title: Extremely high MHC class I variation in a population of a long-distance migrant, the Scarlet Rosefinch (Carpodacus erythrinus).
abstract: Although the number of studies focusing on the major histocompatibility complex (MHC) in non-model vertebrates is increasing, results are often contradictory, and the structure of MHC is still poorly understood in wild species. Here, we describe the structure and diversity of exon 3 of MHC class I in a passerine bird, the Scarlet Rosefinch (Carpodacus erythrinus). Using capillary electrophoresis single-strand conformation polymorphism, we identified 82 different MHC class I variants in one Rosefinch population nesting at one site in the Czech Republic. Thus far, this is the highest intra-populational MHC class I variation observed in birds. We have not found support for 'minimal essential' MHC in this species since individuals exhibited between three and nine different exon 3 sequences, indicating that there may be at least five amplified MHC class I genes. By cloning, we obtained and analysed 29 exon sequences and found that all of them could be translated into potentially functional proteins. We also show that strong positive selection appears to be acting mainly, but not only, on previously described antigen-binding sites in MHC class I genes. Furthermore, our results indicate that recombination has played an important role in generating genetic diversity of these genes in the Scarlet Rosefinch; we discuss the significance of this extremely high genetic diversity in light of the life history traits of this species, such as long-distance migration.
authors.affiliation: Department of Population Biology, Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Studenec 122, 675 02 Konesín, Czech Republic. promerova@seznam.cz
authors.forename: M
authors.initials: M
authors.lastname: Promerová
authors.forename: T
authors.initials: T
authors.lastname: Albrecht
authors.forename: J
authors.initials: J
authors.lastname: Bryja
mesh_terms: D000595:Amino Acid Sequence; D025041:Animal Migration; D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D014644:Genetic Variation; D005828:Genetics, Population; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D015810:Linkage Disequilibrium; D008969:Molecular Sequence Data; D046109:Passeriformes / Q000145:classification / Q000235:genetics* / Q000276:immunology; D018807:Polymorphism, Single-Stranded Conformational; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D015395:Histocompatibility Antigens Class I