00251-012-0658-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 10/08/2012] [Indexed: 12/12/2022]
Abstract
Major histocompatibility complex (MHC) class II molecules have an integral role in the adaptive immune response, as they bind and present antigenic peptides to T helper lymphocytes. In this study of koalas, species-specific primers were designed to amplify exon 2 of the MHC class II DA and DB genes, which contain much of the peptide-binding regions of the α and β chains. A total of two DA α1 domain variants and eight DA β1 (DAB), three DB α1 and five DB β1 variants were amplified from 20 koalas from two free-living populations from South East Queensland and the Port Macquarie region in northern New South Wales. We detected greater variation in the β1 than in the α1 domains as well as evidence of positive selection in DAB. The present study provides a springboard to future investigation of the role of MHC in disease susceptibility in koalas.
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Froeschke G, Sommer S. Insights into the complex associations between MHC class II DRB polymorphism and multiple gastrointestinal parasite infestations in the striped mouse. PLoS One 2012; 7:e31820. [PMID: 22389675 PMCID: PMC3289624 DOI: 10.1371/journal.pone.0031820] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 01/13/2012] [Indexed: 11/19/2022] Open
Abstract
Differences in host susceptibility to different parasite types are largely based on the degree of matching between immune genes and parasite antigens. Specifically the variable genes of the major histocompatibility complex (MHC) play a major role in the defence of parasites. However, underlying genetic mechanisms in wild populations are still not well understood because there is a lack of studies which deal with multiple parasite infections and their competition within. To gain insights into these complex associations, we implemented the full record of gastrointestinal nematodes from 439 genotyped individuals of the striped mouse, Rhabdomys pumilio. We used two different multivariate approaches to test for associations between MHC class II DRB genotype and multiple nematodes with regard to the main pathogen-driven selection hypotheses maintaining MHC diversity and parasite species-specific co-evolutionary effects. The former includes investigations of a 'heterozygote advantage', or its specific form a 'divergent-allele advantage' caused by highly dissimilar alleles as well as possible effects of specific MHC-alleles selected by a 'rare allele advantage' (= negative 'frequency-dependent selection'). A combination of generalized linear mixed models (GLMMs) and co-inertia (COIA) analyses made it possible to consider multiple parasite species despite the risk of type I errors on the population and on the individual level. We could not find any evidence for a 'heterozygote' advantage but support for 'divergent-allele' advantage and infection intensity. In addition, both approaches demonstrated high concordance of positive as well as negative associations between specific MHC alleles and certain parasite species. Furthermore, certain MHC alleles were associated with more than one parasite species, suggesting a many-to-many gene-parasite co-evolution. The most frequent allele Rhpu-DRB*38 revealed a pleiotropic effect, involving three nematode species. Our study demonstrates the co-existence of specialist and generalist MHC alleles in terms of parasite detection which may be an important feature in the maintenance of MHC polymorphism.
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Affiliation(s)
| | - Simone Sommer
- Evolutionary Genetics, Leibniz-Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
- * E-mail:
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Jobbins SE, Sanderson CE, Griffith JE, Krockenberger MB, Belov K, Higgins DP. Diversity of MHC class II DAB1 in the koala (Phascolarctos cinereus). AUST J ZOOL 2012. [DOI: 10.1071/zo12013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The host immune response is an important factor determining the outcome of the host–pathogen–environment interaction. At the gateway between the innate and adaptive immune systems are MHC molecules, which facilitate antigen presentation to T lymphocytes, and initiate the adaptive immune response. Despite their integral role in adaptive immunity, the genes encoding class II MHC molecules have not been examined directly in koalas. Furthermore, indirect historical evidence suggests that this species might lack functional diversity in class II MHC genes, with potential implications for disease susceptibility. We have examined diversity in the β chain genes of the koala class II MHC DA gene family and identified 23 alleles, including several atypical alleles. The levels of diversity observed are consistent with other marsupial and eutherian species, and do not support the paucity of variation suggested by the early literature. These findings are relevant to the conservation management of koalas and provide both a benchmark for maintaining population diversity and a platform for further conservation genetic research in this species.
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Püttker T, Bueno AA, Dos Santos de Barros C, Sommer S, Pardini R. Immigration rates in fragmented landscapes--empirical evidence for the importance of habitat amount for species persistence. PLoS One 2011; 6:e27963. [PMID: 22125643 PMCID: PMC3220714 DOI: 10.1371/journal.pone.0027963] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 10/28/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The total amount of native vegetation is an important property of fragmented landscapes and is known to exert a strong influence on population and metapopulation dynamics. As the relationship between habitat loss and local patch and gap characteristics is strongly non-linear, theoretical models predict that immigration rates should decrease dramatically at low levels of remaining native vegetation cover, leading to patch-area effects and the existence of species extinction thresholds across fragmented landscapes with different proportions of remaining native vegetation. Although empirical patterns of species distribution and richness give support to these models, direct measurements of immigration rates across fragmented landscapes are still lacking. METHODOLOGY/PRINCIPAL FINDINGS Using the Brazilian Atlantic forest marsupial Gray Slender Mouse Opossum (Marmosops incanus) as a model species and estimating demographic parameters of populations in patches situated in three landscapes differing in the total amount of remaining forest, we tested the hypotheses that patch-area effects on population density are apparent only at intermediate levels of forest cover, and that immigration rates into forest patches are defined primarily by landscape context surrounding patches. As expected, we observed a positive patch-area effect on M. incanus density only within the landscape with intermediate forest cover. Density was independent of patch size in the most forested landscape and the species was absent from the most deforested landscape. Specifically, the mean estimated numbers of immigrants into small patches were lower in the landscape with intermediate forest cover compared to the most forested landscape. CONCLUSIONS/SIGNIFICANCE Our results reveal the crucial importance of the total amount of remaining native vegetation for species persistence in fragmented landscapes, and specifically as to the role of variable immigration rates in providing the underlying mechanism that drives both patch-area effects and species extinction thresholds.
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Affiliation(s)
- Thomas Püttker
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
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Promerová M, Babik W, Bryja J, Albrecht T, Stuglik M, Radwan J. Evaluation of two approaches to genotyping major histocompatibility complex class I in a passerine-CE-SSCP and 454 pyrosequencing. Mol Ecol Resour 2011; 12:285-92. [PMID: 22018268 DOI: 10.1111/j.1755-0998.2011.03082.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Genes of the highly dynamic major histocompatibility complex (MHC) are directly linked to individual fitness and are of high interest in evolutionary ecology and conservation genetics. Gene duplication and positive selection usually lead to high levels of polymorphism in the MHC region, making genotyping of MHC a challenging task. Here, we compare the performance of two methods for MHC class I genotyping in a passerine with highly duplicated MHC class I genes: capillary electrophoresis-single-strand conformation polymorphism (CE-SSCP) analysis and 454 GS FLX Titanium pyrosequencing. According to our findings, the number of MHC variants (called alleles for simplicity) detected by CE-SSCP is significantly lower than detected by 454. To resolve discrepancies between the two methods, we cloned and Sanger sequenced a MHC class I amplicon for an individual with high number of alleles. We found a perfect congruence between cloning/Sanger sequencing results and 454. Thus, in case of multi-locus amplification, CE-SSCP considerably underestimates individual MHC diversity. However, numbers of alleles detected by both methods are significantly correlated, although the correlation is weak (r = 0.32). Thus, in systems with highly duplicated MHC, 454 provides more reliable information on individual diversity than CE-SSCP.
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Affiliation(s)
- Marta Promerová
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 60365 Brno, Czech Republic.
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Bollmer JL, Hull JM, Ernest HB, Sarasola JH, Parker PG. Reduced MHC and neutral variation in the Galápagos hawk, an island endemic. BMC Evol Biol 2011; 11:143. [PMID: 21612651 PMCID: PMC3118149 DOI: 10.1186/1471-2148-11-143] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 05/25/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Genes at the major histocompatibility complex (MHC) are known for high levels of polymorphism maintained by balancing selection. In small or bottlenecked populations, however, genetic drift may be strong enough to overwhelm the effect of balancing selection, resulting in reduced MHC variability. In this study we investigated MHC evolution in two recently diverged bird species: the endemic Galápagos hawk (Buteo galapagoensis), which occurs in small, isolated island populations, and its widespread mainland relative, the Swainson's hawk (B. swainsoni). RESULTS We amplified at least two MHC class II B gene copies in each species. We recovered only three different sequences from 32 Galápagos hawks, while we amplified 20 unique sequences in 20 Swainson's hawks. Most of the sequences clustered into two groups in a phylogenetic network, with one group likely representing pseudogenes or nonclassical loci. Neutral genetic diversity at 17 microsatellite loci was also reduced in the Galápagos hawk compared to the Swainson's hawk. CONCLUSIONS The corresponding loss in neutral diversity suggests that the reduced variability present at Galápagos hawk MHC class II B genes compared to the Swainson's hawk is primarily due to a founder event followed by ongoing genetic drift in small populations. However, purifying selection could also explain the low number of MHC alleles present. This lack of variation at genes involved in the adaptive immune response could be cause for concern should novel diseases reach the archipelago.
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Affiliation(s)
- Jennifer L Bollmer
- Department of Biology, University of Missouri-St. Louis, One University Boulevard, St. Louis, MO 63121, USA
- Department of Biological Sciences, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Joshua M Hull
- Wildlife and Ecology Unit, Veterinary Genetics Laboratory, University of California, One Shields Avenue, Davis, CA 95616, USA
- Department of Animal Science, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Holly B Ernest
- Wildlife and Ecology Unit, Veterinary Genetics Laboratory, University of California, One Shields Avenue, Davis, CA 95616, USA
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - José H Sarasola
- Department of Evolutionary Ecology, Estación Biológica de Doñana, Avda. Américo Vespucio, 41092 Sevilla, Spain
| | - Patricia G Parker
- Department of Biology, University of Missouri-St. Louis, One University Boulevard, St. Louis, MO 63121, USA
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Jiménez FA, Catzeflis F, Gardner SL. Structure of parasite component communities of didelphid marsupials: insights from a comparative study. J Parasitol 2011; 97:779-87. [PMID: 21506798 DOI: 10.1645/ge-2711.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The parasite fauna of the gray four-eyed opossum, Philander opossum (Linnaeus, 1758), and the common opossum, Didelphis marsupialis Linnaeus, 1758, in Camp du Tigre, French Guiana, is characterized. Nine species from the gastrointestinal system were recovered from both species, which shared 80% of their parasites. The parasite fauna comprised several monoxenous species (63%) and was dominated by Aspidodera raillieti Travassos, 1914, which exhibited high levels of prevalence and abundance in both communities. Only 2 species (Moennigia sp. and Spirura guianensis) had been recorded in other species of mammals. Both species richness and taxonomic composition at the level of component communities from this locality were compared against 11 communities present in the Virginia ( Didelphis virginiana ), white-bellied (Didelphis albiventris), and common opossum from Argentina, Brazil, Mexico, and the United States. Neither host phylogeny nor taxonomy accounted for statistical differences in species richness. There was no statistical difference among species richness values among the 9 localities studied. Taxonomic similarity was analyzed by means of the Jaccard's similarity index, including all, and only common species (occurring in prevalence >10%). The results suggest that sympatric species of marsupials share more species of parasites than parasite communities occurring in conspecific marsupials from different localities. As a consequence, taxonomic composition of these parasite communities varied depending on the locality. Probably, marsupials of the monophyletic Didelphini offer the same compatibility toward their parasites, by presenting them with similar habitats. Subtle differences in lifestyles of the marsupials may determine the chance of encounter between the symbionts and prevent some parasites from completing their life cycles. Further and more rigorous tests are necessary to determine the roles of encounter and compatibility filters, as well as the role of chance, in the structuring of parasite communities in marsupials.
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Affiliation(s)
- F Agustín Jiménez
- Department of Zoology, Southern Illinois University, Carbondale, Illinois 62501-6501, USA.
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Cutrera AP, Zenuto RR, Lacey EA. MHC variation, multiple simultaneous infections and physiological condition in the subterranean rodent Ctenomys talarum. INFECTION GENETICS AND EVOLUTION 2011; 11:1023-36. [PMID: 21497205 DOI: 10.1016/j.meegid.2011.03.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 02/28/2011] [Accepted: 03/24/2011] [Indexed: 01/15/2023]
Abstract
Parasites and pathogens can play a significant role in shaping the genetic diversity of host populations, particularly at genes associated with host immune response. To explore this relationship in a natural population of vertebrates, we characterized Major Histocompatibility Complex (MHC) variation in the subterranean rodent Ctenomys talarum (the talas tuco-tuco) as a function of parasite load and ability to mount an adaptive immune response against a novel antigen. Specifically, we quantified genotypic diversity at the MHC class II DRB locus in relation to (1) natural variation in infection by multiple genera of parasites (potential agents of selection on MHC genes) and (2) antibody production in response to injection with sheep red blood cells (a measure of immunocompetence). Data were analyzed using co-inertia multivariate statistics, with epidemiological proxies for individual condition (hematocrit, leukocyte profile, body weight) and risk of parasite exposure (season of capture, sex). A significant excess of DRB heterozygotes was evident in the study population. Co-inertia analyses revealed significant associations between specific DRB alleles and both parasite load and intensity of humoral immune response against sheep red blood cells. The presence of specific DRB aminoacid sequences appeared to be more strongly associated with parasite load and response to a novel antigen than was heterozygosity at the DRB locus. These data suggest a role for parasite-driven balancing selection in maintaining MHC variation in natural populations of C. talarum. At the same time, these findings underscore the importance of using diverse parameters to study interactions among physiological conditions, immunocompetence, and MHC diversity in free-living animals that are confronted with multiple simultaneous immune challenges.
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Affiliation(s)
- Ana Paula Cutrera
- Laboratorio de Ecofisiología, Departamento de Biología, Universidad Nacional de Mar del Plata, CONICET, CC 1245, Mar del Plata, Argentina.
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Liu S, Chen F, Dai Y, Wu C, Ni Q, Yu W. Molecular characterization and tissue-specific expression of invariant chain in the muscovy duck (Cairina moschata). GENETICS AND MOLECULAR RESEARCH 2011; 10:2867-80. [DOI: 10.4238/2011.november.22.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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