title: Characterization of major histocompatibility complex class I loci of the lark sparrow (Chondestes grammacus) and insights into avian MHC evolution.
abstract: The major histocompatibilty complex (MHC) has become increasingly important in the study of the immunocapabilities of non-model vertebrates due to its direct involvement in the immune response. The characterization of MHC class I loci in the lark sparrow (Chondestes grammacus) revealed multiple MHC class I loci with elevated genetic diversity at exon 3, evidence of differential selection between the peptide binding region (PBR) and non-PBR, and the presence of multiple pseudogenes with limited divergence. The minimum number of functional MHC class I loci was estimated at four. Sequence analysis revealed d N /d S ratios significantly less than one at non-PBR sites, indicative of negative selection, whereas PBR sites associated with antigen recognition showed ratios greater than 1 but non-significant. GenBank surveys and phylogenetic analyses of previously reported avian MHC class I sequences revealed variable signatures of evolutionary processes acting upon this gene family, including gene duplication and potential concerted evolution. An increase in the number of class I loci across species coincided with an increase in pseudogene prevalence, revealing the importance of gene duplication in the expansion of multigene families and the creation of pseudogenes.
authors.affiliation: Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, 43403, USA.
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Lyons
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hoostal
authors.forename: Juan L
authors.initials: JL
authors.lastname: Bouzat
mesh_terms: D000483:Alleles; D000818:Animals; D019143:Evolution, Molecular; D020440:Gene Duplication; D056426:Genetic Loci; D014644:Genetic Variation; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D010802:Phylogeny; D046370:Sparrows / Q000235:genetics*
chemical_list: D015395:Histocompatibility Antigens Class I