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Day G, Robb K, Oxley A, Telonis-Scott M, Ujvari B. Organisation and evolution of the major histocompatibility complex class I genes in cetaceans. iScience 2024; 27:109590. [PMID: 38632986 PMCID: PMC11022044 DOI: 10.1016/j.isci.2024.109590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/30/2023] [Accepted: 03/25/2024] [Indexed: 04/19/2024] Open
Abstract
A quarter of marine mammals are at risk of extinction, with disease and poor habitat quality contributing to population decline. Investigation of the Major Histocompatibility Complex (MHC) provides insight into species' capacity to respond to immune and environmental challenges. The eighteen available cetacean chromosome level genomes were used to annotate MHC Class I loci, and to reconstruct the phylogenetic relationship of the described loci. The highest number of loci was observed in the striped dolphin (Stenella coeruleoalba), while the least was observed in the pygmy sperm whale (Kogia breviceps) and rough toothed dolphin (Steno bredanensis). Of the species studied, Mysticetes had the most pseudogenes. Evolutionarily, MHC Class I diverged before the speciation of cetaceans. Yet, locus one was genomically and phylogenetically similar in many species, persisting over evolutionary time. This characterisation of MHC Class I in cetaceans lays the groundwork for future population genetics and MHC expression studies.
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Affiliation(s)
- Grace Day
- School of Life and Environmental Sciences, Deakin University, Geelong 3216, VIC, Australia
- Marine Mammal Foundation, Melbourne 3194, VIC, Australia
| | - Kate Robb
- Marine Mammal Foundation, Melbourne 3194, VIC, Australia
| | - Andrew Oxley
- School of Life and Environmental Sciences, Deakin University, Geelong 3216, VIC, Australia
| | - Marina Telonis-Scott
- School of Life and Environmental Sciences, Deakin University, Melbourne 3125, VIC, Australia
| | - Beata Ujvari
- School of Life and Environmental Sciences, Deakin University, Geelong 3216, VIC, Australia
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Arbanasić H, Medrano-González L, Hrenar T, Mikelić A, Gomerčić T, Svetličić I, Pavlinec Ž, Đuras M, Galov A. Recent selection created distinctive variability patterns on MHC class II loci in three dolphin species from the Mediterranean Sea. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 150:105079. [PMID: 37832898 DOI: 10.1016/j.dci.2023.105079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023]
Abstract
The major histocompatibility complex (MHC) includes highly polymorphic genes involved in antigen presentation, which is crucial for adaptive immune response. They represent fitness related genetic markers particularly informative for populations exposed to environmental challenges. Here we analyse the diversity and evolutionary traits of MHC class II DQA and DQB genes in the dolphins Stenella coeruleoalba and Grampus griseus from the Mediterranean Sea. We found substantial nucleotide and functional diversity, as well as strong evidence of balancing selection indicated by allele and supertype frequencies, Tajima's D statistics and dN/dS tests. The Risso's dolphin, considered the least abundant in the region, showed the effect of divergent allele advantage at the nucleotide and functional-peptide levels. An outstanding polymorphism was found in the striped dolphin, particularly intriguing in the DQA gene where the Ewens-Watterson test detected a selection sweep that occurred in recent history. We hypothesize that morbillivirus, which has recurrently invaded Mediterranean populations over the last decades, exerted the detected selective pressure.
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Affiliation(s)
- Haidi Arbanasić
- Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia.
| | - Luis Medrano-González
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, 04510, Mexico.
| | - Tomica Hrenar
- Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia.
| | - Ana Mikelić
- Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia.
| | - Tomislav Gomerčić
- Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000, Zagreb, Croatia.
| | - Ida Svetličić
- Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia.
| | - Željko Pavlinec
- Croatian Academy of Sciences and Arts, Trg Nikole Šubića Zrinskog 11, 10000, Zagreb, Croatia.
| | - Martina Đuras
- Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000, Zagreb, Croatia.
| | - Ana Galov
- Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia.
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Sá ALAD, Baker PKB, Breaux B, Oliveira JM, Klautau AGCDM, Legatzki K, Luna FDO, Attademo FLN, Hunter ME, Criscitiello MF, Schneider MPC, Sena LDS. Novel insights on aquatic mammal MHC evolution: Evidence from manatee DQB diversity. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 132:104398. [PMID: 35307479 DOI: 10.1016/j.dci.2022.104398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/14/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
The low diversity in marine mammal major histocompatibility complex (MHC) appears to support the hypothesis of reduced pathogen selective pressure in aquatic systems compared to terrestrial environments. However, the lack of characterization of the aquatic and evolutionarily distant Sirenia precludes drawing more generalized conclusions. Therefore, we aimed to characterize the MHC DQB diversity of two manatee species and compare it with those reported for marine mammals. Our results identified 12 and 6 alleles in T. inunguis and T. manatus, respectively. Alleles show high rates of nonsynonymous substitutions, suggesting loci are evolving under positive selection. Among aquatic mammals, Pinnipeda DQB had smaller numbers of alleles, higher synonymous substitution rate, and a dN/dS ratio closer to 1, suggesting it may be evolving under more relaxed selection compared to fully aquatic mammals. This contradicts one of the predictions of the hypothesis that aquatic environments impose reduced pathogen pressure to mammalian immune system. These results suggest that the unique evolutionary trajectories of mammalian MHC may impose challenges in drawing ecoevolutionary conclusions from comparisons across distant vertebrate lineages.
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Affiliation(s)
- André Luiz Alves de Sá
- Laboratory of Applied Genetics (LGA), Socio-Environmental and Water Resources Institute (ISARH), Federal Rural University of the Amazon (UFRA), Av. Presidente Tancredo Neves 2501, 66077-830, Belém, PA, Brazil; Laboratory of Genomics and Biotechnology, Biological Sciences Institute, Federal University of Pará (UFPA), R. Augusto Correa 01, 66075-110, Belém, PA, Brazil.
| | - Pamela Ketrya Barreiros Baker
- Laboratory of Genomics and Biotechnology, Biological Sciences Institute, Federal University of Pará (UFPA), R. Augusto Correa 01, 66075-110, Belém, PA, Brazil
| | - Breanna Breaux
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Jairo Moura Oliveira
- Zoological Park of Santarém - Universidade da Amazônia (ZOOUNAMA), R. Belo Horizonte, 68030-150, Santarém, PA, Brazil
| | - Alex Garcia Cavalleiro de Macedo Klautau
- Centro Nacional de Pesquisa e Conservação da Biodiversidade Marinha do Norte (CEPNOR), Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), Av. Presidente Tancredo Neves 2501, 66077-830, Belém, PA, Brazil
| | - Kristian Legatzki
- Centro Nacional de Pesquisa e Conservação da Biodiversidade Marinha do Norte (CEPNOR), Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), Av. Presidente Tancredo Neves 2501, 66077-830, Belém, PA, Brazil
| | - Fábia de Oliveira Luna
- National Center for Research and Conservation of Aquatic Mammals, Chico Mendes Institute for Biodiversity Conservation (CMA), ICMBio, Rua Alexandre Herculano 197, 11050-031, Santos, SP, Brazil
| | - Fernanda Löffler Niemeyer Attademo
- National Center for Research and Conservation of Aquatic Mammals, Chico Mendes Institute for Biodiversity Conservation (CMA), ICMBio, Rua Alexandre Herculano 197, 11050-031, Santos, SP, Brazil
| | - Margaret Elizabeth Hunter
- U.S. Geological Survey, Wetland and Aquatic Research Center, 7920 NW 71st Street, Gainesville, FL, 32653, USA.
| | - Michael Frederick Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA.
| | - Maria Paula Cruz Schneider
- Laboratory of Genomics and Biotechnology, Biological Sciences Institute, Federal University of Pará (UFPA), R. Augusto Correa 01, 66075-110, Belém, PA, Brazil.
| | - Leonardo Dos Santos Sena
- Center for Advanced Biodiversity Studies (CEABIO), Biological Sciences Institute, Federal University of Pará (UFPA), R. Augusto Correa 01, 66075-110, Belém, PA, Brazil.
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Klumplerova M, Splichalova P, Oppelt J, Futas J, Kohutova A, Musilova P, Kubickova S, Vodicka R, Orlando L, Horin P. Genetic diversity, evolution and selection in the major histocompatibility complex DRB and DQB loci in the family Equidae. BMC Genomics 2020; 21:677. [PMID: 32998693 PMCID: PMC7525986 DOI: 10.1186/s12864-020-07089-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 09/21/2020] [Indexed: 02/08/2023] Open
Abstract
Background The mammalian Major Histocompatibility Complex (MHC) is a genetic region containing highly polymorphic genes with immunological functions. MHC class I and class II genes encode antigen-presenting molecules expressed on the cell surface. The MHC class II sub-region contains genes expressed in antigen presenting cells. The antigen binding site is encoded by the second exon of genes encoding antigen presenting molecules. The exon 2 sequences of these MHC genes have evolved under the selective pressure of pathogens. Interspecific differences can be observed in the class II sub-region. The family Equidae includes a variety of domesticated, and free-ranging species inhabiting a range of habitats exposed to different pathogens and represents a model for studying this important part of the immunogenome. While equine MHC class II DRA and DQA loci have received attention, the genetic diversity and effects of selection on DRB and DQB loci have been largely overlooked. This study aimed to provide the first in-depth analysis of the MHC class II DRB and DQB loci in the Equidae family. Results Three DRB and two DQB genes were identified in the genomes of all equids. The genes DRB2, DRB3 and DQB3 showed high sequence conservation, while polymorphisms were more frequent at DRB1 and DQB1 across all species analyzed. DQB2 was not found in the genome of the Asiatic asses Equus hemionus kulan and E. h. onager. The bioinformatic analysis of non-zero-coverage-bases of DRB and DQB genes in 14 equine individual genomes revealed differences among individual genes. Evidence for recombination was found for DRB1, DRB2, DQB1 and DQB2 genes. Trans-species allele sharing was identified in all genes except DRB1. Site-specific selection analysis predicted genes evolving under positive selection both at DRB and DQB loci. No selected amino acid sites were identified in DQB3. Conclusions The organization of the MHC class II sub-region of equids is similar across all species of the family. Genomic sequences, along with phylogenetic trees suggesting effects of selection as well as trans-species polymorphism support the contention that pathogen-driven positive selection has shaped the MHC class II DRB/DQB sub-regions in the Equidae.
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Affiliation(s)
- Marie Klumplerova
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic
| | - Petra Splichalova
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic
| | - Jan Oppelt
- Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic.,Ceitec MU, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic.,National Centre for Biomolecular research, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Jan Futas
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic
| | - Aneta Kohutova
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Petra Musilova
- Department of Genetics and Reproductive Biotechnologies, Veterinary Research Institute, Brno, Czech Republic.,Ceitec VRI, RG Animal Cytogenomics, Brno, Czech Republic
| | - Svatava Kubickova
- Department of Genetics and Reproductive Biotechnologies, Veterinary Research Institute, Brno, Czech Republic.,Ceitec VRI, RG Animal Cytogenomics, Brno, Czech Republic
| | - Roman Vodicka
- Zoo Prague, U Trojského zámku 120/3, 171 00, Praha 7, Czech Republic
| | - Ludovic Orlando
- Laboratoire d'Anthropobiologie Moléculaire et d'Imagerie de Synthèse, CNRS UMR 5288, Université de Toulouse, Université Paul Sabatier, 31000, Toulouse, France.,Centre for GeoGenetics, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350K, Copenhagen, Denmark
| | - Petr Horin
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic. .,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic.
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Latitudinal diversity gradient and cetaceans from the perspective of MHC genes. Immunogenetics 2020; 72:393-398. [PMID: 32564115 DOI: 10.1007/s00251-020-01171-9] [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: 12/17/2019] [Accepted: 06/05/2020] [Indexed: 01/07/2023]
Abstract
Pathogen diversity is a key source of selective pressure on immune system genes, shaping molecular evolution mainly on widely distributed or migratory organisms such as cetaceans. Here, we investigated the effects of latitudinal span migration, different biomes occupation, and pathogen-mediated selection on MHC DQB locus divergence on cetaceans. We applied some evolutionary genetics methods using a dataset of 15 species and 121 sequences, and we found a trend on greater MHC divergence on tropical species when compared with either temperate or migratory species. In addition, oceanic cetaceans exhibit greater MHC divergence. Here, we show that, despite there was a correlation between the diversity of MHC DQB alleles with the distribution of organisms, the pattern of diversity found is not completely explained by pathogenic pressure, suggesting that other factors must be investigated for a better understanding of the processes related to the diversity of MHC in cetaceans.
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de Sá ALA, Breaux B, Burlamaqui TCT, Deiss TC, Sena L, Criscitiello MF, Schneider MPC. The Marine Mammal Class II Major Histocompatibility Complex Organization. Front Immunol 2019; 10:696. [PMID: 31019512 PMCID: PMC6459222 DOI: 10.3389/fimmu.2019.00696] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/13/2019] [Indexed: 12/17/2022] Open
Abstract
Sirenians share with cetaceans and pinnipeds several convergent traits selected for the aquatic lifestyle. Living in water poses new challenges not only for locomotion and feeding but also for combating new pathogens, which may render the immune system one of the best tools aquatic mammals have for dealing with aquatic microbial threats. So far, only cetaceans have had their class II Major Histocompatibility Complex (MHC) organization characterized, despite the importance of MHC genes for adaptive immune responses. This study aims to characterize the organization of the marine mammal class II MHC using publicly available genomes. We located class II sequences in the genomes of one sirenian, four pinnipeds and eight cetaceans using NCBI-BLAST and reannotated the sequences using local BLAST search with exon and intron libraries. Scaffolds containing class II sequences were compared using dotplot analysis and introns were used for phylogenetic analysis. The manatee class II region shares overall synteny with other mammals, however most DR loci were translocated from the canonical location, past the extended class II region. Detailed analysis of the genomes of closely related taxa revealed that this presumed translocation is shared with all other living afrotherians. Other presumptive chromosome rearrangements in Afrotheria are the deletion of DQ loci in Afrosoricida and deletion of DP in E. telfairi. Pinnipeds share the main features of dog MHC: lack of a functional pair of DPA/DPB genes and inverted DRB locus between DQ and DO subregions. All cetaceans share the Cetartiodactyla inversion separating class II genes into two subregions: class IIa, with DR and DQ genes, and class IIb, with non-classic genes and a DRB pseudogene. These results point to three distinct and unheralded class II MHC structures in marine mammals: one canonical organization but lacking DP genes in pinnipeds; one bearing an inversion separating IIa and IIb subregions lacking DP genes found in cetaceans; and one with a translocation separating the most diverse class II gene from the MHC found in afrotherians and presumptive functional DR, DQ, and DP genes. Future functional research will reveal how these aquatic mammals cope with pathogen pressures with these divergent MHC organizations.
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Affiliation(s)
- André Luiz Alves de Sá
- Laboratory of Applied Genetics, Socio-Environmental and Water Resources Institute, Federal Rural University of the Amazon, Belém, Brazil.,Laboratory of Genomics and Biotechnology, Biological Sciences Institute, Federal University of Pará, Belém, Brazil
| | - Breanna Breaux
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | | | - Thaddeus Charles Deiss
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Leonardo Sena
- Center of Biodiversity Advanced Studies, Biological Sciences Institute, Federal University of Pará, Belém, Brazil
| | - Michael Frederick Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Maria Paula Cruz Schneider
- Laboratory of Genomics and Biotechnology, Biological Sciences Institute, Federal University of Pará, Belém, Brazil
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Dooley CT, Ferrer T, Pagán H, O’Corry-Crowe GM. Bridging immunogenetics and immunoproteomics: Model positional scanning library analysis for Major Histocompatibility Complex class II DQ in Tursiops truncatus. PLoS One 2018; 13:e0201299. [PMID: 30070993 PMCID: PMC6072028 DOI: 10.1371/journal.pone.0201299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 07/12/2018] [Indexed: 02/02/2023] Open
Abstract
The Major Histocompatibility Complex (MHC) is a critical element in mounting an effective immune response in vertebrates against invading pathogens. Studies of MHC in wildlife populations have typically focused on assessing diversity within the peptide binding regions (PBR) of the MHC class II (MHC II) family, especially the DQ receptor genes. Such metrics of diversity, however, are of limited use to health risk assessment since functional analyses (where changes in the PBR are correlated to recognition/pathologies of known pathogen proteins), are difficult to conduct in wildlife species. Here we describe a means to predict the binding preferences of MHC proteins: We have developed a model positional scanning library analysis (MPSLA) by harnessing the power of mixture based combinatorial libraries to probe the peptide landscapes of distinct MHC II DQ proteins. The algorithm provided by NNAlign was employed to predict the binding affinities of sets of peptides generated for DQ proteins. These binding affinities were then used to retroactively construct a model Positional Scanning Library screen. To test the utility of the approach, a model screen was compared to physical combinatorial screens for human MHC II DP. Model library screens were generated for DQ proteins derived from sequence data from bottlenose dolphins from the Indian River Lagoon (IRL) and the Atlantic coast of Florida, and compared to screens of DQ proteins from Genbank for dolphin and three other cetaceans. To explore the peptide binding landscape for DQ proteins from the IRL, combinations of the amino acids identified as active were compiled into peptide sequence lists that were used to mine databases for representation in known proteins. The frequency of which peptide sequences predicted to bind the MHC protein are found in proteins from pathogens associated with marine mammals was found to be significant (p values <0.0001). Through this analysis, genetic variation in MHC (classes I and II) can now be associated with the binding repertoires of the expressed MHC proteins and subsequently used to identify target pathogens. This approach may be eventually applied to evaluate individual population and species risk for outbreaks of emerging diseases.
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Affiliation(s)
- Colette T. Dooley
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida, United States of America
| | - Tatiana Ferrer
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, United States of America
| | - Heidi Pagán
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, United States of America
| | - Gregory M. O’Corry-Crowe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, United States of America
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Lau Q, Chow N, Gray R, Gongora J, Higgins DP. Diversity of MHCDQBandDRBGenes in the Endangered Australian Sea Lion (Neophoca cinerea). J Hered 2015; 106:395-402. [DOI: 10.1093/jhered/esv022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/25/2015] [Indexed: 01/26/2023] Open
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Cammen KM, Wilcox LA, Rosel PE, Wells RS, Read AJ. From genome-wide to candidate gene: an investigation of variation at the major histocompatibility complex in common bottlenose dolphins exposed to harmful algal blooms. Immunogenetics 2014; 67:125-33. [DOI: 10.1007/s00251-014-0818-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 11/24/2014] [Indexed: 01/24/2023]
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10
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Spatial variation and low diversity in the major histocompatibility complex in walrus (Odobenus rosmarus). Polar Biol 2014. [DOI: 10.1007/s00300-014-1450-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Gillett RM, Murray BW, White BN. Characterization of class I- and class II-like major histocompatibility complex loci in pedigrees of North Atlantic right whales. J Hered 2013; 105:188-202. [PMID: 24381183 DOI: 10.1093/jhered/est095] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
North Atlantic right whales have one of the lowest levels of genetic variation at minisatellite loci, microsatellite loci, and mitochondrial control region haplotypes among mammals. Here, adaptive variation at the peptide binding region of class I and class II DRB-like genes of the major histocompatibility complex was assessed. Amplification of a duplicated region in 222 individuals revealed at least 11 class II alleles. Six alleles were assigned to the locus Eugl-DRB1 and 5 alleles were assigned to the locus Eugl-DRB2 by assessing segregation patterns of alleles from 81 parent/offspring pedigrees. Pedigree analysis indicated that these alleles segregated into 12 distinct haplotypes. Genotyping a smaller subset of unrelated individuals (n = 5 and 10, respectively) using different primer sets revealed at least 2 class II pseudogenes (with ≥ 4 alleles) and at least 3 class I loci (with ≥ 6 alleles). Class II sequences were significantly different from neutrality at peptide binding sites suggesting loci may be under the influence of balancing selection. Trans-species sharing of alleles was apparent for class I and class II sequences. Characterization of class II loci represents the first step in determining the relationship between major histocompatibility complex variability and factors affecting health and reproduction in this species.
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Affiliation(s)
- Roxanne M Gillett
- the Natural Resources DNA Profiling and Forensic Centre, Department of Biology, Trent University, 2140 East Bank Drive, Peterborough, Ontario K9J 7B8, Canada
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