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Olayemi A, Schmid DW, Fleischer R, Wilhelm K, Heni AC, Mueller-Klein N, Haikukutu L, Fichet-Calvet E, Günther S, Sommer S. MHC-I alleles mediate clearance and antibody response to the zoonotic Lassa virus in Mastomys rodent reservoirs. PLoS Negl Trop Dis 2024; 18:e0011984. [PMID: 38421939 PMCID: PMC10903922 DOI: 10.1371/journal.pntd.0011984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 02/09/2024] [Indexed: 03/02/2024] Open
Abstract
West African Mastomys rodents are the primary reservoir of the zoonotic Lassa virus (LASV). The virus causes haemorrhagic Lassa fever and considerable mortality in humans. To date, the role of Mastomys immunogenetics in resistance to, and persistence of, LASV infections is largely unknown. Here, we investigated the role of Major Histocompatibility Complex class I (MHC-I) on LASV infection status (i.e., active vs. cleared infection, determined via PCR and an immunofluorescence assay on IgG antibodies, respectively) in Mastomys natalensis and M. erythroleucus sampled within southwestern Nigeria. We identified more than 190 and 90 MHC-I alleles by Illumina high throughput-sequencing in M. natalensis and M. erythroleucus, respectively, with different MHC allele compositions and frequencies between LASV endemic and non-endemic sites. In M. natalensis, the MHC allele ManaMHC-I*006 was negatively associated with active infections (PCR-positive) and positively associated with cleared infections (IgG-positive) simultaneously, suggesting efficient immune responses that facilitate LASV clearance in animals carrying this allele. Contrarily, alleles ManaMHC-I*008 and ManaMHC-I*021 in M. natalensis, and MaerMHC-I*008 in M. erythroleucus, were positively associated with active infection, implying susceptibility. Alleles associated with susceptibility shared a glutamic acid at the positively selected codon 57, while ManaMHC-I*006 featured an arginine. There was no link between number of MHC alleles per Mastomys individual and LASV prevalence. Thus, specific alleles, but not MHC diversity per se, seem to mediate antibody responses to viremia. We conclude that co-evolution with LASV likely shaped the MHC-I diversity of the main LASV reservoirs in southwestern Nigeria, and that information on reservoir immunogenetics may hold insights into transmission dynamics and zoonotic spillover risks.
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Affiliation(s)
- Ayodeji Olayemi
- Natural History Museum, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria
| | - Dominik Werner 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
| | - Kerstin Wilhelm
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | | | - Nadine Mueller-Klein
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Lavinia Haikukutu
- Department of Wildlife Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Elisabeth Fichet-Calvet
- Department of Zoonoses Control, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stephan Günther
- Department of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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2
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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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Wild Boar (Sus scrofa)—Fascioloides magna Interaction from the Perspective of the MHC Genes. Pathogens 2022; 11:pathogens11111359. [DOI: 10.3390/pathogens11111359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 11/17/2022] Open
Abstract
Fascioloidosis is a parasitic disease caused by a trematode Fascioloides magna. Since major histocompatibility complex (MHC) genes play an important role in the immune response, the aim of this study was to compare the potential differences in MHC class II SLA-DRB1 exon 2 genes between wild boar populations from infected (cases) and non-infected areas (controls). During the winter of 2021, a total of 136 wild boar tissue samples were collected, 39 cases and 97 controls. DNA was extracted and sequenced using the Illumina platform. Differences in distributions of allele combinations were calculated using the Chi-Square test for homogeneity and between proportions using the large-sample test and Fisher–Irwin test. Analysis revealed 19 previously described swine leucocyte antigen (SLA) alleles. The number of polymorphic sites was 79 (29.6%), with 99 mutations in total. Nucleotide diversity π was estimated at 0.11. Proportions of the alleles SLA-DRB1*12:05 (p = 0.0008379) and SLA-DRB1*0101 (p = 0.0002825) were statistically significantly higher in controls, and proportions of the SLA-DRB1*0602 (p = 0.006059) and SLA-DRB1*0901 (p = 0.0006601) in cases. Alleles SLA-DRB1*04:09, SLA-DRB1*0501, SLA-DRB1*11:09, and SLA-DRB1*1301 were detected only in cases, while SLA-DRB1*0404, SLA-DRB1*0701, SLA-DRB1*02:10, and SLA-DRB1*04:08 were present only in controls. We did not confirm the existence of specific alleles that could be linked to F. magna infection. Detected high variability of the MHC class II SLA-DRB1 exon 2 genes indicate high resistance potential against various pathogens.
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Otto M, Zheng Y, Wiehe T. Recombination, selection and the evolution of tandem gene arrays. Genetics 2022; 221:6572811. [PMID: 35460227 PMCID: PMC9252282 DOI: 10.1093/genetics/iyac052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/17/2022] [Indexed: 11/16/2022] Open
Abstract
Multigene families—immunity genes or sensory receptors, for instance—are often subject to diversifying selection. Allelic diversity may be favored not only through balancing or frequency-dependent selection at individual loci but also by associating different alleles in multicopy gene families. Using a combination of analytical calculations and simulations, we explored a population genetic model of epistatic selection and unequal recombination, where a trade-off exists between the benefit of allelic diversity and the cost of copy abundance. Starting from the neutral case, where we showed that gene copy number is Gamma distributed at equilibrium, we derived also the mean and shape of the limiting distribution under selection. Considering a more general model, which includes variable population size and population substructure, we explored by simulations mean fitness and some summary statistics of the copy number distribution. We determined the relative effects of selection, recombination, and demographic parameters in maintaining allelic diversity and shaping the mean fitness of a population. One way to control the variance of copy number is by lowering the rate of unequal recombination. Indeed, when encoding recombination by a rate modifier locus, we observe exactly this prediction. Finally, we analyzed the empirical copy number distribution of 3 genes in human and estimated recombination and selection parameters of our model.
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Affiliation(s)
- Moritz Otto
- Institut für Genetik, Universität zu Köln, Zülpicher Straße 47a, 50674 Köln, Germany
| | - Yichen Zheng
- Institut für Genetik, Universität zu Köln, Zülpicher Straße 47a, 50674 Köln, Germany
| | - Thomas Wiehe
- Institut für Genetik, Universität zu Köln, Zülpicher Straße 47a, 50674 Köln, Germany
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Buzan E, Potušek S, Duniš L, Pokorny B. Neutral and Selective Processes Shape MHC Diversity in Roe Deer in Slovenia. Animals (Basel) 2022; 12:ani12060723. [PMID: 35327121 PMCID: PMC8944837 DOI: 10.3390/ani12060723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/23/2022] [Accepted: 03/10/2022] [Indexed: 12/21/2022] Open
Abstract
Simple Summary Disease prevention and appropriate wildlife management are among the major challenges in wildlife conservation. In the present study, we made a first assessment of the variability of major histocompatibility complex (MHC) genes in roe deer in Slovenia and evaluated local population adaptation by comparing MHC variability with neutral microsatellites. We discovered three new MHC DRB exon 2 alleles in addition to seven previously described in the literature. Moreover, we found evidence of historical positive selection, as selection analysis indicated that approx. 10% of the encoded amino acids were subjected to episodic positive selection. This study provides the basis for further research on immunogenetic variation in roe deer and highlights opportunities to incorporate genetic data into science-based population management. Abstract Disease control and containment in free-ranging populations is one of the greatest challenges in wildlife management. Despite the importance of major histocompatibility complex (MHC) genes for immune response, an assessment of the diversity and occurrence of these genes is still rare in European roe deer, the most abundant and widespread large mammal in Europe. Therefore, we examined immunogenetic variation in roe deer in Slovenia to identify species adaptation by comparing the genetic diversity of the MHC genes with the data on neutral microsatellites. We found ten MHC DRB alleles, three of which are novel. Evidence for historical positive selection on the MHC was found using the maximum likelihood codon method. Patterns of MHC allelic distribution were not congruent with neutral population genetic findings. The lack of population genetic differentiation in MHC genes compared to existing structure in neutral markers suggests that MHC polymorphism was influenced primarily by balancing selection and, to a lesser extent, by neutral processes such as genetic drift, with no clear evidence of local adaptation. Selection analyses indicated that approx. 10% of amino acids encoded under episodic positive selection. This study represents one of the first steps towards establishing an immunogenetic map of roe deer populations across Europe, aiming to better support science-based management of this important game species.
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Affiliation(s)
- Elena Buzan
- Faculty of Mathematics, Natural Sciences, and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia; (S.P.); (L.D.)
- Environmental Protection College, Trg Mladosti 7, 3320 Velenje, Slovenia;
- Correspondence: ; Tel.: +38-65-6117570; Fax: +38-65-61175
| | - Sandra Potušek
- Faculty of Mathematics, Natural Sciences, and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia; (S.P.); (L.D.)
| | - Luka Duniš
- Faculty of Mathematics, Natural Sciences, and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia; (S.P.); (L.D.)
| | - Boštjan Pokorny
- Environmental Protection College, Trg Mladosti 7, 3320 Velenje, Slovenia;
- Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, Slovenia
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Pineaux M, Merkling T, Danchin E, Hatch SA, Leclaire S, Blanchard P. MHC-II distance between parents predicts sex allocation decisions in a genetically monogamous bird. Behav Ecol 2021. [DOI: 10.1093/beheco/arab130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Theory predicts that parental heritable characteristics should shape sex allocation decisions when their effects on reproduction or survival are offspring sex-dependent. Numerous studies have questioned to what extent characteristics displayed by one of the parents matched theoretical expectations. This contrasts with the handful of studies that investigated whether compatibility between parents could also trigger selective pressures for sex allocation adjustments. We studied the genetically monogamous black-legged kittiwake (Rissa tridactyla), where previous data revealed that female chicks suffered higher fitness costs from low diversity at genes of the major histocompatibility complex (MHC) than male chicks. We predicted, and found in our dataset, that MHC-similar parents, producing low MHC-diverse offspring, should avoid the production of females. The relation between MHC-distance between parents (i.e. the functional distinctness of their MHC alleles) and offspring sex was not linear, such that MHC-dissimilar parents also overproduced sons. Overall, our results suggest that the genetically monogamous black-legged kittiwake parents flexibly adapt their reproduction and circumvent the costs of suboptimal pairing by manipulating offspring sex.
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Affiliation(s)
- Maxime Pineaux
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS. 118 route de Narbonne, Bât. 4R1, 31062 Toulouse cedex 9, France
| | - Thomas Merkling
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS. 118 route de Narbonne, Bât. 4R1, 31062 Toulouse cedex 9, France
| | - Etienne Danchin
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS. 118 route de Narbonne, Bât. 4R1, 31062 Toulouse cedex 9, France
| | - Scott A Hatch
- Institute for Seabird Research and Conservation, 12850 Mountain Place, Anchorage, AK 99516, USA
| | - Sarah Leclaire
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS. 118 route de Narbonne, Bât. 4R1, 31062 Toulouse cedex 9, France
| | - Pierrick Blanchard
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS. 118 route de Narbonne, Bât. 4R1, 31062 Toulouse cedex 9, France
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7
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Huang W, Dicks KL, Ballingall KT, Johnston SE, Sparks AM, Watt K, Pilkington JG, Pemberton JM. Associations between MHC class II variation and phenotypic traits in a free-living sheep population. Mol Ecol 2021; 31:902-915. [PMID: 34748666 DOI: 10.1111/mec.16265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 10/22/2021] [Accepted: 11/03/2021] [Indexed: 01/03/2023]
Abstract
Pathogen-mediated selection (PMS) is thought to maintain the high level of allelic diversity observed in the major histocompatibility complex (MHC) class II genes. A comprehensive way to demonstrate contemporary selection is to examine associations between MHC variation and individual fitness. As individual fitness is hard to measure, many studies examine associations between MHC variation and phenotypic traits, including direct or indirect measures of adaptive immunity thought to contribute to fitness. Here, we tested associations between MHC class II variation and five phenotypic traits measured in free-living sheep captured in August: weight, strongyle faecal egg count, and plasma IgA, IgE and IgG immunoglobulin titres against the gastrointestinal nematode parasite Teladorsagia circumcincta. We found no association between MHC class II variation and weight or strongyle faecal egg count. We did, however, find associations between MHC class II variation and immunoglobulin levels which varied with isotype, age and sex. Our results suggest associations between MHC and phenotypic traits are more likely to be found for traits more closely associated with pathogen defence than integrative traits such as bodyweight and highlight the association between MHC variation and antibodies in wild populations.
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Affiliation(s)
- Wei Huang
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Kara L Dicks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Susan E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Alexandra M Sparks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,School of Biology, University of Leeds, Leeds, UK
| | - Kathryn Watt
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Jill G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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8
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Talarico L, Marta S, Rossi AR, Crescenzo S, Petrosino G, Martinoli M, Tancioni L. Balancing selection, genetic drift, and human-mediated introgression interplay to shape MHC (functional) diversity in Mediterranean brown trout. Ecol Evol 2021; 11:10026-10041. [PMID: 34367556 PMCID: PMC8328470 DOI: 10.1002/ece3.7760] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 12/19/2022] Open
Abstract
The extraordinary polymorphism of major histocompatibility complex (MHC) genes is considered a paradigm of pathogen-mediated balancing selection, although empirical evidence is still scarce. Furthermore, the relative contribution of balancing selection to shape MHC population structure and diversity, compared to that of neutral forces, as well as its interaction with other evolutionary processes such as hybridization, remains largely unclear. To investigate these issues, we analyzed adaptive (MHC-DAB gene) and neutral (11 microsatellite loci) variation in 156 brown trout (Salmo trutta complex) from six wild populations in central Italy exposed to introgression from domestic hatchery lineages (assessed with the LDH gene). MHC diversity and structuring correlated with those at microsatellites, indicating the substantial role of neutral forces. However, individuals carrying locally rare MHC alleles/supertypes were in better body condition (a proxy of individual fitness/parasite load) regardless of the zygosity status and degree of sequence dissimilarity of MHC, hence supporting balancing selection under rare allele advantage, but not heterozygote advantage or divergent allele advantage. The association between specific MHC supertypes and body condition confirmed in part this finding. Across populations, MHC allelic richness increased with increasing admixture between native and domestic lineages, indicating introgression as a source of MHC variation. Furthermore, introgression across populations appeared more pronounced for MHC than microsatellites, possibly because initially rare MHC variants are expected to introgress more readily under rare allele advantage. Providing evidence for the complex interplay among neutral evolutionary forces, balancing selection, and human-mediated introgression in shaping the pattern of MHC (functional) variation, our findings contribute to a deeper understanding of the evolution of MHC genes in wild populations exposed to anthropogenic disturbance.
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Affiliation(s)
- Lorenzo Talarico
- Laboratory of Experimental Ecology and AquacultureDepartment of BiologyUniversity of Rome “Tor Vergata”RomeItaly
| | - Silvio Marta
- Department of Environmental Science and PolicyUniversity of MilanMilanItaly
| | - Anna Rita Rossi
- Department of Biology and Biotechnology C. DarwinUniversity of Rome “La Sapienza”RomeItaly
| | - Simone Crescenzo
- Department of Biology and Biotechnology C. DarwinUniversity of Rome “La Sapienza”RomeItaly
| | - Gerardo Petrosino
- Department of Biology and Biotechnology C. DarwinUniversity of Rome “La Sapienza”RomeItaly
| | - Marco Martinoli
- Laboratory of Experimental Ecology and AquacultureDepartment of BiologyUniversity of Rome “Tor Vergata”RomeItaly
- Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria (CREA)Centro di Zootecnia e AcquacolturaMonterotondoItaly
| | - Lorenzo Tancioni
- Laboratory of Experimental Ecology and AquacultureDepartment of BiologyUniversity of Rome “Tor Vergata”RomeItaly
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Scherman K, Råberg L, Westerdahl H. Borrelia Infection in Bank Voles Myodes glareolus Is Associated With Specific DQB Haplotypes Which Affect Allelic Divergence Within Individuals. Front Immunol 2021; 12:703025. [PMID: 34381454 PMCID: PMC8350566 DOI: 10.3389/fimmu.2021.703025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/01/2021] [Indexed: 11/17/2022] Open
Abstract
The high polymorphism of Major Histocompatibility Complex (MHC) genes is generally considered to be a result of pathogen-mediated balancing selection. Such selection may operate in the form of heterozygote advantage, and/or through specific MHC allele–pathogen interactions. Specific MHC allele–pathogen interactions may promote polymorphism via negative frequency-dependent selection (NFDS), or selection that varies in time and/or space because of variability in the composition of the pathogen community (fluctuating selection; FS). In addition, divergent allele advantage (DAA) may act on top of these forms of balancing selection, explaining the high sequence divergence between MHC alleles. DAA has primarily been thought of as an extension of heterozygote advantage. However, DAA could also work in concert with NFDS though this is yet to be tested explicitly. To evaluate the importance of DAA in pathogen-mediated balancing selection, we surveyed allelic polymorphism of MHC class II DQB genes in wild bank voles (Myodes glareolus) and tested for associations between DQB haplotypes and infection by Borrelia afzelii, a tick-transmitted bacterium causing Lyme disease in humans. We found two significant associations between DQB haplotypes and infection status: one haplotype was associated with lower risk of infection (resistance), while another was associated with higher risk of infection (susceptibility). Interestingly, allelic divergence within individuals was higher for voles with the resistance haplotype compared to other voles. In contrast, allelic divergence was lower for voles with the susceptibility haplotype than other voles. The pattern of higher allelic divergence in individuals with the resistance haplotype is consistent with NFDS favouring divergent alleles in a natural population, hence selection where DAA works in concert with NFDS.
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Affiliation(s)
- Kristin Scherman
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Lars Råberg
- Functional Zoology, Department of Biology, Lund University, Lund, Sweden
| | - Helena Westerdahl
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
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10
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Stefanović M, Ćirović D, Bogdanović N, Knauer F, Heltai M, Szabó L, Lanszki J, Zhelev CD, Schaschl H, Suchentrunk F. Positive selection on the MHC class II DLA-DQA1 gene in golden jackals (Canis aureus) from their recent expansion range in Europe and its effect on their body mass index. BMC Ecol Evol 2021; 21:122. [PMID: 34134625 PMCID: PMC8207625 DOI: 10.1186/s12862-021-01856-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 06/10/2021] [Indexed: 11/17/2022] Open
Abstract
Background In Europe, golden jackals (Canis aureus) have been expanding their range out of the southern and southeastern Balkans towards central Europe continually since the 1960s. Here, we investigated the level of functional diversity at the MHC class II DLA-DQA1 exon 2 in golden jackal populations from Bulgaria, Serbia, and Hungary. Specifically, we tested for positive selection on and geographic variation at that locus due to adaptation to supposedly regionally varying pathogenic landscapes. To test for potential fitness effects of different protein variants on individual body condition, we used linear modeling of individual body mass indexes (bmi) and accounted for possible age, sex, geographical, and climatic effects. The latter approach was performed, however, only on Serbian individuals with appropriate data. Results Only three different DLA-DQA1 alleles were detected, all coding for different amino-acid sequences. The neutrality tests revealed no significant but positive values; there was no signal of spatial structuring and no deviation from the Hardy–Weinberg equilibrium across the studied range of expansion. However, we found a signal of trans-species polymorphism and significant test results for positive selection on three codons. Our information-theory based linear modeling results indicated an effect of ambient temperature on the occurrence of individual DLA-DQA1 genotypes in individuals from across the studied expansion range, independent from geographical position. Our linear modeling results of individual bmi values indicated that yearlings homozygous for DLA-DQA1*03001 reached values typical for adults contrary to yearlings carrying other genotypes (protein combinations). This suggested better growth rates and thus a possible fitness advantage of yearlings homozygous for DLA-DQA1*03001. Conclusions Our results indicate a demographic (stochastic) signal of reduced DLA-DQA1 exon 2 variation, in line with the documented historical demographic bottleneck. At the same time, however, allelic variation was also affected by positive selection and adaptation to varying ambient temperature, supposedly reflecting geographic variation in the pathogenic landscape. Moreover, an allele effect on body mass index values of yearlings suggested differential fitness associated with growth rates. Overall, a combination of a stochastic effect and positive selection has shaped and is still shaping the variation at the studied MHC locus. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01856-z.
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Affiliation(s)
- Milomir Stefanović
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 2, 21000, Novi Sad, Serbia.,Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria
| | - Duško Ćirović
- Faculty of Biology, University of Belgrade, Studentski trg 16, 11000, Belgrade, Serbia
| | - Neda Bogdanović
- Faculty of Biology, University of Belgrade, Studentski trg 16, 11000, Belgrade, Serbia
| | - Felix Knauer
- Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria
| | - Miklós Heltai
- Institute for Wildlife Conservation, Szent István University, Páter Károly utca 1, Gödöllő, 2100, Hungary
| | - László Szabó
- Institute for Wildlife Conservation, Szent István University, Páter Károly utca 1, Gödöllő, 2100, Hungary
| | - József Lanszki
- Ecological Research Group, University of Kaposvár, PO Box 16, 7401, Kaposvár, Hungary
| | | | - Helmut Schaschl
- Department of Evolutionary Anthropology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
| | - Franz Suchentrunk
- Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstrasse 1, 1160, Vienna, Austria
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11
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Rödel HG, Oppelt C, Starkloff A, Prager N, Long E, Rüdiger AT, Seltmann MW, Monclús R, Hudson R, Poteaux C. Within-litter covariance of allele-specific MHC heterozygosity, coccidian endoparasite load and growth is modulated by sibling differences in starting mass. Oecologia 2020; 194:345-357. [PMID: 32980896 DOI: 10.1007/s00442-020-04764-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 09/19/2020] [Indexed: 10/23/2022]
Abstract
Although littermates in altricial mammals usually experience highly similar environmental conditions during early life, considerable differences in growth and health can emerge among them. In a study on subadults of a European rabbit (Oryctolagus cuniculus) population with low MHC polymorphism, we tested whether litter-sibling differences in endoparasitic coccidia load and body mass at the end of the vegetation period were associated with within-litter differences in starting body mass (measured around 2 weeks prior to weaning) and in immune-genetic (MHC class II DRB) constitution. We hypothesized that siblings with a lighter starting mass might be more susceptible to endoparasite infections and thus, negative effects of a more unfavourable MHC constitution might be particularly pronounced in such individuals. Within-litter comparisons revealed that animals with a lighter starting mass reached a relatively lower body mass in autumn. Furthermore, there were indications for an allele-specific heterozygote advantage, as animals with heterozygous combinations of the allele Orcu-DRB*4 had relatively lower hepatic coccidia loads than their littermates with certain homozygous allele combinations. Consistent with our hypothesis, significantly higher hepatic coccidia loads and tendentially lower autumn body masses in homozygous compared to heterozygous individuals for the allele Orcu-DRB*4 were evident in initially lighter but not in heavier siblings, suggesting synergistic effects between an unfavourable MHC constitution and a light starting mass. Taken together, these effects might lead to notable differences in fitness among litter siblings, as a low body mass and a high endoparasite burden are key factors limiting young rabbits' survival during winter.
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Affiliation(s)
- Heiko G Rödel
- Laboratoire d'Ethologie Expérimentale et Comparée UR 4443, Université Sorbonne Paris Nord, 93430, Villetaneuse, France. .,Department of Animal Physiology, University of Bayreuth, 95440, Bayreuth, Germany.
| | - Claus Oppelt
- Department of Animal Physiology, University of Bayreuth, 95440, Bayreuth, Germany
| | - Anett Starkloff
- Department of Animal Physiology, University of Bayreuth, 95440, Bayreuth, Germany
| | - Nelly Prager
- Laboratoire d'Ethologie Expérimentale et Comparée UR 4443, Université Sorbonne Paris Nord, 93430, Villetaneuse, France
| | - Emilie Long
- Laboratoire d'Ethologie Expérimentale et Comparée UR 4443, Université Sorbonne Paris Nord, 93430, Villetaneuse, France
| | - Anna-Theresa Rüdiger
- Department of Animal Physiology, University of Bayreuth, 95440, Bayreuth, Germany
| | - Martin W Seltmann
- Department of Animal Physiology, University of Bayreuth, 95440, Bayreuth, Germany.,Department of Biology, University of Turku, 20014, Turku, Finland
| | - Raquel Monclús
- Laboratoire d'Ethologie Expérimentale et Comparée UR 4443, Université Sorbonne Paris Nord, 93430, Villetaneuse, France
| | - Robyn Hudson
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - Chantal Poteaux
- Laboratoire d'Ethologie Expérimentale et Comparée UR 4443, Université Sorbonne Paris Nord, 93430, Villetaneuse, France
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12
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Liu C, Lei H, Ran X, Wang J. Genetic variation and selection in the major histocompatibility complex Class II gene in the Guizhou pony. PeerJ 2020; 8:e9889. [PMID: 32999762 PMCID: PMC7505079 DOI: 10.7717/peerj.9889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 08/17/2020] [Indexed: 11/20/2022] Open
Abstract
The Guizhou pony (GZP) is an indigenous species of equid found in the mountains of the Guizhou province in southwest China. We selected four regions of the equine leukocyte antigen (ELA), including DQA, DRA, DQB, and DRB, and used them to assess the diversity of the major histocompatibility complex (MHC) class II gene using direct sequencing technology. DRA had the lowest dN/dS ratio (0.560) compared with the other three loci, indicating that DRA was conserved and could be conserved after undergoing selective processes. Nine DQA, five DQB, nine DRA, and seven DRB codons were under significant positive selection at the antigen binding sites (ABS), suggesting that the selected residues in ABS may play a significant role in the innate immune system of the GZP. Two GZP alleles were shared with Przewalski’s horse, and six older GZP haplotypes had a better relationship with other horse species by one or two mutational steps, indicating that the GZP may be a natural ancient variety of equid. The specific diversity of ABS and the numbers of unique haplotypes in the evolutionary process affords this species a better genetic fitness and ability to adapt to the native environment.
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Affiliation(s)
- Chang Liu
- College of Animal Sciences, Guizhou University, Guiyang, China.,College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Hongmei Lei
- College of Animal Sciences, Guizhou University, Guiyang, China
| | - Xueqin Ran
- College of Animal Sciences, Guizhou University, Guiyang, China
| | - Jiafu Wang
- College of Animal Sciences, Guizhou University, Guiyang, China.,Tongren University, Tongren, China
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13
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Pineaux M, Merkling T, Danchin E, Hatch S, Duneau D, Blanchard P, Leclaire S. Sex and hatching order modulate the association between MHC-II diversity and fitness in early-life stages of a wild seabird. Mol Ecol 2020; 29:3316-3329. [PMID: 32654215 DOI: 10.1111/mec.15551] [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] [Received: 09/11/2019] [Revised: 07/04/2020] [Accepted: 07/06/2020] [Indexed: 01/04/2023]
Abstract
Genes of the major histocompatibility complex (MHC) play a pivotal role in parasite resistance, and their allelic diversity has been associated with fitness variations in several taxa. However, studies report inconsistencies in the direction of this association, with either positive, quadratic or no association being described. These discrepancies may arise because the fitness costs and benefits of MHC diversity differ among individuals depending on their exposure and immune responses to parasites. Here, we investigated in black-legged kittiwake (Rissa tridactyla) chicks whether associations between MHC class-II diversity and fitness vary with sex and hatching order. MHC-II diversity was positively associated with growth and tick clearance in female chicks, but not in male chicks. Our data also revealed a positive association between MHC-II diversity and survival in second-hatched female chicks (two eggs being the typical clutch size). These findings may result from condition-dependent parasite infections differentially impacting sexes in relation to hatching order. We thus suggest that it may be important to account for individual heterogeneities in traits that potentially exert selective pressures on MHC diversity in order to properly predict MHC-fitness associations.
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Affiliation(s)
- Maxime Pineaux
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, Université Fédérale de Toulouse Midi-Pyrénées, Toulouse, France
| | - Thomas Merkling
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, Université Fédérale de Toulouse Midi-Pyrénées, Toulouse, France
| | - Etienne Danchin
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, Université Fédérale de Toulouse Midi-Pyrénées, Toulouse, France
| | - Scott Hatch
- Institute for Seabird Research and Conservation, Anchorage, AK, USA
| | - David Duneau
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, Université Fédérale de Toulouse Midi-Pyrénées, Toulouse, France
| | - Pierrick Blanchard
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, Université Fédérale de Toulouse Midi-Pyrénées, Toulouse, France
| | - Sarah Leclaire
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, Université Fédérale de Toulouse Midi-Pyrénées, Toulouse, France
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14
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Pathogen-associated selection on innate immunity genes (TLR4, TLR7) in a neotropical rodent in landscapes differing in anthropogenic disturbance. Heredity (Edinb) 2020; 125:184-199. [PMID: 32616896 PMCID: PMC7490709 DOI: 10.1038/s41437-020-0331-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 01/10/2023] Open
Abstract
Toll-like receptors (TLRs) form part of the innate immune system and can recognize structurally conserved pathogen-associated molecular pattern (PAMP) molecules. Their functional importance in the resistance to pathogens has been documented in laboratory experimental settings and in humans. TLR diversity, however, has been rarely investigated in wildlife species. How the genetic diversity of TLRs is associated with various pathogens and how it is shaped by habitat disturbance are understudied. Therefore, we investigated the role of genetic diversity in the functionally important parts of TLR4 and TLR7 genes in resistance towards gastrointestinal nematodes and Hepacivirus infection. We chose a generalist study species, the rodent Proechimys semispinosus, because it is highly abundant in three Panamanian landscapes that differ in their degree of anthropogenic modification. We detected only two TLR7 haplotypes that differed by one synonymous single-nucleotide polymorphism (SNP) position. The TLR4 variability was higher, and we detected four TLR4 haplotypes that differed at one synonymous SNP and at three amino acid positions within the leucine-rich repeat region. Only TLR4 haplotypes had different frequencies in each landscape. Using generalized linear models, we found evidence that nematode loads and virus prevalence were influenced by both specific TLR4 haplotypes and landscape. Here, the variable “landscape” served as a surrogate for the important influential ecological factors distinguishing landscapes in our study, i.e. species diversity and host population density. Individuals carrying the common TLR4_Ht1 haplotype were less intensely infected by the most abundant strongyle nematode. Individuals carrying the rare TLR4_Ht3 haplotype were all Hepacivirus-positive, where those carrying the rare haplotype TLR4_Ht4 were less often infected by Hepacivirus than individuals with other haplotypes. Our study highlights the role of TLR diversity in pathogen resistance and the importance of considering immune genetic as well as ecological factors in order to understand the effects of anthropogenic changes on wildlife health.
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15
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Arora J, Pierini F, McLaren PJ, Carrington M, Fellay J, Lenz TL. HLA Heterozygote Advantage against HIV-1 Is Driven by Quantitative and Qualitative Differences in HLA Allele-Specific Peptide Presentation. Mol Biol Evol 2020; 37:639-650. [PMID: 31651980 PMCID: PMC7038656 DOI: 10.1093/molbev/msz249] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pathogen-mediated balancing selection is regarded as a key driver of host immunogenetic diversity. A hallmark for balancing selection in humans is the heterozygote advantage at genes of the human leukocyte antigen (HLA), resulting in improved HIV-1 control. However, the actual mechanism of the observed heterozygote advantage is still elusive. HLA heterozygotes may present a broader array of antigenic viral peptides to immune cells, possibly resulting in a more efficient cytotoxic T-cell response. Alternatively, heterozygosity may simply increase the chance to carry the most protective HLA alleles, as individual HLA alleles are known to differ substantially in their association with HIV-1 control. Here, we used data from 6,311 HIV-1-infected individuals to explore the relative contribution of quantitative and qualitative aspects of peptide presentation in HLA heterozygote advantage against HIV. Screening the entire HIV-1 proteome, we observed that heterozygous individuals exhibited a broader array of HIV-1 peptides presented by their HLA class I alleles. In addition, viral load was negatively correlated with the breadth of the HIV-1 peptide repertoire bound by an individual's HLA variants, particularly at HLA-B. This suggests that heterozygote advantage at HLA-B is at least in part mediated by quantitative peptide presentation. We also observed higher HIV-1 sequence diversity among HLA-B heterozygous individuals, suggesting stronger evolutionary pressure from HLA heterozygosity. However, HLA heterozygotes were also more likely to carry certain HLA alleles, including the highly protective HLA-B*57:01 variant, indicating that HLA heterozygote advantage ultimately results from a combination of quantitative and qualitative effects in antigen presentation.
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Affiliation(s)
- Jatin Arora
- Research Group for Evolutionary Immunogenomics, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Federica Pierini
- Research Group for Evolutionary Immunogenomics, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Paul J McLaren
- JC Wilt Infectious Diseases Research Center, National HIV and Retrovirology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Mary Carrington
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA
| | - Jacques Fellay
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Precision Medicine Unit, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Tobias L Lenz
- Research Group for Evolutionary Immunogenomics, Max Planck Institute for Evolutionary Biology, Plön, Germany
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16
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Pierini F, Lenz TL. Divergent Allele Advantage at Human MHC Genes: Signatures of Past and Ongoing Selection. Mol Biol Evol 2020; 35:2145-2158. [PMID: 29893875 PMCID: PMC6106954 DOI: 10.1093/molbev/msy116] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The highly polymorphic genes of the major histocompatibility complex (MHC) play a key role in adaptive immunity. Divergent allele advantage, a mechanism of balancing selection, is proposed to contribute to their exceptional polymorphism. It assumes that MHC genotypes with more divergent alleles allow for broader antigen-presentation to immune effector cells, by that increasing immunocompetence. However, the direct correlation between pairwise sequence divergence and the corresponding repertoire of bound peptides has not been studied systematically across different MHC genes. Here, we investigated this relationship for five key classical human MHC genes (human leukocyte antigen; HLA-A, -B, -C, -DRB1, and -DQB1), using allele-specific computational binding prediction to 118,097 peptides derived from a broad range of human pathogens. For all five human MHC genes, the genetic distance between two alleles of a heterozygous genotype was positively correlated with the total number of peptides bound by these two alleles. In accordance with the major antigen-presentation pathway of MHC class I molecules, HLA-B and HLA-C alleles showed particularly strong correlations for peptides derived from intracellular pathogens. Intriguingly, this bias coincides with distinct protein compositions between intra- and extracellular pathogens, possibly suggesting adaptation of MHC I molecules to present specifically intracellular peptides. Eventually, we observed significant positive correlations between an allele’s average divergence and its population frequency. Overall, our results support the divergent allele advantage as a meaningful quantitative mechanism through which pathogen-mediated selection leads to the evolution of MHC diversity.
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Affiliation(s)
- Federica Pierini
- Research Group for Evolutionary Immunogenomics, Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Ploen, Germany
| | - Tobias L Lenz
- Research Group for Evolutionary Immunogenomics, Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Ploen, Germany
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17
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Becker DJ, Albery GF, Kessler MK, Lunn TJ, Falvo CA, Czirják GÁ, Martin LB, Plowright RK. Macroimmunology: The drivers and consequences of spatial patterns in wildlife immune defence. J Anim Ecol 2020; 89:972-995. [PMID: 31856309 DOI: 10.1111/1365-2656.13166] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 11/06/2019] [Indexed: 01/26/2023]
Abstract
The prevalence and intensity of parasites in wild hosts varies across space and is a key determinant of infection risk in humans, domestic animals and threatened wildlife. Because the immune system serves as the primary barrier to infection, replication and transmission following exposure, we here consider the environmental drivers of immunity. Spatial variation in parasite pressure, abiotic and biotic conditions, and anthropogenic factors can all shape immunity across spatial scales. Identifying the most important spatial drivers of immunity could help pre-empt infectious disease risks, especially in the context of how large-scale factors such as urbanization affect defence by changing environmental conditions. We provide a synthesis of how to apply macroecological approaches to the study of ecoimmunology (i.e. macroimmunology). We first review spatial factors that could generate spatial variation in defence, highlighting the need for large-scale studies that can differentiate competing environmental predictors of immunity and detailing contexts where this approach might be favoured over small-scale experimental studies. We next conduct a systematic review of the literature to assess the frequency of spatial studies and to classify them according to taxa, immune measures, spatial replication and extent, and statistical methods. We review 210 ecoimmunology studies sampling multiple host populations. We show that whereas spatial approaches are relatively common, spatial replication is generally low and unlikely to provide sufficient environmental variation or power to differentiate competing spatial hypotheses. We also highlight statistical biases in macroimmunology, in that few studies characterize and account for spatial dependence statistically, potentially affecting inferences for the relationships between environmental conditions and immune defence. We use these findings to describe tools from geostatistics and spatial modelling that can improve inference about the associations between environmental and immunological variation. In particular, we emphasize exploratory tools that can guide spatial sampling and highlight the need for greater use of mixed-effects models that account for spatial variability while also allowing researchers to account for both individual- and habitat-level covariates. We finally discuss future research priorities for macroimmunology, including focusing on latitudinal gradients, range expansions and urbanization as being especially amenable to large-scale spatial approaches. Methodologically, we highlight critical opportunities posed by assessing spatial variation in host tolerance, using metagenomics to quantify spatial variation in parasite pressure, coupling large-scale field studies with small-scale field experiments and longitudinal approaches, and applying statistical tools from macroecology and meta-analysis to identify generalizable spatial patterns. Such work will facilitate scaling ecoimmunology from individual- to habitat-level insights about the drivers of immune defence and help predict where environmental change may most alter infectious disease risk.
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Affiliation(s)
- Daniel J Becker
- Department of Biology, Indiana University, Bloomington, IN, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Gregory F Albery
- Department of Biology, Georgetown University, Washington, DC, USA
| | | | - Tamika J Lunn
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland, Australia
| | - Caylee A Falvo
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Lynn B Martin
- Department of Global and Planetary Health, University of South Florida, Tampa, FL, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
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18
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Talarico L, Babik W, Marta S, Pietrocini V, Mattoccia M. MHC structuring and divergent allele advantage in a urodele amphibian: a hierarchical multi-scale approach. Heredity (Edinb) 2019; 123:593-607. [PMID: 31036951 PMCID: PMC6972932 DOI: 10.1038/s41437-019-0221-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/31/2019] [Accepted: 03/31/2019] [Indexed: 12/27/2022] Open
Abstract
Proteins encoded by extraordinarily polymorphic major histocompatibility complex (MHC) genes are involved in the adaptive immune response. Balancing selection is believed to maintain MHC polymorphism in the long term, although neutral processes also play a role in shaping MHC diversity. However, the relative contribution of these processes is poorly understood. Here we characterized MHC class II variation of a low-dispersal, pond-breeding newt (Triturus carnifex) over a restricted, geographically structured area. We aimed to (1) evaluate the contribution of selection and neutral processes to shaping MHC diversity at two geographic scales, and (2) test for signatures of divergent allele advantage (DAA), which is a potentially important mechanism of balancing selection. The dominant role of selection in shaping MHC variation was suggested by the lack of correlation between MHC and neutral (microsatellite) variation. Although most variation occurred within populations for both types of markers, they differed in the extent of structuring at the two spatial scales. MHC structuring was more pronounced at local scales, suggesting the role of local selection, while structuring was not detectable at a larger scale, possibly due to the effect of balancing selection. Microsatellites showed the opposite pattern. As expected under DAA, the observed genotypes combined more sequence diversity than expected under a random association of alleles. Thus, DAA may contribute to maintaining MHC polymorphism, which is ancient, as supported by signatures of historical positive selection and trans-species polymorphism. Our results point to the importance of a multi-scale approach in studying MHC variation, especially in low-dispersal taxa, which are genetically structured at fine spatial scales.
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Affiliation(s)
- Lorenzo Talarico
- Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, Rome, 00133, Italy.
| | - Wiesław Babik
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Kraków, 30-387, Poland
| | - Silvio Marta
- Department of Environmental Sciences and Policy, University of Milan, Via G. Celoria 26, Milan, 20133, Italy
| | - Venusta Pietrocini
- Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, Rome, 00133, Italy
| | - Marco Mattoccia
- Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, Rome, 00133, Italy
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19
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Pérez-Espona S, Goodall-Copestake WP, Savirina A, Bobovikova J, Molina-Rubio C, Pérez-Barbería FJ. First assessment of MHC diversity in wild Scottish red deer populations. EUR J WILDLIFE RES 2019. [DOI: 10.1007/s10344-019-1254-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Abts KC, Ivy JA, DeWoody JA. Demographic, environmental and genetic determinants of mating success in captive koalas (Phascolarctos cinereus). Zoo Biol 2018; 37:416-433. [PMID: 30488502 DOI: 10.1002/zoo.21457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/29/2018] [Accepted: 10/22/2018] [Indexed: 01/26/2023]
Abstract
Many factors have been shown to affect mating behavior. For instance, genes of the major histocompatibility complex (MHC) are known to influence mate choice in a wide variety of vertebrate species. The genetic management of captive populations can be confounded if intrinsic mate choice reduces or eliminates reproductive success between carefully chosen breeding pairs. For example, the San Diego Zoo koala colony only has a 45% copulation rate for matched individuals. Herein, we investigated determinants of koala mating success using breeding records (1984-2010) and genotypes for 52 individuals at four MHC markers. We quantified MHC diversity according to functional amino acids, heterozygosity, and the probability of producing a heterozygous offspring. We then used categorical analysis and logistic regression to investigate both copulation and parturition success. In addition, we also examined age, day length, and average pairwise kinship. Our post-hoc power analysis indicates that at a power level of 1-β = 0.8, we should have been able to detect strong MHC preferences. However, we did not find a significant MHC effect on either copulation or parturition success with one exception: pairs with lower or no production of a joey had significantly lower MHC functional amino acid diversity in the categorical analysis. In contrast, day length and dam age (or age difference of the pair) consistently had an effect on mating success. These findings may be leveraged to improve the success of attempted pairs, conserve resources, and facilitate genetic management.
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Affiliation(s)
- Kendra C Abts
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana
| | | | - J Andrew DeWoody
- Departments of Forestry and Natural Resources and Biological Sciences, Purdue University, West Lafayette, Indiana
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21
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Yu L, Nie Y, Yan L, Hu Y, Wei F. No evidence for MHC-based mate choice in wild giant pandas. Ecol Evol 2018; 8:8642-8651. [PMID: 30271533 PMCID: PMC6157678 DOI: 10.1002/ece3.4419] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 07/02/2018] [Accepted: 07/04/2018] [Indexed: 11/10/2022] Open
Abstract
Major histocompatibility complex genes (MHC), a gene cluster that controls the immune response to parasites, are regarded as an important determinant of mate choice. However, MHC-based mate choice studies are especially rare for endangered animals. The giant panda (Ailuropoda melanoleuca), a flagship species, has suffered habitat loss and fragmentation. We investigated the genetic variation of three MHC class II loci, including DRB1, DQA1, and DQA2, for 19 mating-pairs and 11 parent-pairs of wild giant pandas based on long-term field behavior observations and genetic samples. We tested four hypotheses of mate choice based on this MHC variation. We found no supporting evidence for the MHC-based heterosis, genetic diversity, genetic compatibility and "good gene" hypotheses. These results suggest that giant pandas may not use MHC-based signals to select mating partners, probably because limited mating opportunities or female-biased natal dispersal restricts selection for MHC-based mate choice, acknowledging the caveat of the small sample size often encountered in endangered animal studies. Our study provides insight into the mate choice mechanisms of wild giant pandas and highlights the need to increase the connectivity and facilitate dispersal among fragmented populations and habitats.
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Affiliation(s)
- Lijun Yu
- CAS Key Laboratory of Animal Ecology and Conservation BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yonggang Nie
- CAS Key Laboratory of Animal Ecology and Conservation BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Center for Excellence in Animal Evolution and GeneticsChinese Academy of SciencesKunmingChina
| | - Li Yan
- CAS Key Laboratory of Animal Ecology and Conservation BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
| | - Yibo Hu
- CAS Key Laboratory of Animal Ecology and Conservation BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- Center for Excellence in Animal Evolution and GeneticsChinese Academy of SciencesKunmingChina
| | - Fuwen Wei
- CAS Key Laboratory of Animal Ecology and Conservation BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
- Center for Excellence in Animal Evolution and GeneticsChinese Academy of SciencesKunmingChina
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22
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Hernández-Gómez O, Briggler JT, Williams RN. Influence of immunogenetics, sex and body condition on the cutaneous microbial communities of two giant salamanders. Mol Ecol 2018; 27:1915-1929. [PMID: 29411437 DOI: 10.1111/mec.14500] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 02/06/2023]
Abstract
The complex association between hosts and microbial symbionts requires the implementation of multiple approaches to evaluate variation in host physiology. Within amphibians, heterogeneity in immunogenetic traits and cutaneous microbiota is associated with variation in disease resistance. Ozark (Cryptobranchus alleganiensis bishopi) and eastern hellbenders (C. a. alleganiensis) provide a model system to assess variation in host traits and microbial communities. Ozark hellbenders have experienced declines throughout their range, are federally endangered and experience wound retardation that is absent in the eastern subspecies. Previous microbial investigations indicate differentiation in the composition of the skin microbiota of both hellbender subspecies, but it is not clear whether these patterns are concurrent with diversity in the major histocompatibility complex (MHC) genes. We characterized the MHC IIB and the skin microbiota of hellbenders in Missouri, where both subspecies co-occur though not sympatric. We compared the microbiota composition and MHC diversity between both subspecies and investigated whether individual-level MHC diversity, sex and body condition were associated with microbiota composition. Overall, MHC IIB diversity was lower in Ozark hellbenders compared to the eastern subspecies. Multivariate statistical comparisons identified microbiota differentiation between Ozark and eastern hellbenders. MHC IIB allele presence/absence, allele divergence, body composition and sex defined grouping of hellbender microbiotas within populations. Differentiation of the cutaneous microbiotas and MHC IIB genes between eastern and Ozark hellbenders suggests that differences exist in immunity between the two subspecies. This study demonstrates how simultaneous assessments of host genetic traits and microbiotas can inform patterns of microbial community structure in natural systems.
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Affiliation(s)
- Obed Hernández-Gómez
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
| | | | - Rod N Williams
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
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Lack of evidence for selection favouring MHC haplotypes that combine high functional diversity. Heredity (Edinb) 2018; 120:396-406. [PMID: 29362475 DOI: 10.1038/s41437-017-0047-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 02/02/2023] Open
Abstract
High rates of gene duplication and the highest levels of functional allelic diversity in vertebrate genomes are the main hallmarks of the major histocompatibility complex (MHC), a multigene family with a primordial role in pathogen recognition. The usual tight linkage among MHC gene duplicates may provide an opportunity for the evolution of haplotypes that associate functionally divergent alleles and thus grant the transmission of optimal levels of diversity to coming generations. Even though such associations may be a crucial component of disease resistance, this hypothesis has been given little attention in wild populations. Here, we leveraged pedigree data from a barn owl (Tyto alba) population to characterize MHC haplotype structure across two MHC class I (MHC-I) and two MHC class IIB (MHC-IIB) duplicates, in order to test the hypothesis that haplotypes' genetic diversity is higher than expected from randomly associated alleles. After showing that MHC loci are tightly linked within classes, we found limited evidence for shifts towards MHC haplotypes combining high diversity. Neither amino acid nor functional within-haplotype diversity were significantly higher than in random sets of haplotypes, regardless of MHC class. Our results therefore provide no evidence for selection towards high-diversity MHC haplotypes in barn owls. Rather, high rates of concerted evolution may constrain the evolution of high-diversity haplotypes at MHC-I, while, in contrast, for MHC-IIB, fixed differences among loci may provide barn owls with already optimized functional diversity. This suggests that at the MHC-I and MHC-IIB respectively, different evolutionary dynamics may govern the evolution of within-haplotype diversity.
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Lighten J, Papadopulos AST, Mohammed RS, Ward BJ, G Paterson I, Baillie L, Bradbury IR, Hendry AP, Bentzen P, van Oosterhout C. Evolutionary genetics of immunological supertypes reveals two faces of the Red Queen. Nat Commun 2017; 8:1294. [PMID: 29101318 PMCID: PMC5670221 DOI: 10.1038/s41467-017-01183-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 08/23/2017] [Indexed: 11/09/2022] Open
Abstract
Red Queen host-parasite co-evolution can drive adaptations of immune genes by positive selection that erodes genetic variation (Red Queen arms race) or results in a balanced polymorphism (Red Queen dynamics) and long-term preservation of genetic variation (trans-species polymorphism). These two Red Queen processes are opposite extremes of the co-evolutionary spectrum. Here we show that both Red Queen processes can operate simultaneously by analysing the major histocompatibility complex (MHC) in guppies (Poecilia reticulata and P. obscura) and swamp guppies (Micropoecilia picta). Sub-functionalisation of MHC alleles into 'supertypes' explains how polymorphisms persist during rapid host-parasite co-evolution. Simulations show the maintenance of supertypes as balanced polymorphisms, consistent with Red Queen dynamics, whereas alleles within supertypes are subject to positive selection in a Red Queen arms race. Building on the divergent allele advantage hypothesis, we show that functional aspects of allelic diversity help to elucidate the evolution of polymorphic genes involved in Red Queen co-evolution.
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Affiliation(s)
- Jackie Lighten
- School of Environmental Sciences, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK.
| | - Alexander S T Papadopulos
- Molecular Ecology and Fisheries Genetics Laboratory, Environment Centre Wales, School of Biological Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Ryan S Mohammed
- Department of Life Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago
| | - Ben J Ward
- Earlham Institute, Norwich Research Park Innovation Centre, Colney Lane, Norwich, NR4 7UZ, UK
| | - Ian G Paterson
- Marine Gene Probe Laboratory, Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS, Canada, B3H 4R2
| | - Lyndsey Baillie
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Ian R Bradbury
- Marine Gene Probe Laboratory, Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS, Canada, B3H 4R2.,Science Branch, Department of Fisheries and Oceans Canada, 80 East White Hills Road, St. John's, NL, Canada, A1C 5X1
| | - Andrew P Hendry
- McGill University, 859 Sherbrooke Street West, Montreal, QC, Canada, H3A 0C4.,Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, QC, Canada, H3A 0C4
| | - Paul Bentzen
- Marine Gene Probe Laboratory, Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS, Canada, B3H 4R2
| | - Cock van Oosterhout
- School of Environmental Sciences, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK.
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Desvars-Larrive A, Pascal M, Gasqui P, Cosson JF, Benoît E, Lattard V, Crespin L, Lorvelec O, Pisanu B, Teynié A, Vayssier-Taussat M, Bonnet S, Marianneau P, Lacôte S, Bourhy P, Berny P, Pavio N, Le Poder S, Gilot-Fromont E, Jourdain E, Hammed A, Fourel I, Chikh F, Vourc’h G. Population genetics, community of parasites, and resistance to rodenticides in an urban brown rat (Rattus norvegicus) population. PLoS One 2017; 12:e0184015. [PMID: 28886097 PMCID: PMC5590879 DOI: 10.1371/journal.pone.0184015] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 08/16/2017] [Indexed: 11/18/2022] Open
Abstract
Brown rats are one of the most widespread urban species worldwide. Despite the nuisances they induce and their potential role as a zoonotic reservoir, knowledge on urban rat populations remains scarce. The main purpose of this study was to characterize an urban brown rat population from Chanteraines park (Hauts-de-Seine, France), with regards to haematology, population genetics, immunogenic diversity, resistance to anticoagulant rodenticides, and community of parasites. Haematological parameters were measured. Population genetics was investigated using 13 unlinked microsatellite loci. Immunogenic diversity was assessed for Mhc-Drb. Frequency of the Y139F mutation (conferring resistance to rodenticides) and two linked microsatellites were studied, concurrently with the presence of anticoagulant residues in the liver. Combination of microscopy and molecular methods were used to investigate the occurrence of 25 parasites. Statistical approaches were used to explore multiple parasite relationships and model parasite occurrence. Eighty-six rats were caught. The first haematological data for a wild urban R. norvegicus population was reported. Genetic results suggested high genetic diversity and connectivity between Chanteraines rats and surrounding population(s). We found a high prevalence (55.8%) of the mutation Y139F and presence of rodenticide residues in 47.7% of the sampled individuals. The parasite species richness was high (16). Seven potential zoonotic pathogens were identified, together with a surprisingly high diversity of Leptospira species (4). Chanteraines rat population is not closed, allowing gene flow and making eradication programs challenging, particularly because rodenticide resistance is highly prevalent. Parasitological results showed that co-infection is more a rule than an exception. Furthermore, the presence of several potential zoonotic pathogens, of which four Leptospira species, in this urban rat population raised its role in the maintenance and spread of these pathogens. Our findings should stimulate future discussions about the development of a long-term rat-control management program in Chanteraines urban park.
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Affiliation(s)
- Amélie Desvars-Larrive
- Conservation Medicine, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Michel Pascal
- Joint Research Unit (JRU) Écologie et Santé des Écosystèmes (ESE), Institut National de la Recherche Agronomique, INRA, Agrocampus Ouest, Rennes, France
| | - Patrick Gasqui
- Joint Research Unit (JRU) Epidémiologie des Maladies Animales et Zoonotiques (EPIA), Institut National de la Recherche Agronomique, INRA, VetAgro Sup, Saint-Genès Champanelle, France
| | - Jean-François Cosson
- Joint Research Unit (JRU) Biologie Moléculaire et Immunologie Parasitaire (BIPAR), Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), Institut National de la Recherche Agronomique, INRA, Ecole Nationale Vétérinaire d'Alfort (ENVA), Maisons-Alfort, France
- Joint Research Unit (JRU) Centre de Biologie pour la Gestion des Populations (CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Institut National de la Recherche Agronomique, INRA, Institut de Recherche pour le Développement (IRD), SupAgro Montpellier, France
| | - Etienne Benoît
- Contract-based Research Unit (CBRU) Rongeurs Sauvages–Risques Sanitaires et Gestion des Populations (RS2GP), VetAgro Sup, Institut National de la Recherche Agronomique, INRA, Lyon University, Marcy-L’Etoile, France
| | - Virginie Lattard
- Contract-based Research Unit (CBRU) Rongeurs Sauvages–Risques Sanitaires et Gestion des Populations (RS2GP), VetAgro Sup, Institut National de la Recherche Agronomique, INRA, Lyon University, Marcy-L’Etoile, France
| | - Laurent Crespin
- Joint Research Unit (JRU) Epidémiologie des Maladies Animales et Zoonotiques (EPIA), Institut National de la Recherche Agronomique, INRA, VetAgro Sup, Saint-Genès Champanelle, France
| | - Olivier Lorvelec
- Joint Research Unit (JRU) Écologie et Santé des Écosystèmes (ESE), Institut National de la Recherche Agronomique, INRA, Agrocampus Ouest, Rennes, France
| | - Benoît Pisanu
- Unité Mixte de Services (UMS) 2006 Patrimoine Naturel, Agence Française pour la Biodiversité (AFB), Muséum National d'Histoire Naturelle (MNHN), Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Alexandre Teynié
- Joint Research Unit (JRU) Epidémiologie des Maladies Animales et Zoonotiques (EPIA), Institut National de la Recherche Agronomique, INRA, VetAgro Sup, Saint-Genès Champanelle, France
| | - Muriel Vayssier-Taussat
- Joint Research Unit (JRU) Biologie Moléculaire et Immunologie Parasitaire (BIPAR), Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), Institut National de la Recherche Agronomique, INRA, Ecole Nationale Vétérinaire d'Alfort (ENVA), Maisons-Alfort, France
| | - Sarah Bonnet
- Joint Research Unit (JRU) Biologie Moléculaire et Immunologie Parasitaire (BIPAR), Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), Institut National de la Recherche Agronomique, INRA, Ecole Nationale Vétérinaire d'Alfort (ENVA), Maisons-Alfort, France
| | - Philippe Marianneau
- Virology Unit, Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), Lyon, France
| | - Sandra Lacôte
- Virology Unit, Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), Lyon, France
| | - Pascale Bourhy
- Institut Pasteur, Biology of Spirochetes Unit, National Reference Center and WHO Collaborating Center for Leptospirosis, Paris, France
| | - Philippe Berny
- Contract-based Research Unit (CBRU) Rongeurs Sauvages–Risques Sanitaires et Gestion des Populations (RS2GP), VetAgro Sup, Institut National de la Recherche Agronomique, INRA, Lyon University, Marcy-L’Etoile, France
| | - Nicole Pavio
- Joint Research Unit (JRU) Virology, Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), Institut National de la Recherche Agronomique, INRA, Ecole Nationale Vétérinaire d'Alfort (ENVA), Maisons-Alfort, France
| | - Sophie Le Poder
- Joint Research Unit (JRU) Virology, Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail (ANSES), Institut National de la Recherche Agronomique, INRA, Ecole Nationale Vétérinaire d'Alfort (ENVA), Maisons-Alfort, France
| | - Emmanuelle Gilot-Fromont
- Joint Research Unit (JRU) Laboratoire de Biométrie et Biologie Évolutive (LBBE), Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1, VetAgro Sup, Marcy-L’Etoile, France
| | - Elsa Jourdain
- Joint Research Unit (JRU) Epidémiologie des Maladies Animales et Zoonotiques (EPIA), Institut National de la Recherche Agronomique, INRA, VetAgro Sup, Saint-Genès Champanelle, France
| | - Abdessalem Hammed
- Contract-based Research Unit (CBRU) Rongeurs Sauvages–Risques Sanitaires et Gestion des Populations (RS2GP), VetAgro Sup, Institut National de la Recherche Agronomique, INRA, Lyon University, Marcy-L’Etoile, France
| | - Isabelle Fourel
- Contract-based Research Unit (CBRU) Rongeurs Sauvages–Risques Sanitaires et Gestion des Populations (RS2GP), VetAgro Sup, Institut National de la Recherche Agronomique, INRA, Lyon University, Marcy-L’Etoile, France
| | - Farid Chikh
- Conseil Départemental Hauts-de-Seine, Parc de Chanteraines, Villeneuve-la-Garenne, Paris, France
| | - Gwenaël Vourc’h
- Joint Research Unit (JRU) Epidémiologie des Maladies Animales et Zoonotiques (EPIA), Institut National de la Recherche Agronomique, INRA, VetAgro Sup, Saint-Genès Champanelle, France
- * E-mail:
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No evidence for MHC class II-based non-random mating at the gametic haplotype in Atlantic salmon. Heredity (Edinb) 2017; 118:563-567. [PMID: 28098849 DOI: 10.1038/hdy.2016.129] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/17/2016] [Accepted: 12/05/2016] [Indexed: 11/08/2022] Open
Abstract
Genes of the major histocompatibility complex (MHC) are a likely target of mate choice because of their role in inbreeding avoidance and potential benefits for offspring immunocompetence. Evidence for female choice for complementary MHC alleles among competing males exists both for the pre- and the postmating stages. However, it remains unclear whether the latter may involve non-random fusion of gametes depending on gametic haplotypes resulting in transmission ratio distortion or non-random sequence divergence among fused gametes. We tested whether non-random gametic fusion of MHC-II haplotypes occurs in Atlantic salmon Salmo salar. We performed in vitro fertilizations that excluded interindividual sperm competition using a split family design with large clutch sample sizes to test for a possible role of the gametic haplotype in mate choice. We sequenced two MHC-II loci in 50 embryos per clutch to assess allelic frequencies and sequence divergence. We found no evidence for transmission ratio distortion at two linked MHC-II loci, nor for non-random gamete fusion with respect to MHC-II alleles. Our findings suggest that the gametic MHC-II haplotypes play no role in gamete association in Atlantic salmon and that earlier findings of MHC-based mate choice most likely reflect choice among diploid genotypes. We discuss possible explanations for these findings and how they differ from findings in mammals.
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27
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Garamszegi LZ. A simple statistical guide for the analysis of behaviour when data are constrained due to practical or ethical reasons. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2015.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Ferrandiz-Rovira M, Allainé D, Callait-Cardinal MP, Cohas A. Mate choice for neutral and MHC genetic characteristics in Alpine marmots: different targets in different contexts? Ecol Evol 2016; 6:4243-57. [PMID: 27386072 PMCID: PMC4930977 DOI: 10.1002/ece3.2189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/11/2016] [Accepted: 04/26/2016] [Indexed: 01/16/2023] Open
Abstract
Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra‐pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal.
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Affiliation(s)
- Mariona Ferrandiz-Rovira
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR 5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France; Université of Lyon VetAgro Sup Campus Vet F-69280 Marcy-L'Étoile France; CREAF Cerdanyola del Vallès 08193 Catalonia Spain; Univ Autònoma de Barcelona Cerdanyola del Vallès 08193 Catalonia Spain
| | - Dominique Allainé
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France
| | - Marie-Pierre Callait-Cardinal
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR 5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France; Université of Lyon VetAgro Sup Campus Vet F-69280 Marcy-L'Étoile France
| | - Aurélie Cohas
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France
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Seifertová M, Jarkovský J, Šimková A. Does the parasite-mediated selection drive the MHC class IIB diversity in wild populations of European chub (Squalius cephalus)? Parasitol Res 2015; 115:1401-15. [PMID: 26693717 DOI: 10.1007/s00436-015-4874-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 12/07/2015] [Indexed: 11/29/2022]
Abstract
The genes of major histocompatibility complex (MHC) provide an excellent opportunity to study host-parasite relationships because they are expected to evolve in response to parasites and variation in parasite communities. In this study, we investigated the potential role of parasite-mediated selection acting on MHC class IIB (DAB) genes in European chub (Squalius cephalus) natural populations. We found significant differences between populations in metazoan parasites, neutral and adaptive genetic diversities. The analyses based on pairwise data revealed that populations with dissimilar MHC allelic profiles were geographically distant populations with significantly different diversity in microsatellites and a dissimilar composition of parasite communities. The results from the generalized estimating equations method (GEE) on the level of individuals revealed that metazoan parasite load in European chub was influenced by the diversity of DAB alleles as well as by the diversity of neutral genetic markers and host traits reflecting condition and immunocompetence. The multivariate co-inertia analysis showed specific associations between DAB alleles and parasite species. DAB1-like alleles were more involved in associations with ectoparasites, while DAB3-like alleles were positively associated with endoparasites which could suggest potential differences between DAB genes caused by different selection pressure. Our study revealed that parasite-mediated selection is not the only variable affecting MHC diversity in European chub; however, we strongly support the role of neutral processes as the main driver of DAB diversity across populations. In addition, our study contributes to the understanding of the evolution of MHC genes in wild living fish.
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Affiliation(s)
- Mária Seifertová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 61137, Brno, Czech Republic.
| | - Jiří Jarkovský
- Institute of Biostatistics and Analyses, Faculty of Medicine and Faculty of Science, Masaryk University, Kamenice 126/3, 625 00, Brno, Czech Republic
| | - Andrea Šimková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 61137, Brno, Czech Republic
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Talbot B, Garant D, Rioux Paquette S, Mainguy J, Pelletier F. Genetic structure and diversity among rabid and nonrabid raccoons. ECOSCIENCE 2015. [DOI: 10.2980/20-4-3633] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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Characterization of MHC class II genes in the critically endangered European eel (Anguilla anguilla). CONSERV GENET RESOUR 2015. [DOI: 10.1007/s12686-015-0501-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abts KC, Ivy JA, DeWoody JA. Immunomics of the koala (Phascolarctos cinereus). Immunogenetics 2015; 67:305-21. [PMID: 25761531 DOI: 10.1007/s00251-015-0833-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 02/19/2015] [Indexed: 12/20/2022]
Abstract
The study of the koala transcriptome has the potential to advance our understanding of its immunome--immunological reaction of a given host to foreign antigens--and to help combat infectious diseases (e.g., chlamydiosis) that impede ongoing conservation efforts. We used Illumina sequencing of cDNA to characterize genes expressed in two different koala tissues of immunological importance, blood and spleen. We generated nearly 600 million raw sequence reads, and about 285 million of these were subsequently assembled and condensed into ~70,000 subcomponents that represent putative transcripts. We annotated ~16% of these subcomponents and identified those related to infection and the immune response, including Toll-like receptors (TLRs), RIG-I-like receptors (RLRs), major histocompatibility complex (MHC) genes, and koala retrovirus (KoRV). Using phylogenetic analyses, we identified 29 koala genes in these target categories and report their concordance with currently accepted gene groups. By mapping multiple sequencing reads to transcripts, we identified 56 putative SNPs in genes of interest. The distribution of these SNPs indicates that MHC genes (34 SNPs) are more diverse than KoRV (12 SNPs), TLRs (8 SNPs), or RLRs (2 SNPs). Our sequence data also indicate that KoRV sequences are highly expressed in the transcriptome. Our efforts have produced full-length sequences for potentially important immune genes in koala, which should serve as targets for future investigations that aim to conserve koala populations.
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Affiliation(s)
- Kendra C Abts
- Department of Forestry and Natural Resources, Purdue University, 195 Marsteller St, West Lafayette, IN, 47907, USA,
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Pechouskova E, Dammhahn M, Brameier M, Fichtel C, Kappeler PM, Huchard E. MHC class II variation in a rare and ecological specialist mouse lemur reveals lower allelic richness and contrasting selection patterns compared to a generalist and widespread sympatric congener. Immunogenetics 2015; 67:229-45. [PMID: 25687337 PMCID: PMC4357647 DOI: 10.1007/s00251-015-0827-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/30/2015] [Indexed: 11/20/2022]
Abstract
The polymorphism of immunogenes of the major histocompatibility complex (MHC) is thought to influence the functional plasticity of immune responses and, consequently, the fitness of populations facing heterogeneous pathogenic pressures. Here, we evaluated MHC variation (allelic richness and divergence) and patterns of selection acting on the two highly polymorphic MHC class II loci (DRB and DQB) in the endangered primate Madame Berthe’s mouse lemur (Microcebus berthae). Using 454 pyrosequencing, we examined MHC variation in a total of 100 individuals sampled over 9 years in Kirindy Forest, Western Madagascar, and compared our findings with data obtained previously for its sympatric congener, the grey mouse lemur (Microcebus murinus). These species exhibit a contrasting ecology and demography that were expected to affect MHC variation and molecular signatures of selection. We found a lower allelic richness concordant with its low population density, but a similar level of allelic divergence and signals of historical selection in the rare feeding specialist M. berthae compared to the widespread generalist M. murinus. These findings suggest that demographic factors may exert a stronger influence than pathogen-driven selection on current levels of allelic richness in M. berthae. Despite a high sequence similarity between the two congeners, contrasting selection patterns detected at DQB suggest its potential functional divergence. This study represents a first step toward unravelling factors influencing the adaptive divergence of MHC genes between closely related but ecologically differentiated sympatric lemurs and opens new questions regarding potential functional discrepancy that would explain contrasting selection patterns detected at DQB.
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Affiliation(s)
- Eva Pechouskova
- Behavioral Ecology and Sociobiology Unit, German Primate Center, Kellnerweg 4, Göttingen, Germany,
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Pilosof S, Fortuna MA, Cosson JF, Galan M, Kittipong C, Ribas A, Segal E, Krasnov BR, Morand S, Bascompte J. Host-parasite network structure is associated with community-level immunogenetic diversity. Nat Commun 2014; 5:5172. [PMID: 25312328 DOI: 10.1038/ncomms6172] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Accepted: 09/08/2014] [Indexed: 12/13/2022] Open
Abstract
Genes of the major histocompatibility complex (MHC) encode proteins that recognize foreign antigens and are thus crucial for immune response. In a population of a single host species, parasite-mediated selection drives MHC allelic diversity. However, in a community-wide context, species interactions may modulate selection regimes because the prevalence of a given parasite in a given host may depend on its prevalence in other hosts. By combining network analysis with immunogenetics, we show that host species infected by similar parasites harbour similar alleles with similar frequencies. We further show, using a Bayesian approach, that the probability of mutual occurrence of a functional allele and a parasite in a given host individual is nonrandom and depends on other host-parasite interactions, driving co-evolution within subgroups of parasite species and functional alleles. Therefore, indirect effects among hosts and parasites can shape host MHC diversity, scaling it from the population to the community level.
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Affiliation(s)
- Shai Pilosof
- Mitrani Department of Desert Ecology and Albert Katz International School for Desert Studies, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
| | - Miguel A Fortuna
- Integrative Ecology Group, Estación Biológica de Doñana (EBD-CSIC), Seville 41092, Spain
| | - Jean-François Cosson
- INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro), Campus International de Baillarguet, CS 30016, 34988 Montferrier-sur-Lez cedex, France
| | - Maxime Galan
- INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro), Campus International de Baillarguet, CS 30016, 34988 Montferrier-sur-Lez cedex, France
| | - Chaisiri Kittipong
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Alexis Ribas
- Biodiversity Research Group, Faculty of Science, Udon Thani Rajabhat University, Udon Thani 41000, Thailand
| | - Eran Segal
- Department of Computer Science and Applied Mathematics, Weizmann Institute, Rehovot, 76100, Israel
| | - Boris R Krasnov
- Mitrani Department of Desert Ecology and Albert Katz International School for Desert Studies, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
| | - Serge Morand
- 1] Centre National de la Recherche Scientifique-Institut des Sciences de l'Évolution, Université Montpellier 2, Montpellier 34095, France [2] Centre de coopération International en Recherche Agronomique pour le Développement, Animal et Gestion Intégrée des Risques, Campus de Baillarguet, F-34093 Montpellier Cedex 5, France [3] Centre d'Infectiologie Christophe Mérieux du Laos, PO Box 3888, Samsenthai Road, Vientiane, Lao PDR
| | - Jordi Bascompte
- Integrative Ecology Group, Estación Biológica de Doñana (EBD-CSIC), Seville 41092, Spain
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Hablützel PI, Vanhove MPM, Grégoir AF, Hellemans B, Volckaert FAM, Raeymaekers JAM. Intermediate number of major histocompatibility complex class IIB
length variants relates to enlarged perivisceral fat deposits in the blunt-head cichlid Tropheus moorii. J Evol Biol 2014; 27:2177-90. [DOI: 10.1111/jeb.12467] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 07/18/2014] [Accepted: 07/27/2014] [Indexed: 01/31/2023]
Affiliation(s)
- P. I. Hablützel
- Laboratory of Biodiversity and Evolutionary Genomics; University of Leuven; Leuven Belgium
| | - M. P. M. Vanhove
- Laboratory of Biodiversity and Evolutionary Genomics; University of Leuven; Leuven Belgium
- Department of Botany and Zoology; Faculty of Science; Masaryk University; Brno Czech Republic
- Biology Department; Royal Museum for Central Africa; Tervuren Belgium
- Institute of Marine Biological Resources and Inland Waters; Hellenic Centre for Marine Research; Anavyssos Greece
| | - A. F. Grégoir
- Laboratory of Aquatic Ecology, Evolution and Conservation; University of Leuven; Leuven Belgium
| | - B. Hellemans
- Laboratory of Biodiversity and Evolutionary Genomics; University of Leuven; Leuven Belgium
| | - F. A. M. Volckaert
- Laboratory of Biodiversity and Evolutionary Genomics; University of Leuven; Leuven Belgium
| | - J. A. M. Raeymaekers
- Laboratory of Biodiversity and Evolutionary Genomics; University of Leuven; Leuven Belgium
- Zoological Institute; University of Basel; Basel Switzerland
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Spatial variation and low diversity in the major histocompatibility complex in walrus (Odobenus rosmarus). Polar Biol 2014. [DOI: 10.1007/s00300-014-1450-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Müller N, Ostner J, Schülke O, Walter L. Towards the non-invasive assessment of MHC genotype in wild primates: analysis of wild Assamese macaque MHC-DRB from fecal samples. Am J Primatol 2013; 76:230-8. [PMID: 24151109 DOI: 10.1002/ajp.22225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 09/04/2013] [Accepted: 09/17/2013] [Indexed: 12/11/2022]
Abstract
The major histocompatibility complex (MHC) plays an important role in the immune response and may thus crucially affect an individual's fitness, relevant also for studies on evolutionary ecology and wildlife conservation. Detailed knowledge on the genomic organization, polymorphism and diversity of the MHC has a narrow taxonomic focus though and among macaques is only available for rhesus and long-tailed macaques-the species most commonly kept for biomedical research. The lack of data on wild populations is largely due to the difficulty of obtaining blood or tissue samples necessary for genotyping approaches. Here, we aimed at analyzing MHC-DRB from non-invasively collected fecal samples in wild Assamese macaques (Macaca assamensis), utilizing the MHC-DRB-STR (D6S2878) microsatellite marker. Due to the fecal DNA source incomplete genotypes occurred, which may be improved in the future by method refinement. We detected 28 distinct DRB-STR lengths in 43 individuals with individual genotypes containing 1-9 MHC-DRB-STRs and defined four haplotypes segregating between families in Mendelian fashion. Our results indicate that variability and diversity of MHC-DRB in Assamese macaques is comparable to that of other macaque species and importantly, that fecal samples can be used for non-invasive analysis of MHC genes after refinement of the applied methods, opening a number of opportunities for MHC research on natural populations.
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Affiliation(s)
- Nadine Müller
- Social Evolution in Primates Group, Courant Research Center Evolution of Social Behavior, Georg-August University Göttingen, Göttingen, Germany
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Lenz TL, Mueller B, Trillmich F, Wolf JBW. Divergent allele advantage at MHC-DRB through direct and maternal genotypic effects and its consequences for allele pool composition and mating. Proc Biol Sci 2013; 280:20130714. [PMID: 23677346 DOI: 10.1098/rspb.2013.0714] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It is still debated whether main individual fitness differences in natural populations can be attributed to genome-wide effects or to particular loci of outstanding functional importance such as the major histocompatibility complex (MHC). In a long-term monitoring project on Galápagos sea lions (Zalophus wollebaeki), we collected comprehensive fitness and mating data for a total of 506 individuals. Controlling for genome-wide inbreeding, we find strong associations between the MHC locus and nearly all fitness traits. The effect was mainly attributable to MHC sequence divergence and could be decomposed into contributions of own and maternal genotypes. In consequence, the population seems to have evolved a pool of highly divergent alleles conveying near-optimal MHC divergence even by random mating. Our results demonstrate that a single locus can significantly contribute to fitness in the wild and provide conclusive evidence for the 'divergent allele advantage' hypothesis, a special form of balancing selection with interesting evolutionary implications.
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Affiliation(s)
- Tobias L Lenz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
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Stiebens VA, Merino SE, Chain FJJ, Eizaguirre C. Evolution of MHC class I genes in the endangered loggerhead sea turtle (Caretta caretta) revealed by 454 amplicon sequencing. BMC Evol Biol 2013; 13:95. [PMID: 23627726 PMCID: PMC3655109 DOI: 10.1186/1471-2148-13-95] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 04/17/2013] [Indexed: 11/17/2022] Open
Abstract
Background In evolutionary and conservation biology, parasitism is often highlighted as a major selective pressure. To fight against parasites and pathogens, genetic diversity of the immune genes of the major histocompatibility complex (MHC) are particularly important. However, the extensive degree of polymorphism observed in these genes makes it difficult to conduct thorough population screenings. Methods We utilized a genotyping protocol that uses 454 amplicon sequencing to characterize the MHC class I in the endangered loggerhead sea turtle (Caretta caretta) and to investigate their evolution at multiple relevant levels of organization. Results MHC class I genes revealed signatures of trans-species polymorphism across several reptile species. In the studied loggerhead turtle individuals, it results in the maintenance of two ancient allelic lineages. We also found that individuals carrying an intermediate number of MHC class I alleles are larger than those with either a low or high number of alleles. Conclusions Multiple modes of evolution seem to maintain MHC diversity in the loggerhead turtles, with relatively high polymorphism for an endangered species.
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Affiliation(s)
- Victor A Stiebens
- Department of Evolutionary Ecology of Marine Fishes, GEOMAR
- Helmholtz Center for Ocean Research, Kiel, 24105, Germany
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Axtner J, Sommer S. The functional importance of sequence versus expression variability of MHC alleles in parasite resistance. Genetica 2012. [PMID: 23180005 DOI: 10.1007/s10709-012-9689-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Understanding selection processes driving the pronounced allelic polymorphism of the major histocompatibility complex (MHC) genes and its functional associations to parasite load have been the focus of many recent wildlife studies. Two main selection scenarios are currently debated which explain the susceptibility or resistance to parasite infections either by the effects of (1) specific MHC alleles which are selected frequency-dependent in space and time or (2) a heterozygote or divergent allele advantage. So far, most studies have focused only on structural variance in co-evolutionary processes although this might not be the only trait subject to natural selection. In the present study, we analysed structural variance stretching from exon1 through exon3 of MHC class II DRB genes as well as genotypic expression variance in relation to the gastrointestinal helminth prevalence and infection intensity in wild yellow-necked mice (Apodemus flavicollis). We found support for the functional importance of specific alleles both on the sequence and expression level. By resampling a previously investigated study population we identified specific MHC alleles affected by temporal shifts in parasite pressure and recorded associated changes in allele frequencies. The allele Apfl-DRB*23 was associated with resistance to infections by the oxyurid nematode Syphacia stroma and at the same time with susceptibility to cestode infection intensity. In line with our expectation, MHC mRNA transcript levels tended to be higher in cestode-infected animals carrying the allele Apfl-DRB*23. However, no support for a heterozygote or divergent allele advantage on the sequence or expression level was detected. The individual amino acid distance of genotypes did not explain individual differences in parasite loads and the genetic distance had no effect on MHC genotype expression. For ongoing studies on the functional importance of expression variance in parasite resistance, allele-specific expression data would be preferable.
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Affiliation(s)
- Jan Axtner
- Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 15, 10315, Berlin, Germany.
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41
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Oomen RA, Gillett RM, Kyle CJ. Comparison of 454 pyrosequencing methods for characterizing the major histocompatibility complex of nonmodel species and the advantages of ultra deep coverage. Mol Ecol Resour 2012; 13:103-16. [PMID: 23095905 DOI: 10.1111/1755-0998.12027] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 09/07/2012] [Accepted: 09/11/2012] [Indexed: 12/23/2022]
Abstract
Characterization and population genetic analysis of multilocus genes, such as those found in the major histocompatibility complex (MHC) is challenging in nonmodel vertebrates. The traditional method of extensive cloning and Sanger sequencing is costly and time-intensive and indirect methods of assessment often underestimate total variation. Here, we explored the suitability of 454 pyrosequencing for characterizing multilocus genes for use in population genetic studies. We compared two sample tagging protocols and two bioinformatic procedures for 454 sequencing through characterization of a 185-bp fragment of MHC DRB exon 2 in wolverines (Gulo gulo) and further compared the results with those from cloning and Sanger sequencing. We found 10 putative DRB alleles in the 88 individuals screened with between two and four alleles per individual, suggesting amplification of a duplicated DRB gene. In addition to the putative alleles, all individuals possessed an easily identifiable pseudogene. In our system, sequence variants with a frequency below 6% in an individual sample were usually artefacts. However, we found that sample preparation and data processing procedures can greatly affect variant frequencies in addition to the complexity of the multilocus system. Therefore, we recommend determining a per-amplicon-variant frequency threshold for each unique system. The extremely deep coverage obtained in our study (approximately 5000×) coupled with the semi-quantitative nature of pyrosequencing enabled us to assign all putative alleles to the two DRB loci, which is generally not possible using traditional methods. Our method of obtaining locus-specific MHC genotypes will enhance population genetic analyses and studies on disease susceptibility in nonmodel wildlife species.
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Affiliation(s)
- Rebekah A Oomen
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada.
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Reichard M, Spence R, Bryjová A, Bryja J, Smith C. Female rose bitterling prefer MHC-dissimilar males: experimental evidence. PLoS One 2012; 7:e40780. [PMID: 22815816 PMCID: PMC3399850 DOI: 10.1371/journal.pone.0040780] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 06/13/2012] [Indexed: 11/19/2022] Open
Abstract
The role of genetic benefits in female mate choice remains a controversial aspect of sexual selection theory. In contrast to "good allele" models of sexual selection, "compatible allele" models of mate choice predict that females prefer mates with alleles complementary to their own rather than conferring additive effects. While correlative results suggest complementary genetic effects to be plausible, direct experimental evidence is scarce. A previous study on the Chinese rose bitterling (Rhodeus ocellatus) demonstrated a positive correlation between female mate choice, offspring growth and survival, and the functional dissimilarity between the Major Histocompatibility Complex (MHC) alleles of males and females. Here we directly tested whether females used cues associated with MHC genes to select genetically compatible males in an experimental framework. By sequentially pairing females with MHC similar and dissimilar males, based on a priori known MHC profiles, we showed that females discriminated between similar and dissimilar males and deposited significantly more eggs with MHC dissimilar males. Notably, the degree of dissimilarity was an important factor for female decision to mate, possibly indicating a potential threshold value of dissimilarity for decision making, or of an indirect effect of the MHC.
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Affiliation(s)
- Martin Reichard
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
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43
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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: 39] [Impact Index Per Article: 3.3] [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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44
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Axtner J, Sommer S. Heligmosomoides polygyrus infection is associated with lower MHC class II gene expression in Apodemus flavicollis: indication for immune suppression? INFECTION GENETICS AND EVOLUTION 2011; 11:2063-71. [PMID: 21983561 DOI: 10.1016/j.meegid.2011.09.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 09/22/2011] [Accepted: 09/22/2011] [Indexed: 01/16/2023]
Abstract
Due to their key role in recognizing foreign antigens and triggering the subsequent immune response the genes of the major histocompatibility complex (MHC) provide a potential target for parasites to attack in order to evade detection and expulsion from the host. A diminished MHC gene expression results in less activated T cells and might serve as a gateway for pathogens and parasites. Some parasites are suspected to be immune suppressors and promote co-infections of other parasites even in other parts of the body. In our study we found indications that the gut dwelling nematode Heligmosomoides polygyrus might exert a systemic immunosuppressive effect in yellow-necked mice (Apodemus flavicollis). The amount of hepatic MHC class II DRB gene RNA transcripts in infected mice was negatively associated with infection intensity with H. polygyrus. The hepatic expression of immunosuppressive cytokines, such as transforming growth factor β and interleukin 10 was not associated with H. polygyrus infection. We did not find direct positive associations of H. polygyrus with other helminth species. But the prevalence and infection intensity of the nematodes Syphacia stroma and Trichuris muris were higher in multiple infected individuals. Furthermore, our data indicated antagonistic effects in the helminth community of A. flavicollis as cestode infection correlated negatively with H. polygyrus and helminth species richness. Our study shows that expression analyses of immune relevant genes can also be performed in wildlife, opening new aspects and possibilities for future ecological and evolutionary research.
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Affiliation(s)
- Jan Axtner
- Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str 15, 10315 Berlin, Germany
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Bordes F, Morand S. The impact of multiple infections on wild animal hosts: a review. Infect Ecol Epidemiol 2011; 1:IEE-1-7346. [PMID: 22957114 PMCID: PMC3426331 DOI: 10.3402/iee.v1i0.7346] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 08/11/2011] [Accepted: 08/25/2011] [Indexed: 12/23/2022] Open
Abstract
Field parasitological studies consistently demonstrate the reality of polyparasitism in natural systems. However, only recently, studies from ecological and evolutionary fields have emphasised a broad spectrum of potential multiple infections-related impacts. The main goal of our review is to reunify the different approaches on the impacts of polyparasitism, not only from laboratory or human medical studies but also from field or theoretical studies. We put forward that ecological and epidemiological determinants to explain the level of polyparasitism, which regularly affects not only host body condition, survival or reproduction but also host metabolism, genetics or immune investment. Despite inherent limitations of all these studies, multiple infections should be considered more systematically in wildlife to better appreciate the importance of parasite diversity in wildlife, cumulative effects of parasitism on the ecology and evolution of their hosts.
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Affiliation(s)
- Frédéric Bordes
- Institut des Sciences de l'Evolution, CNRS-UM2, CC65, Université de Montpellier, Montpellier, France
| | - Serge Morand
- Institut des Sciences de l'Evolution, CNRS-UM2, CC65, Université de Montpellier, Montpellier, France
- UR22 AGIRs, CIRAD, Campus International de Baillarguet, 34398, Montpellier, France
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Depleted genetic variation of the European ground squirrel in Central Europe in both microsatellites and the major histocompatibility complex gene: implications for conservation. CONSERV GENET 2011. [DOI: 10.1007/s10592-011-0213-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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47
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Lenz TL. Computational prediction of MHC II-antigen binding supports divergent allele advantage and explains trans-species polymorphism. Evolution 2011; 65:2380-90. [PMID: 21790583 DOI: 10.1111/j.1558-5646.2011.01288.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The major histocompatibility complex (MHC), coding for antigen presenting molecules of the adaptive immune system, represents one of the most polymorphic regions in the vertebrate genome. The exceptional polymorphism, which is potentially maintained by balancing selection under host-parasite coevolution, comprises excessive sequence divergence among alleles as well as ancient allelic lineages that predate species divergence (trans-species polymorphism). Here, the mechanisms that are proposed to maintain such sequence divergence and ancient lineages are investigated. Established computational antigen-binding prediction algorithms, which are based on empirical databases, are employed to determine the overlap in bound antigens among individual MHC class IIB alleles. The results show that genetically more divergent allele pairs experience less overlap and thus present a broader range of potential antigens. These findings support the divergent allele advantage hypothesis and furthermore suggest an evolutionary advantage explaining the maintenance of divergent allelic lineages, that is, trans-species polymorphism. In addressing a quantitative rather than qualitative aspect of MHC alleles, these insights highlight a new direction for future research on MHC evolution.
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Affiliation(s)
- Tobias L Lenz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306 Plön, Germany.
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48
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Griggio M, Biard C, Penn DJ, Hoi H. Female house sparrows "count on" male genes: experimental evidence for MHC-dependent mate preference in birds. BMC Evol Biol 2011; 11:44. [PMID: 21320306 PMCID: PMC3044665 DOI: 10.1186/1471-2148-11-44] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 02/14/2011] [Indexed: 01/08/2023] Open
Abstract
Background Females can potentially assess the quality of potential mates using their secondary sexual traits, and obtain "good genes" that increase offspring fitness. Another potential indirect benefit from mating preferences is genetic compatibility, which does not require extravagant or viability indicator traits. Several studies with mammals and fish indicate that the genes of the major histocompatibility complex (MHC) influence olfactory cues and mating preferences, and such preferences confer genetic benefits to offspring. We investigated whether individual MHC diversity (class I) influences mating preferences in house sparrows (Passer domesticus). Results Overall, we found no evidence that females preferred males with high individual MHC diversity. Yet, when we considered individual MHC allelic diversity of the females, we found that females with a low number of alleles were most attracted to males carrying a high number of MHC alleles, which might reflect a mating-up preference by allele counting. Conclusions This is the first experimental evidence for MHC-dependent mating preferences in an avian species to our knowledge. Our findings raise questions about the underlying mechanisms through which birds discriminate individual MHC diversity among conspecifics, and they suggest a novel mechanism through which mating preferences might promote the evolution of MHC polymorphisms and generate positive selection for duplicated MHC loci.
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Affiliation(s)
- Matteo Griggio
- Konrad Lorenz Institute for Ethology, Austrian Academy of Sciences, Austria.
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Eizaguirre C, Lenz TL. Major histocompatibility complex polymorphism: dynamics and consequences of parasite-mediated local adaptation in fishes. JOURNAL OF FISH BIOLOGY 2010; 77:2023-2047. [PMID: 21133915 DOI: 10.1111/j.1095-8649.2010.02819.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Parasitism is a common form of life and represents a strong selective pressure for host organisms. In response to this evolutionary pressure, vertebrates have developed genetically coded defences such as the major histocompatibility complex (MHC). Mechanisms of parasite-mediated selection not only maintain outstanding polymorphism in these genes but have also been proposed to further promote host population divergence and ultimately speciation because it can drive evolution of local adaptation in which MHC genes play a crucial role. This review first highlights the dynamics and complexity of parasite-mediated selection in natural systems, which not only depends on dominating parasite strategies and on the taxonomic diversity of the parasite community but also includes the differences in parasite communities between habitats and niches, creating divergent selection on locally adapted populations. Then the different ways in which MHC genes potentially allow vertebrates to respond to these dynamics and to adapt locally are outlined. Finally, it is proposed that varying selection strength in time and space may lead to variation in the strength of precopulatory reproductive isolation which has evolved to maintain local adaptation.
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Affiliation(s)
- C Eizaguirre
- Leibniz Institute for Marine Sciences (IFM GEOMAR), Department of Evolutionary Ecology of Marine Fishes, Düsternbrooker Weg 20, 24105, Kiel, Germany.
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