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Minias P. Evolutionary variation in gene conversion at the avian MHC is explained by fluctuating selection, gene copy numbers and life history. Mol Ecol 2024; 33:e17453. [PMID: 38953291 DOI: 10.1111/mec.17453] [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: 01/08/2024] [Revised: 06/05/2024] [Accepted: 06/14/2024] [Indexed: 07/03/2024]
Abstract
The major histocompatibility complex (MHC) multigene family encodes key pathogen-recognition molecules of the vertebrate adaptive immune system. Hyper-polymorphism of MHC genes is de novo generated by point mutations, but new haplotypes may also arise by re-shuffling of existing variation through intra- and inter-locus gene conversion. Although the occurrence of gene conversion at the MHC has been known for decades, we still have limited understanding of its functional importance. Here, I took advantage of extensive genetic resources (~9000 sequences) to investigate broad scale macroevolutionary patterns in gene conversion processes at the MHC across nearly 200 avian species. Gene conversion was found to constitute a universal mechanism in birds, as 83% of species showed footprints of gene conversion at either MHC class and 25% of all allelic variants were attributed to gene conversion. Gene conversion processes were stronger at MHC-II than MHC-I, but inter-specific variation at both MHC classes was explained by similar evolutionary scenarios, reflecting fluctuating selection towards different optima and drift. Gene conversion showed uneven phylogenetic distribution across birds and was driven by gene copy number variation, supporting significant role of inter-locus gene conversion processes in the evolution of the avian MHC. Finally, MHC gene conversion was stronger in species with fast life histories (high fecundity) and in long-distance migrants, likely reflecting variation in population sizes and host-pathogen coevolutionary dynamics. The results provide a robust comparative framework for understanding macroevolutionary variation in gene conversion at the avian MHC and reinforce important contribution of this mechanism to functional MHC diversity.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
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2
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Minias P, Pap PL, Vincze O, Vágási CI. Correlated evolution of oxidative physiology and MHC-based immunosurveillance in birds. Proc Biol Sci 2024; 291:20240686. [PMID: 38889785 DOI: 10.1098/rspb.2024.0686] [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: 01/12/2024] [Accepted: 05/06/2024] [Indexed: 06/20/2024] Open
Abstract
Maintenance and activation of the immune system incur costs, not only in terms of substrates and energy but also via collateral oxidative damage to host cells or tissues during immune response. So far, associations between immune function and oxidative damage have been primarily investigated at intra-specific scales. Here, we hypothesized that pathogen-driven selection should favour the evolution of effective immunosurveillance mechanisms (e.g. major histocompatibility complex, MHC) and antioxidant defences to mitigate oxidative damage resulting from immune function. Using phylogenetically informed comparative approaches, we provided evidence for the correlated evolution of host oxidative physiology and MHC-based immunosurveillance in birds. Species selected for more robust MHC-based immunosurveillance (higher gene copy numbers and allele diversity) showed stronger antioxidant defences, although selection for MHC diversity still showed a positive evolutionary association with oxidative damage to lipids. Our results indicate that historical pathogen-driven selection for highly duplicated and diverse MHC could have promoted the evolution of efficient antioxidant mechanisms, but these evolutionary solutions may be insufficient to keep oxidative stress at bounds. Although the precise nature of mechanistic links between the MHC and oxidative stress remains unclear, our study suggests that a general evolutionary investment in immune function may require co-adaptations at the level of host oxidative metabolism.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, University of Lodz, Faculty of Biology and Environmental Protection, Banacha 1/3, 90-237 Lodz, Poland
| | - Péter L Pap
- Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Orsolya Vincze
- Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Cluj-Napoca, Romania
- Wetland Ecology Research Group, HUN-REN Centre for Ecological Research, Institute of Aquatic Ecology, Debrecen, Hungary
- ImmunoConcEpT, University of Bordeaux, CNRS UMR 5164, Bordeaux, France
| | - Csongor I Vágási
- Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Cluj-Napoca, Romania
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3
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He K, Liang C, Ma S, Liu H, Zhu Y. Copy number and selection of MHC genes in ruminants are related to habitat, average life span and diet. Gene 2024; 904:148179. [PMID: 38242373 DOI: 10.1016/j.gene.2024.148179] [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: 09/18/2023] [Revised: 12/26/2023] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
The ruminants, as the main group of livestock, have been extensively studied in terms of their physiology, endocrinology, biochemistry, genetics, and nutrition. Despite the wide geographic distribution and habitat diversity of animals in this group, their ecology and evolution remain poorly understood. In this study, we analyzed the gene copy number, selection, and ecological and evolutionary processes that have affected the evolution of major histocompatibility complex (MHC) genes across ruminant lineages based on available genomic data. The 51 species analyzed represented all six families of ruminants. Our finding indicated that the architecture of the MHC region is conserved in ruminants, but with variable copy numbers of MHC-I, MHC-IIA, and MHC-IIB genes. No lineage-specific gene duplication was observed in the MHC genes. The phylogenetic generalized least squares regression (PGLS) model revealed association between ecological and biological factors (habitat and lifespan) and gene duplication in DQA and DQB, but not in DRB. The selection pressure of DQA and DQB were related with lifespan, diet, and the ratio of genetic repeat elements. These results suggest that the MHC evolution in ruminants, including copy number and selection, has been influenced by genetic repeat elements, pathogen exposure risk, and intrinsic cost of possessing multiple MHC genes.
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Affiliation(s)
- Ke He
- College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Hangzhou, China
| | - Chunhong Liang
- College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Hangzhou, China
| | - Shujuan Ma
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu, China
| | - Hongyi Liu
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Ying Zhu
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu, China.
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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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Minias P, Peng WXVH, Matson KD. Evolutionary trade-off between innate and acquired immune defences in birds. Front Zool 2023; 20:32. [PMID: 37684615 PMCID: PMC10486109 DOI: 10.1186/s12983-023-00511-1] [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: 02/03/2023] [Accepted: 09/01/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND The development, maintenance, and use of immune defences are costly. Therefore, animals face trade-offs in terms of resource allocation within their immune system and between their immune system and other physiological processes. To maximize fitness, evolution may favour investment in one immunological defence or subsystem over another in a way that matches a species broader life history strategy. Here, we used phylogenetically-informed comparative analyses to test for relationships between two immunological components. Natural antibodies and complement were used as proxies for the innate branch; structural complexity of the major histocompatibility complex (MHC) region was used for the acquired branch. RESULTS We found a negative association between the levels of natural antibodies (i.e., haemagglutination titre) and the total MHC gene copy number across the avian phylogeny, both at the species and family level. The family-level analysis indicated that this association was apparent for both MHC-I and MHC-II, when copy numbers within these two MHC regions were analysed separately. The association remained significant after controlling for basic life history components and for ecological traits commonly linked to pathogen exposure. CONCLUSION Our results provide the first phylogenetically robust evidence for an evolutionary trade-off within the avian immune system, with a more developed acquired immune system (i.e., more complex MHC architecture) in more derived bird lineages (e.g., passerines) being accompanied by an apparent downregulation of the innate immune system.
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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.
| | - Wei-Xuan V-H Peng
- Wildlife Ecology and Conservation Group, Wageningen University & Research, Droevendaalsesteeg 3a, 6708PB, Wageningen, Netherlands
| | - Kevin D Matson
- Wildlife Ecology and Conservation Group, Wageningen University & Research, Droevendaalsesteeg 3a, 6708PB, Wageningen, Netherlands
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Mellinger S, Stervander M, Lundberg M, Drews A, Westerdahl H. Improved haplotype resolution of highly duplicated MHC genes in a long-read genome assembly using MiSeq amplicons. PeerJ 2023; 11:e15480. [PMID: 37456901 PMCID: PMC10349553 DOI: 10.7717/peerj.15480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/08/2023] [Indexed: 07/18/2023] Open
Abstract
Long-read sequencing offers a great improvement in the assembly of complex genomic regions, such as the major histocompatibility complex (MHC) region, which can contain both tandemly duplicated MHC genes (paralogs) and high repeat content. The MHC genes have expanded in passerine birds, resulting in numerous MHC paralogs, with relatively high sequence similarity, making the assembly of the MHC region challenging even with long-read sequencing. In addition, MHC genes show rather high sequence divergence between alleles, making diploid-aware assemblers incorrectly classify haplotypes from the same locus as sequences originating from different genomic regions. Consequently, the number of MHC paralogs can easily be over- or underestimated in long-read assemblies. We therefore set out to verify the MHC diversity in an original and a haplotype-purged long-read assembly of one great reed warbler Acrocephalus arundinaceus individual (the focal individual) by using Illumina MiSeq amplicon sequencing. Single exons, representing MHC class I (MHC-I) and class IIB (MHC-IIB) alleles, were sequenced in the focal individual and mapped to the annotated MHC alleles in the original long-read genome assembly. Eighty-four percent of the annotated MHC-I alleles in the original long-read genome assembly were detected using 55% of the amplicon alleles and likewise, 78% of the annotated MHC-IIB alleles were detected using 61% of the amplicon alleles, indicating an incomplete annotation of MHC genes. In the haploid genome assembly, each MHC-IIB gene should be represented by one allele. The parental origin of the MHC-IIB amplicon alleles in the focal individual was determined by sequencing MHC-IIB in its parents. Two of five larger scaffolds, containing 6-19 MHC-IIB paralogs, had a maternal and paternal origin, respectively, as well as a high nucleotide similarity, which suggests that these scaffolds had been incorrectly assigned as belonging to different loci in the genome rather than as alternate haplotypes of the same locus. Therefore, the number of MHC-IIB paralogs was overestimated in the haploid genome assembly. Based on our findings we propose amplicon sequencing as a suitable complement to long-read sequencing for independent validation of the number of paralogs in general and for haplotype inference in multigene families in particular.
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Affiliation(s)
- Samantha Mellinger
- Department of Biology, Molecular Ecology and Evolution Lab, Lund University, Lund, Sweden
| | - Martin Stervander
- Department of Biology, Molecular Ecology and Evolution Lab, Lund University, Lund, Sweden
- Department of Biology and Environmental Science, Faculty of Health and Life Sciences, Linnaeus University, Kalmar, Sweden
- Bird Group, Natural History Museum, Tring, Hertfordshire, United Kingdom
| | - Max Lundberg
- Department of Biology, Molecular Ecology and Evolution Lab, Lund University, Lund, Sweden
| | - Anna Drews
- Department of Biology, Molecular Ecology and Evolution Lab, Lund University, Lund, Sweden
| | - Helena Westerdahl
- Department of Biology, Molecular Ecology and Evolution Lab, Lund University, Lund, Sweden
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Eltschkner S, Mellinger S, Buus S, Nielsen M, Paulsson KM, Lindkvist-Petersson K, Westerdahl H. The structure of songbird MHC class I reveals antigen binding that is flexible at the N-terminus and static at the C-terminus. Front Immunol 2023; 14:1209059. [PMID: 37483599 PMCID: PMC10360169 DOI: 10.3389/fimmu.2023.1209059] [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: 04/20/2023] [Accepted: 06/08/2023] [Indexed: 07/25/2023] Open
Abstract
Long-distance migratory animals such as birds and bats have evolved to withstand selection imposed by pathogens across the globe, and pathogen richness is known to be particularly high in tropical regions. Immune genes, so-called Major Histocompatibility Complex (MHC) genes, are highly duplicated in songbirds compared to other vertebrates, and this high MHC diversity has been hypothesised to result in a unique adaptive immunity. To understand the rationale behind the evolution of the high MHC genetic diversity in songbirds, we determined the structural properties of an MHC class I protein, Acar3, from a long-distance migratory songbird, the great reed warbler Acrocephalus arundinaceus (in short: Acar). The structure of Acar3 was studied in complex with pathogen-derived antigens and shows an overall antigen presentation similar to human MHC class I. However, the peptides bound to Acar3 display an unusual conformation: Whereas the N-terminal ends of the peptides display enhanced flexibility, the conformation of their C-terminal halves is rather static. This uncommon peptide-binding mode in Acar3 is facilitated by a central Arg residue within the peptide-binding groove that fixes the backbone of the peptide at its central position, and potentially permits successful interactions between MHC class I and innate immune receptors. Our study highlights the importance of investigating the immune system of wild animals, such as birds and bats, to uncover unique immune mechanisms which may neither exist in humans nor in model organisms.
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Affiliation(s)
- Sandra Eltschkner
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Samantha Mellinger
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Soren Buus
- Department of Experimental Immunology, Institute of International Health, Immunology and Microbiology, Copenhagen, Denmark
| | - Morten Nielsen
- Immunoinformatics and Machine Learning, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Kajsa M. Paulsson
- Antigen Presentation, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Karin Lindkvist-Petersson
- Medical Structural Biology, Department of Experimental Medical Science, Lund University, Lund, Sweden
- LINXS - Institute of Advanced Neutron and X-ray Science, Lund University, Lund, Sweden
| | - Helena Westerdahl
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
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8
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Vinkler M, Fiddaman SR, Těšický M, O'Connor EA, Savage AE, Lenz TL, Smith AL, Kaufman J, Bolnick DI, Davies CS, Dedić N, Flies AS, Samblás MMG, Henschen AE, Novák K, Palomar G, Raven N, Samaké K, Slade J, Veetil NK, Voukali E, Höglund J, Richardson DS, Westerdahl H. Understanding the evolution of immune genes in jawed vertebrates. J Evol Biol 2023; 36:847-873. [PMID: 37255207 PMCID: PMC10247546 DOI: 10.1111/jeb.14181] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 04/23/2023] [Accepted: 04/26/2023] [Indexed: 06/01/2023]
Abstract
Driven by co-evolution with pathogens, host immunity continuously adapts to optimize defence against pathogens within a given environment. Recent advances in genetics, genomics and transcriptomics have enabled a more detailed investigation into how immunogenetic variation shapes the diversity of immune responses seen across domestic and wild animal species. However, a deeper understanding of the diverse molecular mechanisms that shape immunity within and among species is still needed to gain insight into-and generate evolutionary hypotheses on-the ultimate drivers of immunological differences. Here, we discuss current advances in our understanding of molecular evolution underpinning jawed vertebrate immunity. First, we introduce the immunome concept, a framework for characterizing genes involved in immune defence from a comparative perspective, then we outline how immune genes of interest can be identified. Second, we focus on how different selection modes are observed acting across groups of immune genes and propose hypotheses to explain these differences. We then provide an overview of the approaches used so far to study the evolutionary heterogeneity of immune genes on macro and microevolutionary scales. Finally, we discuss some of the current evidence as to how specific pathogens affect the evolution of different groups of immune genes. This review results from the collective discussion on the current key challenges in evolutionary immunology conducted at the ESEB 2021 Online Satellite Symposium: Molecular evolution of the vertebrate immune system, from the lab to natural populations.
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Affiliation(s)
- Michal Vinkler
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | | | - Martin Těšický
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | | | - Anna E. Savage
- Department of BiologyUniversity of Central FloridaFloridaOrlandoUSA
| | - Tobias L. Lenz
- Research Unit for Evolutionary ImmunogenomicsDepartment of BiologyUniversity of HamburgHamburgGermany
| | | | - Jim Kaufman
- Institute for Immunology and Infection ResearchUniversity of EdinburghEdinburghUK
- Department of Veterinary MedicineUniversity of CambridgeCambridgeUK
| | - Daniel I. Bolnick
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticutUSA
| | | | - Neira Dedić
- Department of Botany and ZoologyMasaryk UniversityBrnoCzech Republic
| | - Andrew S. Flies
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - M. Mercedes Gómez Samblás
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
- Department of ParasitologyUniversity of GranadaGranadaSpain
| | | | - Karel Novák
- Department of Genetics and BreedingInstitute of Animal SciencePragueUhříněvesCzech Republic
| | - Gemma Palomar
- Faculty of BiologyInstitute of Environmental SciencesJagiellonian UniversityKrakówPoland
| | - Nynke Raven
- Department of ScienceEngineering and Build EnvironmentDeakin UniversityVictoriaWaurn PondsAustralia
| | - Kalifa Samaké
- Department of Genetics and MicrobiologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | - Joel Slade
- Department of BiologyCalifornia State UniversityFresnoCaliforniaUSA
| | | | - Eleni Voukali
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | - Jacob Höglund
- Department of Ecology and GeneticsUppsala UniversitetUppsalaSweden
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Extensive MHC class IIβ diversity across multiple loci in the small-spotted catshark (Scyliorhinus canicula). Sci Rep 2023; 13:3837. [PMID: 36882519 PMCID: PMC9992475 DOI: 10.1038/s41598-023-30876-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/02/2023] [Indexed: 03/09/2023] Open
Abstract
The major histocompatibility complex (MHC) is a multigene family responsible for pathogen detection, and initiation of adaptive immune responses. Duplication, natural selection, recombination, and their resulting high functional genetic diversity spread across several duplicated loci are the main hallmarks of the MHC. Although these features were described in several jawed vertebrate lineages, a detailed MHC IIβ characterization at the population level is still lacking for chondrichthyans (chimaeras, rays and sharks), i.e. the most basal lineage to possess an MHC-based adaptive immune system. We used the small-spotted catshark (Scyliorhinus canicula, Carcharhiniformes) as a case-study species to characterize MHC IIβ diversity using complementary molecular tools, including publicly available genome and transcriptome datasets, and a newly developed high-throughput Illumina sequencing protocol. We identified three MHC IIβ loci within the same genomic region, all of which are expressed in different tissues. Genetic screening of the exon 2 in 41 individuals of S. canicula from a single population revealed high levels of sequence diversity, evidence for positive selection, and footprints of recombination. Moreover, the results also suggest the presence of copy number variation in MHC IIβ genes. Thus, the small-spotted catshark exhibits characteristics of functional MHC IIβ genes typically observed in other jawed vertebrates.
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Rekdal SL, Anmarkrud JA, Lifjeld JT, Johnsen A. Do female bluethroats without extra-pair offspring have more MHC-compatible social mates? Behav Ecol Sociobiol 2023. [DOI: 10.1007/s00265-023-03311-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Abstract
Genes of the major histocompatibility complex (MHC) are crucial for adaptive immunity in jawed vertebrates, and theory predicts that there should be mate choice for optimizing MHC constitution in the offspring. In a previous study, we demonstrated a non-random female choice of extra-pair males in the bluethroat (Luscinia svecica), yielding offspring that was closer to an intermediate MHC class II (MHCII) allele count than their within-pair halfsiblings. The present study tests whether social pairs with only within-pair young (WPY) in their brood, in the same study population, had a combined MHC-constitution closer to a presumed intermediate optimum, than social pairs with extra-pair young (EPY), with a corresponding pattern in their offspring. As expected, we found that WPY from pure WPY-broods were more MHC-optimal than WPY from mixed broods, but only in broods of young (second year) males. Correspondingly, there was a tendency for social pairs with only WPY in their brood to be more MHC-compatible than social pairs with EPY in their brood, when the male was young. Older bluethroat males have considerably larger testes than young males, and their higher sperm competitiveness could help them secure paternity in their own brood, also when they are not MHC-compatible. In other words, in the sexual conflict over paternity, females may be more likely to realise their preference for a MHC-compatible mate when paired to a young male. As a possible fitness indicator, immune responsiveness to an injected antigen (PHA) was elevated for offspring closer to “the golden mean” in MHCII allele count.
Significance statement
This study contributes to our understanding of MHC-based mate choice in extra-pair mating systems, by showing that female bluethroats (Luscinia svecica) with an MHCII-compatible social mate tend to have no extra-pair young in their brood, but only when the social male is young. This elucidates a possible sexual conflict, in which older social males are able to override female preferences and prevent other males from gaining paternity in their brood through higher sperm production. Studying systems in which extra-pair paternity occurs offers an insight into the genetic benefits of mate choice, as extra-pair males, in contrast to social males, generally contribute only sperm. Further, the strict and thorough genotyping scheme applied in this study enabled us to demonstrate a preference for “the golden mean” in MHC-diversity in a species with one of the highest MHC class II-diversity known to date.
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11
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Karawita AC, Cheng Y, Chew KY, Challagulla A, Kraus R, Mueller RC, Tong MZW, Hulme KD, Bielefeldt-Ohmann H, Steele LE, Wu M, Sng J, Noye E, Bruxner TJ, Au GG, Lowther S, Blommaert J, Suh A, McCauley AJ, Kaur P, Dudchenko O, Aiden E, Fedrigo O, Formenti G, Mountcastle J, Chow W, Martin FJ, Ogeh DN, Thiaud-Nissen F, Howe K, Tracey A, Smith J, Kuo RI, Renfree MB, Kimura T, Sakoda Y, McDougall M, Spencer HG, Pyne M, Tolf C, Waldenström J, Jarvis ED, Baker ML, Burt DW, Short KR. The swan genome and transcriptome, it is not all black and white. Genome Biol 2023; 24:13. [PMID: 36683094 PMCID: PMC9867998 DOI: 10.1186/s13059-022-02838-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 12/12/2022] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND The Australian black swan (Cygnus atratus) is an iconic species with contrasting plumage to that of the closely related northern hemisphere white swans. The relative geographic isolation of the black swan may have resulted in a limited immune repertoire and increased susceptibility to infectious diseases, notably infectious diseases from which Australia has been largely shielded. Unlike mallard ducks and the mute swan (Cygnus olor), the black swan is extremely sensitive to highly pathogenic avian influenza. Understanding this susceptibility has been impaired by the absence of any available swan genome and transcriptome information. RESULTS Here, we generate the first chromosome-length black and mute swan genomes annotated with transcriptome data, all using long-read based pipelines generated for vertebrate species. We use these genomes and transcriptomes to show that unlike other wild waterfowl, black swans lack an expanded immune gene repertoire, lack a key viral pattern-recognition receptor in endothelial cells and mount a poorly controlled inflammatory response to highly pathogenic avian influenza. We also implicate genetic differences in SLC45A2 gene in the iconic plumage of the black swan. CONCLUSION Together, these data suggest that the immune system of the black swan is such that should any avian viral infection become established in its native habitat, the black swan would be in a significant peril.
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Affiliation(s)
- Anjana C Karawita
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, 5 Portarlington Road, Geelong, VIC, 3220, Australia
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Keng Yih Chew
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Arjun Challagulla
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, 5 Portarlington Road, Geelong, VIC, 3220, Australia
| | - Robert Kraus
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, 78315, Germany
- Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| | - Ralf C Mueller
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, 78315, Germany
- Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| | - Marcus Z W Tong
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Katina D Hulme
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Helle Bielefeldt-Ohmann
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Lauren E Steele
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Melanie Wu
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Julian Sng
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Ellesandra Noye
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Timothy J Bruxner
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Gough G Au
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, 5 Portarlington Road, Geelong, VIC, 3220, Australia
| | - Suzanne Lowther
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, 5 Portarlington Road, Geelong, VIC, 3220, Australia
| | - Julie Blommaert
- Department of Organismal Biology - Systematic Biology, Evolutionary Biology Centre, Uppsala University, Science for Life Laboratory, Uppsala, 752 36, Sweden
- The New Zealand Institute for Plant & Food Research Ltd, Nelson, 7010, New Zealand
| | - Alexander Suh
- Department of Organismal Biology - Systematic Biology, Evolutionary Biology Centre, Uppsala University, Science for Life Laboratory, Uppsala, 752 36, Sweden
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TU, UK
| | - Alexander J McCauley
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, 5 Portarlington Road, Geelong, VIC, 3220, Australia
| | - Parwinder Kaur
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia
| | - Olga Dudchenko
- The Centre for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Centre for Theoretical Biological Physics and Department of Computer Science, Rice University, Houston, TX, 77030, USA
| | - Erez Aiden
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia
- The Centre for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Centre for Theoretical Biological Physics and Department of Computer Science, Rice University, Houston, TX, 77030, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech, Pudong, 201210, China
| | - Olivier Fedrigo
- The Vertebrate Genome Laboratory, The Rockefeller University, NY, 10065, USA
| | - Giulio Formenti
- The Vertebrate Genome Laboratory, The Rockefeller University, NY, 10065, USA
| | | | - William Chow
- Tree of Life, Welcome Sanger Institute, Cambridge, CB10 1SA, UK
| | - Fergal J Martin
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Denye N Ogeh
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Françoise Thiaud-Nissen
- National Centre for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Kerstin Howe
- Tree of Life, Welcome Sanger Institute, Cambridge, CB10 1SA, UK
| | - Alan Tracey
- Tree of Life, Welcome Sanger Institute, Cambridge, CB10 1SA, UK
| | - Jacqueline Smith
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - Richard I Kuo
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - Marilyn B Renfree
- School of Biosciences, The University of Melbourne, Melbourne, VIC, 3052, Australia
| | - Takashi Kimura
- Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0818, Japan
| | - Yoshihiro Sakoda
- Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0818, Japan
| | - Mathew McDougall
- New Zealand Fish & Game - Eastern Region, Rotorua, 3046, New Zealand
| | - Hamish G Spencer
- Department of Zoology, University of Otago, Dunedin, 9054, New Zealand
| | - Michael Pyne
- Currumbin Wildlife Sanctuary, Currumbin, QLD, 4223, Australia
| | - Conny Tolf
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, SE-391 82, Sweden
| | - Jonas Waldenström
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, SE-391 82, Sweden
| | - Erich D Jarvis
- The Vertebrate Genome Laboratory, The Rockefeller University, NY, 10065, USA
| | - Michelle L Baker
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, 5 Portarlington Road, Geelong, VIC, 3220, Australia
| | - David W Burt
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Kirsty R Short
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
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