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Minias P, Edwards SV, Babik W. Ancient duplication, coevolution, and selection at the MHC class IIA and IIB genes of birds. Front Immunol 2023; 14:1250824. [PMID: 37965325 PMCID: PMC10641522 DOI: 10.3389/fimmu.2023.1250824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/18/2023] [Indexed: 11/16/2023] Open
Abstract
Introduction The Major Histocompatibility Complex (MHC) of vertebrates is a dynamically evolving multigene family primarily responsible for recognizing non-self peptide antigens and triggering a pathogen-specific adaptive immune response. In birds, the MHC was previously thought to evolve via concerted evolution with high degree of gene homogenization and the rapid loss of orthology. However, the discovery of two ancient avian MHC-IIB gene lineages (DAB1 and DAB2) originating before the radiation of extant birds indicated that despite the action of concerted evolution, orthology may be detectable for long evolutionary periods. Methods Here, we take advantage of rapidly accumulating digital genomic resources to search for the signal of an ancient duplication at the avian MHC-IIA genes, as well as to compare phylogenetic distribution and selection between MHC-IIA and IIB gene lineages. Results The analysis of MHC sequences from over 230 species representing ca. 70 bird families revealed the presence of two ancient MHC-IIA gene lineages (DAA1 and DAA2) and showed that their phylogenetic distribution matches exactly the distribution of DAB1 and DAB2 lineages, suggesting tight coevolution. The early post-duplication divergence of DAA1 and DAA2 was driven by positive selection fixing radical amino acid differences within the membrane-proximal domain and, most probably, being functionally related to the interactions between α2 and β2 chains of the MHC-II heterodimer. We detected no evidence for an overall (gene-wide) relaxation or intensification of selection at either DAA1/DAB1 or DAA2/DAB2, but codon-specific differences in selection signature were found at the peptide-binding sites between the two gene lineages, perhaps implying specialization to different pathogen regimes. Discussion Our results suggest that specific pairing of MHC-II α and β chains may have an adaptive significance, a conclusion that advances knowledge on the macroevolution of the avian MHC-II and opens exciting novel directions for future research.
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Affiliation(s)
- Piotr Minias
- University of Lodz, Faculty of Biology and Environmental Protection, Department of Biodiversity Studies and Bioeducation, Lodz, Poland
| | - Scott V. Edwards
- Harvard University, Museum of Comparative Zoology, Cambridge, MA, United States
- Harvard University, Department of Organismic and Evolutionary Biology, Cambridge, MA, United States
| | - Wiesław Babik
- Jagiellonian University, Institute of Environmental Sciences, Faculty of Biology, Kraków, Poland
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Lozano-Martín C, Bracamonte SE, Barluenga M. Evolution of MHC IIB Diversity Across Cichlid Fish Radiations. Genome Biol Evol 2023; 15:evad110. [PMID: 37314153 PMCID: PMC10306275 DOI: 10.1093/gbe/evad110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 05/12/2023] [Accepted: 06/08/2023] [Indexed: 06/15/2023] Open
Abstract
The genes of the major histocompatibility complex (MHC) are among the most polymorphic genes in vertebrates and crucial for their adaptive immune response. These genes frequently show inconsistencies between allelic genealogies and species phylogenies. This phenomenon is thought to be the result of parasite-mediated balancing selection maintaining ancient alleles through speciation events (trans-species polymorphism [TSP]). However, allele similarities may also arise from postspeciation mechanisms, such as convergence or introgression. Here, we investigated the evolution of MHC class IIB diversity in the cichlid fish radiations across Africa and the Neotropics by a comprehensive review of available MHC IIB DNA sequence information. We explored what mechanism explains the MHC allele similarities found among cichlid radiations. Our results showed extensive allele similarity among cichlid fish across continents, likely due to TSP. Functionality at MHC was also shared among species of the different continents. The maintenance of MHC alleles for long evolutionary times and their shared functionality may imply that certain MHC variants are essential in immune adaptation, even in species that diverged millions of years ago and occupy different environments.
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Ren X, Liu Y, Zhao Y, Li B, Bai D, Bou G, Zhang X, Du M, Wang X, Bou T, Shen Y, Dugarjaviin M. Analysis of the Whole-Genome Sequences from an Equus Parent-Offspring Trio Provides Insight into the Genomic Incompatibilities in the Hybrid Mule. Genes (Basel) 2022; 13:genes13122188. [PMID: 36553455 PMCID: PMC9778318 DOI: 10.3390/genes13122188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/07/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Interspecific hybridization often shows negative effects on hybrids. However, only a few multicellular species, limited to a handful of plants and animals, have shown partial genetic mechanisms by which hybridization leads to low fitness in hybrids. Here, to explore the outcome of combining the two genomes of a horse and donkey, we analyzed the whole-genome sequences from an Equus parent-offspring trio using Illumina platforms. We generated 41.39× and 46.21× coverage sequences for the horse and mule, respectively. For the donkey, a 40.38× coverage sequence was generated and stored in our laboratory. Approximately 24.86 million alleles were discovered that varied from the reference genome. Single nucleotide polymorphisms were used as polymorphic markers for assigning alleles to their parental genomic inheritance. We identified 25,703 Mendelian inheritance error single nucleotide polymorphisms in the mule genome that were not inherited from the parents through Mendelian inheritance. A total of 555 de novo single nucleotide polymorphisms were also identified. The rate of de novo single nucleotide polymorphisms was 2.21 × 10-7 in the mule from the Equus parent-offspring trio. This rate is obviously higher than the natural mutation rate for Equus, which is also consistent with the previous hypothesis that interracial crosses may have a high mutation rate. The genes associated with these single nucleotide polymorphisms are mainly involved in immune processes, DNA repair, and cancer processes. The results of the analysis of three genomes from an Equus parent-offspring trio improved our knowledge of the consequences of the integration of parental genomes in mules.
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Performance Comparison of Different Approaches in Genotyping MHC-DRB: The Contrast between Single-Locus and Multi-Locus Species. Animals (Basel) 2022; 12:ani12182452. [PMID: 36139311 PMCID: PMC9495155 DOI: 10.3390/ani12182452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 11/17/2022] Open
Abstract
Major histocompatibility complex (MHC) genes are widely recognised as valuable markers for wildlife genetic studies given their extreme polymorphism and functional importance in fitness-related traits. Newly developed genotyping methods, which rely on the use of next-generation sequencing (NGS), are gradually replacing traditional cloning and Sanger sequencing methods in MHC genotyping studies. Allele calling in NGS methods remains challenging due to extreme polymorphism and locus multiplication in the MHC coupled with allele amplification bias and the generation of artificial sequences. In this study, we compared the performance of molecular cloning with Illumina and Ion Torrent NGS sequencing in MHC-DRB genotyping of single-locus species (roe deer) and species with multiple DRB loci (red deer) in an attempt to adopt a reliable and straightforward method that does not require complex bioinformatic analyses. Our results show that all methods work similarly well in roe deer, but we demonstrate non-consistency in results across methods in red deer. With Illumina sequencing, we detected a maximum number of alleles in 10 red deer individuals (42), while other methods were somewhat less accurate as they scored 69–81% of alleles detected with Illumina sequencing.
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Minias P, Włodarczyk R, Remisiewicz M, Cobzaru I, Janiszewski T. Distinct evolutionary trajectories of MHC class I and class II genes in Old World finches and buntings. Heredity (Edinb) 2021; 126:974-990. [PMID: 33824536 PMCID: PMC8178356 DOI: 10.1038/s41437-021-00427-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 03/08/2021] [Accepted: 03/15/2021] [Indexed: 02/01/2023] Open
Abstract
Major histocompatibility complex (MHC) genes code for key proteins of the adaptive immune system, which present antigens from intra-cellular (MHC class I) and extra-cellular (MHC class II) pathogens. Because of their unprecedented diversity, MHC genes have long been an object of scientific interest, but due to methodological difficulties in genotyping of duplicated loci, our knowledge on the evolution of the MHC across different vertebrate lineages is still limited. Here, we compared the evolution of MHC class I and class II genes in three sister clades of common passerine birds, finches (Fringillinae and Carduelinae) and buntings (Emberizidae) using a uniform methodological (genotyping and data processing) approach and uniform sample sizes. Our analyses revealed contrasting evolutionary trajectories of the two MHC classes. We found a stronger signature of pervasive positive selection and higher allele diversity (allele numbers) at the MHC class I than class II. In contrast, MHC class II genes showed greater allele divergence (in terms of nucleotide diversity) and a much stronger recombination (gene conversion) signal. Gene copy numbers at both MHC class I and class II evolved via fluctuating selection and drift (Brownian Motion evolution), but the evolutionary rate was higher at class I. Our study constitutes one of few existing examples, where evolution of MHC class I and class II genes was directly compared using a multi-species approach. We recommend that re-focusing MHC research from single-species and single-class approaches towards multi-species analyses of both MHC classes can substantially increase our understanding MHC evolution in a broad phylogenetic context.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland.
| | - Radosław Włodarczyk
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Magdalena Remisiewicz
- Bird Migration Research Station, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Ioana Cobzaru
- Institute of Biology Bucharest, Romanian Academy, Bucharest, Romania
| | - Tomasz Janiszewski
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
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6
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Ghani MU, Bo L, Buyang A, Yanchun X, Hussain S, Yasir M. Molecular Characterization of MHC Class I Genes in Four Species of the Turdidae Family to Assess Genetic Diversity and Selection. BIOMED RESEARCH INTERNATIONAL 2021; 2021:5585687. [PMID: 33937397 PMCID: PMC8055405 DOI: 10.1155/2021/5585687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/09/2021] [Accepted: 03/19/2021] [Indexed: 11/17/2022]
Abstract
In vertebrate animals, the molecules encoded by major histocompatibility complex (MHC) genes play an essential role in the adaptive immunity. MHC class I deals with intracellular pathogens (virus) in birds. MHC class I diversity depends on the consequence of local and global environment selective pressure and gene flow. Here, we evaluated the MHC class I gene in four species of the Turdidae family from a broad geographical area of northeast China. We isolated 77 MHC class I sequences, including 47 putatively functional sequences and 30 pseudosequences from 80 individuals. Using the method based on analysis of cloned amplicons (n = 25) for each species, we found two and seven MHC I sequences per individual indicating more than one MHC I locus identified in all sampled species. Results revealed an overall elevated genetic diversity at MHC class I, evidence of different selection patterns among the domains of PBR and non-PBR. Alleles are found to be divergent with overall polymorphic sites per species ranging between 58 and 70 (out of 291 sites). Moreover, transspecies alleles were evident due to convergent evolution or recent speciation for the genus. Phylogenetic relationships among MHC I show an intermingling of alleles clustering among the Turdidae family rather than between other passerines. Pronounced MHC I gene diversity is essential for the existence of species. Our study signifies a valuable tool for the characterization of evolutionary relevant difference across a population of birds with high conservational concerns.
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Affiliation(s)
- Muhammad Usman Ghani
- College of Wildlife Resources and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Li Bo
- College of Wildlife Resources and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - An Buyang
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Science, Kyushu University, Fukuoka 810-0000, Japan
| | - Xu Yanchun
- College of Wildlife Resources and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Shakeel Hussain
- College of Wildlife Resources and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Muhammad Yasir
- Department of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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Gillingham MAF, Montero BK, Wihelm K, Grudzus K, Sommer S, Santos PSC. A novel workflow to improve genotyping of multigene families in wildlife species: An experimental set-up with a known model system. Mol Ecol Resour 2020; 21:982-998. [PMID: 33113273 DOI: 10.1111/1755-0998.13290] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 10/19/2020] [Accepted: 10/22/2020] [Indexed: 12/30/2022]
Abstract
Genotyping complex multigene families in novel systems is particularly challenging. Target primers frequently amplify simultaneously multiple loci leading to high PCR and sequencing artefacts such as chimeras and allele amplification bias. Most genotyping pipelines have been validated in nonmodel systems whereby the real genotype is unknown and the generation of artefacts may be highly repeatable. Further hindering accurate genotyping, the relationship between artefacts and genotype complexity (i.e. number of alleles per genotype) within a PCR remains poorly described. Here, we investigated the latter by experimentally combining multiple known major histocompatibility complex (MHC) haplotypes of a model organism (chicken, Gallus gallus, 43 artificial genotypes with 2-13 alleles per amplicon). In addition to well-defined 'optimal' primers, we simulated a nonmodel species situation by designing 'cross-species' primers based on sequence data from closely related Galliform species. We applied a novel open-source genotyping pipeline (ACACIA; https://gitlab.com/psc_santos/ACACIA), and compared its performance with another, previously published pipeline (AmpliSAS). Allele calling accuracy was higher when using ACACIA (98.5% versus 97% and 77.8% versus 75% for the 'optimal' and 'cross-species' data sets, respectively). Systematic allele dropout of three alleles owing to primer mismatch in the 'cross-species' data set explained high allele calling repeatability (100% when using ACACIA) despite low accuracy, demonstrating that repeatability can be misleading when evaluating genotyping workflows. Genotype complexity was positively associated with nonchimeric artefacts, chimeric artefacts (nonlinearly by levelling when amplifying more than 4-6 alleles) and allele amplification bias. Our study exemplifies and demonstrates pitfalls researchers should avoid to reliably genotype complex multigene families.
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Affiliation(s)
- Mark A F Gillingham
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm Universität, Ulm, Germany
| | - B Karina Montero
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm Universität, Ulm, Germany.,Zoological Institute, Animal Ecology and Conservation, Biocenter Grindel, Universität Hamburg, Hamburg,, Germany
| | - Kerstin Wihelm
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm Universität, Ulm, Germany
| | - Kara Grudzus
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm Universität, Ulm, Germany
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm Universität, Ulm, Germany
| | - Pablo S C Santos
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm Universität, Ulm, Germany
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8
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E GX, Chen LP, Zhou DK, Yang BG, Zhang JH, Zhao YJ, Hong QH, Ma YH, Chu MX, Zhang LP, Basang WD, Zhu YB, Han YG, Na RS, Zeng Y, Zhao ZQ, Huang YF, Han JL. Evolutionary relationship and population structure of domestic Bovidae animals based on MHC-linked and neutral autosomal microsatellite markers. Mol Immunol 2020; 124:83-90. [PMID: 32544655 DOI: 10.1016/j.molimm.2020.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/21/2020] [Accepted: 05/07/2020] [Indexed: 11/26/2022]
Abstract
Major histocompatibility complex (MHC) genes are critical for disease resistance or susceptibility responsible for host-pathogen interactions determined mainly by extensive polymorphisms in the MHC genes. Here, we examined the diversity and phylogenetic pattern of MHC haplotypes reconstructed using three MHC-linked microsatellite markers in 55 populations of five Bovidae species and compared them with those based on neutral autosomal microsatellite markers (NAMs). Three-hundred-and-forty MHC haplotypes were identified in 1453 Bovidae individuals, suggesting significantly higher polymorphism and heterozygosity compared with those based on NAMs. The ambitious boundaries in population differentiation (phylogenetic network, pairwise FST and STRUCTURE analyses) within and between species assessed using the MHC haplotypes were different from those revealed by NAMs associated closely with speciation, geographical distribution, domestication and management histories. In addition, the mean FST was significantly correlated negatively with the number of observed alleles (NA), observed (HO) and expected (HE) heterozygosity and polymorphism information content (PIC) (P < 0.05) in the MHC haplotype dataset while there was no correction of the mean FST estimates (P> 0.05) between the MHC haplotype and NAMs datasets. Analysis of molecular variance (AMOVA) revealed a lower percentage of total variance (PTV) between species/groups based on the MHC-linked microsatellites than NAMs. Therefore, it was inferred that individuals within populations accumulated as many MHC variants as possible to increase their heterozygosity and thus the survival rate of their affiliated populations and species, which eventually reduced population differentiation and thereby complicated their classification and phylogenetic relationship inference. In summary, host-pathogen coevolution and heterozygote advantage, rather than demographic history, act as key driving forces shaping the MHC diversity within the populations and determining the interspecific MHC diversity.
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Affiliation(s)
- Guang-Xin E
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Li-Peng Chen
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Dong-Ke Zhou
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Bai-Gao Yang
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Jia-Hua Zhang
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Yong-Ju Zhao
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Qiong-Hua Hong
- Yunnan Animal Science and Veterinary Institute, Kunming 650224, China
| | - Yue-Hui Ma
- Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
| | - Ming-Xing Chu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
| | - Lu-Pei Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
| | - Wang-Dui Basang
- State Key Laboratory of Barley and Yak Germplasm Resources and Genetic Improvement (Tibet Academy of Agricultural and Animal Husbandry Science (TAAAS)), Lhasa 850002, China
| | - Yan-Bin Zhu
- State Key Laboratory of Barley and Yak Germplasm Resources and Genetic Improvement (Tibet Academy of Agricultural and Animal Husbandry Science (TAAAS)), Lhasa 850002, China
| | - Yan-Guo Han
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Ri-Su Na
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Yan Zeng
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Zhong-Quan Zhao
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Yong-Fu Huang
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China.
| | - Jian-Lin Han
- CAAS-ILRI Joint Laboratory on Livestock and Forage Genetic Resources Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China; Livestock Genetics Program, International Livestock Research Institute (ILRI), Nairobi 00100, Kenya.
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Sagonas K, Runemark A, Antoniou A, Lymberakis P, Pafilis P, Valakos ED, Poulakakis N, Hansson B. Selection, drift, and introgression shape MHC polymorphism in lizards. Heredity (Edinb) 2019; 122:468-484. [PMID: 30258107 PMCID: PMC6460769 DOI: 10.1038/s41437-018-0146-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 07/27/2018] [Accepted: 08/09/2018] [Indexed: 01/12/2023] Open
Abstract
The major histocompatibility complex (MHC) has long served as a model for the evolution of adaptive genetic diversity in wild populations. Pathogen-mediated selection is thought to be a main driver of MHC diversity, but it remains elusive to what degree selection shapes MHC diversity in complex biogeographical scenarios where other evolutionary processes (e.g. genetic drift and introgression) may also be acting. Here we focus on two closely related green lizard species, Lacerta trilineata and L. viridis, to address the evolutionary forces acting on MHC diversity in populations with different biogeographic structure. We characterized MHC class I exon 2 and exon 3, and neutral diversity (microsatellites), to study the relative importance of selection, drift, and introgression in shaping MHC diversity. As expected, positive selection was a significant force shaping the high diversity of MHC genes in both species. Moreover, introgression significantly increased MHC diversity in mainland populations, with a primary direction of gene flow from L. viridis to L. trilineata. Finally, we found significantly fewer MHC alleles in island populations, but maintained MHC sequence and functional diversity, suggesting that positive selection counteracted the effect of drift. Overall, our data support that different evolutionary processes govern MHC diversity in different biogeographical scenarios: positive selection occurs broadly while introgression acts in sympatry and drift when the population sizes decrease.
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Affiliation(s)
- K Sagonas
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK.
- Department of Human and Animal Physiology, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimioupoli Zografou, 15784, Athens, Greece.
| | - A Runemark
- Department of Biology, Lund University, Ecology Building, SE-223 62, Lund, Sweden
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - A Antoniou
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, 71003, Heraklion, Crete, Greece
| | - P Lymberakis
- Natural History Museum of Crete, School of Sciences and Engineering, University of Crete, 71409, Heraklion, Crete, Greece
| | - P Pafilis
- Department of Zoology and Marine Biology, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimioupoli Zografou, 15784, Athens, Greece
| | - E D Valakos
- Department of Human and Animal Physiology, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimioupoli Zografou, 15784, Athens, Greece
| | - N Poulakakis
- Natural History Museum of Crete, School of Sciences and Engineering, University of Crete, 71409, Heraklion, Crete, Greece
- Department of Biology, School of Sciences and Engineering, University of Crete, Vasilika Vouton, 71003, Heraklion, Crete, Greece
| | - B Hansson
- Department of Biology, Lund University, Ecology Building, SE-223 62, Lund, Sweden
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Minias P, Pikus E, Anderwald D. Allelic diversity and selection at the MHC class I and class II in a bottlenecked bird of prey, the White-tailed Eagle. BMC Evol Biol 2019; 19:2. [PMID: 30611206 PMCID: PMC6321662 DOI: 10.1186/s12862-018-1338-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/17/2018] [Indexed: 01/07/2023] Open
Abstract
Background Genes of the Major Histocompatibility Complex (MHC) are essential for adaptive immune response in vertebrates, as they encode receptors that recognize peptides derived from the processing of intracellular (MHC class I) and extracellular (MHC class II) pathogens. High MHC diversity in natural populations is primarily generated and maintained by pathogen-mediated diversifying and balancing selection. It is, however, debated whether selection at the MHC can counterbalance the effects of drift in bottlenecked populations. The aim of this study was to assess allelic diversity of MHC genes in a recently bottlenecked bird of prey, the White-tailed Eagle Haliaeetus albicilla, as well as to compare mechanisms that shaped the evolution of MHC class I and class II in this species. Results We showed that significant levels of MHC diversity were retained in the core Central European (Polish) population of White-tailed Eagles. Ten MHC class I and 17 MHC class II alleles were recovered in total and individual birds showed high average MHC diversity (3.80 and 6.48 MHC class I and class II alleles per individual, respectively). Distribution of alleles within individuals provided evidence for the presence of at least three class I and five class II loci the White-tailed Eagle, which suggests recent duplication events. MHC class II showed greater sequence polymorphism than MHC class I and there was much stronger signature of diversifying selection acting on MHC class II than class I. Phylogenetic analysis provided evidence for trans-species similarity of class II, but not class I, sequences, which is likely consistent with stronger balancing selection at MHC class II. Conclusions Relatively high MHC diversity retained in the White-tailed Eagles from northern Poland reinforces high conservation value of local eagle populations. At the same time, our study is the first to demonstrate contrasting patterns of allelic diversity and selection at MHC class I and class II in an accipitrid species, supporting the hypothesis that different mechanisms can shape evolutionary trajectories of MHC class I and class II genes. Electronic supplementary material The online version of this article (10.1186/s12862-018-1338-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland.
| | - Ewa Pikus
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland
| | - Dariusz Anderwald
- Eagle Conservation Committee, Niepodległości 53/55, 10-044, Olsztyn, Poland
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11
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Kaesler E, Kappeler PM, Brameier M, Demeler J, Kraus C, Rakotoniaina JH, Hämäläinen AM, Huchard E. Shared evolutionary origin of major histocompatibility complex polymorphism in sympatric lemurs. Mol Ecol 2017; 26:5629-5645. [PMID: 28833696 DOI: 10.1111/mec.14336] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 07/12/2017] [Accepted: 08/05/2017] [Indexed: 12/11/2022]
Abstract
Genes of the major histocompatibility complex (MHC) play a central role in adaptive immune responses of vertebrates. They exhibit remarkable polymorphism, often crossing species boundaries with similar alleles or allelic motifs shared across species. This pattern may reflect parallel parasite-mediated selective pressures, either favouring the long maintenance of ancestral MHC allelic lineages across successive speciation events by balancing selection ("trans-species polymorphism"), or alternatively favouring the independent emergence of functionally similar alleles post-speciation via convergent evolution. Here, we investigate the origins of MHC similarity across several species of dwarf and mouse lemurs (Cheirogaleidae). We examined MHC class II variation in two highly polymorphic loci (DRB, DQB) and evaluated the overlap of gut-parasite communities in four sympatric lemurs. We tested for parasite-MHC associations across species to determine whether similar parasite pressures may select for similar MHC alleles in different species. Next, we integrated our MHC data with those previously obtained from other Cheirogaleidae to investigate the relative contribution of convergent evolution and co-ancestry to shared MHC polymorphism by contrasting patterns of codon usage at functional vs. neutral sites. Our results indicate that parasites shared across species may select for functionally similar MHC alleles, implying that the dynamics of MHC-parasite co-evolution should be envisaged at the community level. We further show that balancing selection maintaining trans-species polymorphism, rather than convergent evolution, is the primary mechanism explaining shared MHC sequence motifs between species that diverged up to 30 million years ago.
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Affiliation(s)
- Eva Kaesler
- Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung, Verhaltensökologie & Soziobiologie, Göttingen, Germany
| | - Peter M Kappeler
- Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung, Verhaltensökologie & Soziobiologie, Göttingen, Germany.,Johann Friedrich Blumenbach Institut für Zoologie & Anthropologie, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Markus Brameier
- Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung, Göttingen, Germany
| | - Janina Demeler
- Institut für Parasitologie und Tropenveterinärmedizin, Berlin, Germany
| | - Cornelia Kraus
- Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung, Verhaltensökologie & Soziobiologie, Göttingen, Germany.,Johann Friedrich Blumenbach Institut für Zoologie & Anthropologie, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Josué H Rakotoniaina
- Johann Friedrich Blumenbach Institut für Zoologie & Anthropologie, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Anni M Hämäläinen
- Johann Friedrich Blumenbach Institut für Zoologie & Anthropologie, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Elise Huchard
- Institute for Evolutionary Biology, Montpellier (ISEM, UMR 5554), CNRS, Université Montpellier, Montpellier Cedex 5, France
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12
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Marmesat E, Schmidt K, Saveljev AP, Seryodkin IV, Godoy JA. Retention of functional variation despite extreme genomic erosion: MHC allelic repertoires in the Lynx genus. BMC Evol Biol 2017; 17:158. [PMID: 28676046 PMCID: PMC5496644 DOI: 10.1186/s12862-017-1006-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/23/2017] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Demographic bottlenecks erode genetic diversity and may increase endangered species' extinction risk via decreased fitness and adaptive potential. The genetic status of species is generally assessed using neutral markers, whose dynamic can differ from that of functional variation due to selection. The MHC is a multigene family described as the most important genetic component of the mammalian immune system, with broad implications in ecology and evolution. The genus Lynx includes four species differing immensely in demographic history and population size, which provides a suitable model to study the genetic consequences of demographic declines: the Iberian lynx being an extremely bottlenecked species and the three remaining ones representing common and widely distributed species. We compared variation in the most variable exon of the MHCI and MHCII-DRB loci among the four species of the Lynx genus. RESULTS The Iberian lynx was characterised by lower number of MHC alleles than its sister species (the Eurasian lynx). However, it maintained most of the functional genetic variation at MHC loci present in the remaining and genetically healthier lynx species at all nucleotide, amino acid, and supertype levels. CONCLUSIONS Species-wide functional genetic diversity can be maintained even in the face of severe population bottlenecks, which caused devastating whole genome genetic erosion. This could be the consequence of divergent alleles being retained across paralogous loci, an outcome that, in the face of frequent gene conversion, may have been favoured by balancing selection.
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Affiliation(s)
- Elena Marmesat
- Department of Integrative Ecology, Estación Biológica de Doñana (CSIC), C/Américo Vespucio, 26, 41092, Sevilla, Spain
| | - Krzysztof Schmidt
- Mammal Research Institute, Polish Academy of Sciences, 17-230, Białowieża, Poland
| | - Alexander P Saveljev
- Department of Animal Ecology, Russian Research Institute of Game Management and Fur Farming, 79 Preobrazhenskaya Str, Kirov, 610000, Russia
| | - Ivan V Seryodkin
- Laboratory of Ecology and Conservation of Animals, Pacific Institute of Geography of Far East Branch of Russian Academy of Sciences, 7 Radio Street, Vladivostok, 690041, Russia
- Far Eastern Federal University, 8 Sukhanova Street, Vladivostok, 690091, Russia
| | - José A Godoy
- Department of Integrative Ecology, Estación Biológica de Doñana (CSIC), C/Américo Vespucio, 26, 41092, Sevilla, Spain.
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13
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Gillingham MAF, Béchet A, Courtiol A, Rendón-Martos M, Amat JA, Samraoui B, Onmuş O, Sommer S, Cézilly F. Very high MHC Class IIB diversity without spatial differentiation in the mediterranean population of greater Flamingos. BMC Evol Biol 2017; 17:56. [PMID: 28219340 PMCID: PMC5319168 DOI: 10.1186/s12862-017-0905-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 02/06/2017] [Indexed: 02/07/2023] Open
Abstract
Background Selective pressure from pathogens is thought to shape the allelic diversity of major histocompatibility complex (MHC) genes in vertebrates. In particular, both local adaptation to pathogens and gene flow are thought to explain a large part of the intraspecific variation observed in MHC allelic diversity. To date, however, evidence that adaptation to locally prevalent pathogens maintains MHC variation is limited to species with limited dispersal and, hence, reduced gene flow. On the one hand high gene flow can disrupt local adaptation in species with high dispersal rates, on the other hand such species are much more likely to experience spatial variation in pathogen pressure, suggesting that there may be intense pathogen mediated selection pressure operating across breeding sites in panmictic species. Such pathogen mediated selection pressure operating across breeding sites should therefore be sufficient to maintain high MHC diversity in high dispersing species in the absence of local adaptation mechanisms. We used the Greater Flamingo, Phoenicopterus roseus, a long-lived colonial bird showing a homogeneous genetic structure of neutral markers at the scale of the Mediterranean region, to test the prediction that higher MHC allelic diversity with no population structure should occur in large panmictic populations of long-distance dispersing birds than in other resident species. Results We assessed the level of allelic diversity at the MHC Class IIB exon 2 from 116 individuals born in four different breeding colonies of Greater Flamingo in the Mediterranean region. We found one of the highest allelic diversity (109 alleles, 2 loci) of any non-passerine avian species investigated so far relative to the number of individuals and loci genotyped. There was no evidence of population structure between the four major Mediterranean breeding colonies. Conclusion Our results suggest that local adaptation at MHC Class IIB in Greater Flamingos is constrained by high gene flow and high MHC diversity appears to be maintained by population wide pathogen-mediated selection rather than local pathogen-mediated selection. Further understanding of how pathogens vary across space and time will be crucial to further elucidate the mechanisms maintaining MHC diversity in species with large panmictic populations and high dispersal rates. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0905-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mark A F Gillingham
- University of Ulm, Institute of Evolutionary Ecology and Conservation Genomics, Albert-Einstein Allee 11, D-89069, Ulm, Germany. .,Université de Bourgogne, Equipe Ecologie Evolutive, UMR CNRS 6282 Biogéosciences, 6 bd. Gabriel, 21000, Dijon, France. .,Centre de Recherche de la Tour du Valat, Le Sambuc, 13200, Arles, France. .,Leibniz Institute for Zoo and Wildlife Research, Evolutionary Genetics, Alfred-Kowalke-Str. 17, D-10315, Berlin, Germany.
| | - Arnaud Béchet
- Centre de Recherche de la Tour du Valat, Le Sambuc, 13200, Arles, France
| | - Alexandre Courtiol
- Leibniz Institute for Zoo and Wildlife Research, Evolutionary Genetics, Alfred-Kowalke-Str. 17, D-10315, Berlin, Germany.,Berlin Center for Genomics in Biodiversity Research (BeGenDiv), D-14195, Berlin, Germany
| | - Manuel Rendón-Martos
- R.N. Laguna de Fuente de Piedra, Consejería de Medio Ambiente y Ordenación del Territorio, Junta de Andalucía, Apartado 1, E-29520 Fuente de Piedra, (Málaga), Spain
| | - Juan A Amat
- Department of Wetland Ecology, Estación Biológica de Doñana, (EBD-CSIC), calle Américo Vespucio s/n, E-41092, Sevilla, Spain
| | - Boudjéma Samraoui
- Center of Excellence for Research in Biodiversity, King Saud University, Riyadh, Saudi Arabia.,Laboratoire de recherche et de conservation des zones humides, University of Guelma, Guelma, Algeria
| | - Ortaç Onmuş
- Natural History Museum, Faculty of Sciences, Department of Biology, Ege University, Bornova, İzmir, Turkey
| | - Simone Sommer
- University of Ulm, Institute of Evolutionary Ecology and Conservation Genomics, Albert-Einstein Allee 11, D-89069, Ulm, Germany
| | - Frank Cézilly
- Université de Bourgogne, Equipe Ecologie Evolutive, UMR CNRS 6282 Biogéosciences, 6 bd. Gabriel, 21000, Dijon, France.,Institut Universitaire de France, Paris, France
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