1
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Ferreira D, San‐Jose LM, Roulin A, Gaigher A, Fumagalli L. Limited associations between MHC diversity and reproductive success in a bird species with biparental care. Ecol Evol 2024; 14:e10950. [PMID: 38384825 PMCID: PMC10879840 DOI: 10.1002/ece3.10950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 12/13/2023] [Indexed: 02/23/2024] Open
Abstract
The selective pressure from pathogens on individuals can have direct consequences on reproduction. Genes from the major histocompatibility complex (MHC) are central to the vertebrate adaptive immune system and pathogen resistance. In species with biparental care, each sex has distinct reproductive roles and levels of investment, and due to a trade-off with immunity, one can expect different selective regimes acting upon the MHC of each parent. Here, we addressed whether couples combine each other's variation at MHC loci to increase their breeding success. Specifically, we used a 23-year dataset from a barn owl population (Tyto alba) to understand how MHC class Iα and IIβ functional divergence and supertypes of each parent were associated with clutch size and fledging success. We did not detect associations between MHC diversity and supertypes with the clutch size or with the fledging success. In addition, to understand the relative contribution from the MHC of the genetic parents and the social parents, we analyzed the fledging success using only a cross-fostered dataset. We found several associations of weak-to-moderate effect sizes between the father's MHC and fledging success: (i) lower MHC-Iα divergence in the genetic father increases fledging success, which might improve paternal care during incubation, and (ii) one and two MHC-IIβ DAB2 supertypes in the social father decrease and increase, respectively, fledging success, which may affect the paternal care after hatching. Furthermore, fledging success increased when both parents did not carry MHC-IIβ DAB1 supertype 2, which could suggest conditional effects of this supertype. Although our study relied on a substantial dataset, we showed that the associations between MHC diversity and reproductive success remain scarce and of complex interpretation in the barn owl. Moreover, our results highlighted the need to incorporate more than one proxy of reproductive success and several MHC classes to capture more complex associations.
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Affiliation(s)
- Diana Ferreira
- Laboratory for Conservation Biology, Department of Ecology and Evolution, BiophoreUniversity of LausanneLausanneSwitzerland
| | - Luis M. San‐Jose
- Laboratoire Évolution and Diversité Biologique, UMR 5174, CNRSUniversité Toulouse III Paul Sabatier, IRDToulouseFrance
| | - Alexandre Roulin
- Department of Ecology and Evolution, BiophoreUniversity of LausanneLausanneSwitzerland
| | - Arnaud Gaigher
- CIBIO‐InBIO, Research Center in Biodiversity and Genetic ResourcesUniversity of PortoVairãoPortugal
- Research Unit for Evolutionary Immunogenomics, Department of BiologyUniversity of HamburgHamburgGermany
| | - Luca Fumagalli
- Laboratory for Conservation Biology, Department of Ecology and Evolution, BiophoreUniversity of LausanneLausanneSwitzerland
- Swiss Human Institute of Forensic Taphonomy, University Centre of Legal Medicine Lausanne‐GenevaLausanne University Hospital and University of LausanneLausanneSwitzerland
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2
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Pikus E, Dunn PO, Minias P. High MHC diversity confers no advantage for phenotypic quality and reproductive performance in a wild bird. J Anim Ecol 2022; 91:1707-1718. [PMID: 35521665 PMCID: PMC9542035 DOI: 10.1111/1365-2656.13737] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/24/2022] [Indexed: 11/28/2022]
Abstract
1. Genes of the major histocompatibility complex (MHC) encode antigen binding molecules and are an integral part of the acquired immune response of vertebrates. In general, high individual MHC diversity is expected to increase fitness by broadening the spectrum of pathogens recognized by the immune system, in accordance with the heterozygote advantage mechanism. On the other hand, the optimality hypothesis assumes that individuals with optimal (intermediate), rather than maximum diversity of the MHC will achieve the highest fitness because of inherent costs associated with expressing diverse MHC alleles. 2. Here, we tested for associations between individual diversity of the MHC class I and class II genes (binding antigens of intra- and extra-cellular pathogens, respectively) and a range of fitness-related traits (condition, ornament expression and reproduction) in an urban population of the Eurasian coot Fulica atra. 3. Contrary to our expectation, we found that high within-individual allelic diversity of MHC genes (both class I and II) was associated with poorer condition (lower blood haemoglobin concentrations), weaker expression of the putative ornament (smaller frontal shield), later onset of breeding and smaller clutches. An analysis of functional MHC allele clusters (supertypes) provided further support for negative associations of MHC diversity with phenotypic quality and reproductive performance, but most of these relationships could not be explained by the presence of specific maladaptive supertypes. Finally, we found little empirical support for the optimality hypothesis in the Eurasian coot. 4. Our results suggest that the costs of high MHC diversity outweighed any benefits associated with broad MHC repertoire, which could be driven by depauperate pathogen diversity in an urban landscape. To the best of our knowledge, this is one of the first studies providing consistent evidence for negative associations of MHC diversity with a range of fitness-related traits in a natural avian population.
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Affiliation(s)
- Ewa Pikus
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland
| | - Peter O Dunn
- Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-, Milwaukee
| | - Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland
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3
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Fleischer R, Schmid DW, Uddin W, Brändel SD, Rasche A, Corman VM, Drosten C, Tschapka M, Sommer S. Interaction between MHC diversity and constitution, gut microbiota and Astrovirus infections in a neotropical bat. Mol Ecol 2022; 31:3342-3359. [PMID: 35510794 DOI: 10.1111/mec.16491] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/28/2022]
Abstract
Astroviruses (AstVs) infect numerous mammalian species including reservoirs such as bats. Peptides encoded by the genes of the highly polymorphic Major Histocompatibility Complex (MHC) form the first line of host defence against pathogens. Aside from direct involvement in mounting adaptive immune responses, MHC class II genes are hypothesized to regulate gut commensal diversity and shape the production of immune-modulatory substances by microbes, indirectly affecting host susceptibility. Despite initial empirical evidence for the link between host MHC and the microbiota, associations among these factors remain largely unknown. To fill this gap, we examined MHC allelic diversity and constitution, the gut bacterial community and abundance pattern of a wild population of the neotropical bat (Artibeus jamaicensis) challenged by AstV infections. First, we show an age-dependent relationship between the host MHC class II diversity and constitution and the gut microbiota in AstV uninfected bats. Crucially, these associations changed in AstV infected bats. Additionally, we identify changes in abundance of specific bacterial taxa linked to the presence of certain MHC supertypes and AstV infection. We suggest changes in the microbiota to be either a result of AstV infection or the MHC-mediated modulation of microbial communities. The latter could subsequently affect microbe-mediated immunity and resistance against AstV infection. Our results underscore that the reciprocal nature of host immune genetics, gut microbial diversity and pathogen infection requires attention, which is particularly important given its repercussions for disease susceptibility and severity in wild animal populations with a history of zoonotic spillover and frequent human contact.
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Affiliation(s)
- Ramona Fleischer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Dominik Werner Schmid
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Wasim Uddin
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Stefan Dominik Brändel
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.,Smithsonian Tropical Research Institute, Ancon, Panama
| | - Andrea Rasche
- Smithsonian Tropical Research Institute, Ancon, Panama.,Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Free University, Humboldt-University and Berlin Institute of Health, Chariteplatz 1, 10117, Berlin, Germany
| | - Victor M Corman
- Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Free University, Humboldt-University and Berlin Institute of Health, Chariteplatz 1, 10117, Berlin, Germany.,German Centre for Infection Research (DZIF), associated partner Charité, Chariteplatz 1, 10117, Berlin, Germany
| | - Christian Drosten
- Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Free University, Humboldt-University and Berlin Institute of Health, Chariteplatz 1, 10117, Berlin, Germany.,German Centre for Infection Research (DZIF), associated partner Charité, Chariteplatz 1, 10117, Berlin, Germany
| | - Marco Tschapka
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.,Smithsonian Tropical Research Institute, Ancon, Panama
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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4
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Davies CS, Worsley SF, Maher KH, Komdeur J, Burke T, Dugdale HL, Richardson DS. Immunogenetic variation shapes the gut microbiome in a natural vertebrate population. MICROBIOME 2022; 10:41. [PMID: 35256003 PMCID: PMC8903650 DOI: 10.1186/s40168-022-01233-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND The gut microbiome (GM) can influence many biological processes in the host, impacting its health and survival, but the GM can also be influenced by the host's traits. In vertebrates, Major Histocompatibility Complex (MHC) genes play a pivotal role in combatting pathogens and are thought to shape the host's GM. Despite this-and the documented importance of both GM and MHC variation to individual fitness-few studies have investigated the association between the GM and MHC in the wild. RESULTS We characterised MHC class I (MHC-I), MHC class II (MHC-II) and GM variation in individuals within a natural population of the Seychelles warbler (Acrocephalus sechellensis). We determined how the diversity and composition of the GM varied with MHC characteristics, in addition to environmental factors and other host traits. Our results show that the presence of specific MHC alleles, but not MHC diversity, influences both the diversity and composition of the GM in this population. MHC-I alleles, rather than MHC-II alleles, had the greatest impact on the GM. GM diversity was negatively associated with the presence of three MHC-I alleles (Ase-ua3, Ase-ua4, Ase-ua5), and one MHC-II allele (Ase-dab4), while changes in GM composition were associated with the presence of four different MHC-I alleles (Ase-ua1, Ase-ua7, Ase-ua10, Ase-ua11). There were no associations between GM diversity and TLR3 genotype, but GM diversity was positively correlated with genome-wide heterozygosity and varied with host age and field period. CONCLUSIONS These results suggest that components of the host's immune system play a role in shaping the GM of wild animals. Host genotype-specifically MHC-I and to a lesser degree MHC-II variation-can modulate the GM, although whether this occurs directly, or indirectly through effects on host health, is unclear. Importantly, if immune genes can regulate host health through modulation of the microbiome, then it is plausible that the microbiome could also influence selection on immune genes. As such, host-microbiome coevolution may play a role in maintaining functional immunogenetic variation within natural vertebrate populations. Video abstract.
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Affiliation(s)
- Charli S Davies
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norfolk, NR4 7TJ, UK.
- NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.
| | - Sarah F Worsley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norfolk, NR4 7TJ, UK
| | - Kathryn H Maher
- NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Jan Komdeur
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
| | - Terry Burke
- NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Hannah L Dugdale
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
- Faculty of Biological Sciences, School of Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - David S Richardson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norfolk, NR4 7TJ, UK
- Nature Seychelles, Roche Caiman, Mahé, Republic of Seychelles
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5
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Leclaire S, Pineaux M, Blanchard P, White J, Hatch SA. Microbiota composition and diversity of multiple body sites vary according to reproductive performance in a seabird. Mol Ecol 2022; 32:2115-2133. [PMID: 35152516 DOI: 10.1111/mec.16398] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 01/03/2022] [Accepted: 02/07/2022] [Indexed: 11/30/2022]
Abstract
The microbiota is suggested to be a fundamental contributor to host reproduction and survival, but associations between microbiota and fitness are rare, especially for wild animals. Here, we tested the association between microbiota and two proxies of breeding performance in multiple body sites of the black-legged kittiwake, a seabird species. First we found that, in females, nonbreeders (i.e., birds that did not lay eggs) hosted different microbiota composition to that of breeders in neck and flank feathers, in the choanae, in the outer-bill and in the cloacae, but not in preen feathers and tracheae. These differences in microbiota might reflect variations in age or individual quality between breeders and nonbreeders. Second, we found that better female breeders (i.e., with higher body condition, earlier laying date, heavier eggs, larger clutch, and higher hatching success) had lower abundance of several Corynebacteriaceae in cloaca than poorer female breeders, suggesting that these bacteria might be pathogenic. Third, in females, better breeders had different microbiota composition and lower microbiota diversity in feathers, especially in preen feathers. They had also reduced dispersion in microbiota composition across body sites. These results might suggest that good breeding females are able to control their feather microbiota-potentially through preen secretions-more tightly than poor breeding females. We did not find strong evidence for an association between reproductive outcome and microbiota in males. Our results are consistent with the hypothesis that natural variation in the microbiota is associated with differences in host fitness in wild animals, but the causal relationships remain to be investigated.
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Affiliation(s)
- Sarah Leclaire
- Laboratoire Evolution et Diversité Biologique (EDB) UMR5174 Université Toulouse 3 Paul Sabatier CNRS, IRD Toulouse France
| | - Maxime Pineaux
- Laboratoire Evolution et Diversité Biologique (EDB) UMR5174 Université Toulouse 3 Paul Sabatier CNRS, IRD Toulouse France
| | - Pierrick Blanchard
- Laboratoire Evolution et Diversité Biologique (EDB) UMR5174 Université Toulouse 3 Paul Sabatier CNRS, IRD Toulouse France
| | - Joël White
- Laboratoire Evolution et Diversité Biologique (EDB) UMR5174 Université Toulouse 3 Paul Sabatier CNRS, IRD Toulouse France
- ENSFEA Castanet‐Tolosan France
| | - Scott A Hatch
- Institute for Seabird Research and Conservation Anchorage AK 99516 USA
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6
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Huang W, Dicks KL, Hadfield JD, Johnston SE, Ballingall KT, Pemberton JM. Contemporary selection on MHC genes in a free-living ruminant population. Ecol Lett 2022; 25:828-838. [PMID: 35050541 PMCID: PMC9306867 DOI: 10.1111/ele.13957] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/21/2021] [Accepted: 12/08/2021] [Indexed: 11/27/2022]
Abstract
Genes within the major histocompatibility complex (MHC) are the most variable identified in vertebrates. Pathogen-mediated selection is believed to be the main force maintaining MHC diversity. However, relatively few studies have demonstrated contemporary selection on MHC genes. Here, we examine associations between MHC variation and several fitness measurements including total fitness and five fitness components, in 3400 wild Soay sheep (Ovis aries) monitored between 1989 and 2012. In terms of total fitness, measured as lifetime breeding success of all individuals born, we found haplotypes named C and D were associated with decreased and increased male total fitness respectively. In terms of fitness components, juvenile survival was associated with haplotype divergence while individual haplotypes (C, D and F) were associated with adult fitness components. Consistent with the increased male total fitness, the rarest haplotype D has increased in frequency throughout the study period more than expected under neutral expectations. Our results demonstrate contemporary natural selection is acting on MHC class II genes in Soay sheep and the mode of selection on specific fitness components can be different mode from selection on total fitness.
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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.,Royal Zoological Society of Scotland, Edinburgh, UK
| | - Jarrod D Hadfield
- 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
| | | | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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7
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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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8
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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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9
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Cheng Y, Grueber C, Hogg CJ, Belov K. Improved high-throughput MHC typing for non-model species using long-read sequencing. Mol Ecol Resour 2021; 22:862-876. [PMID: 34551192 PMCID: PMC9293008 DOI: 10.1111/1755-0998.13511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/26/2021] [Accepted: 09/06/2021] [Indexed: 11/29/2022]
Abstract
The major histocompatibility complex (MHC) plays a critical role in the vertebrate immune system. Accurate MHC typing is critical to understanding not only host fitness and disease susceptibility, but also the mechanisms underlying host‐pathogen co‐evolution. However, due to the high degree of gene duplication and diversification of MHC genes, it is often technically challenging to accurately characterise MHC genetic diversity in non‐model species. Here we conducted a systematic review to identify common issues associated with current widely used MHC typing approaches. Then to overcome these challenges, we developed a long‐read based MHC typing method along with a new analysis pipeline. Our approach enables the sequencing of fully phased MHC alleles spanning all key functional domains and the separation of highly similar alleles as well as the removal of technical artefacts such as PCR heteroduplexes and chimeras. Using this approach, we performed population‐scale MHC typing in the Tasmanian devil (Sarcophilus harrisii), revealing previously undiscovered MHC functional diversity in this endangered species. Our new method provides a better solution for addressing research questions that require high MHC typing accuracy. Since the method is not limited by species or the number of genes analysed, it will be applicable for studying not only the MHC but also other complex gene families.
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Affiliation(s)
- Yuanyuan Cheng
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Catherine Grueber
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Carolyn J Hogg
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia.,San Diego Zoo Wildlife Alliance, San Diego, California, USA
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
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