title: Polymorphism and selection in the major histocompatibility complex DRA and DQA genes in the family Equidae.
abstract: The major histocompatibility complex genes coding for antigen binding and presenting molecules are the most polymorphic genes in the vertebrate genome. We studied the DRA and DQA gene polymorphism of the family Equidae. In addition to 11 previously reported DRA and 24 DQA alleles, six new DRA sequences and 13 new DQA alleles were identified in the genus Equus. Phylogenetic analysis of both DRA and DQA sequences provided evidence for trans-species polymorphism in the family Equidae. The phylogenetic trees differed from species relationships defined by standard taxonomy of Equidae and from trees based on mitochondrial or neutral gene sequence data. Analysis of selection showed differences between the less variable DRA and more variable DQA genes. DRA alleles were more often shared by more species. The DQA sequences analysed showed strong amongst-species positive selection; the selected amino acid positions mostly corresponded to selected positions in rodent and human DQA genes.
authors: Institute of Animal Genetics, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic.
authors: Eva
authors: E
authors: Janova
authors: Jan
authors: J
authors: Matiasovic
authors: Jiri
authors: J
authors: Vahala
authors: Roman
authors: R
authors: Vodicka
authors: Enette
authors: E
authors: Van Dyk
authors: Petr
authors: P
authors: Horin
mesh_terms: D000483:Alleles; D000818:Animals; D001483:Base Sequence; D018153:Czech Republic; D004247:DNA / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D018397:Equidae / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D019143:Evolution, Molecular; D014644:Genetic Variation; D006736:Horses / Q000235:genetics / Q000276:immunology; D055261:Immunogenetic Phenomena; D008285:Major Histocompatibility Complex; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D012641:Selection, Genetic; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D004247:DNA