title: Genomic evolution of MHC class I region in primates.
abstract: To elucidate the origins of the MHC-B-MHC-C pair and the MHC class I chain-related molecule (MIC)A-MICB pair, we sequenced an MHC class I genomic region of humans, chimpanzees, and rhesus monkeys and analyzed the regions from an evolutionary stand-point, focusing first on LINE sequences that are paralogous within each of the first two species and orthologous between them. Because all the long interspersed nuclear element (LINE) sequences were fragmented and nonfunctional, they were suitable for conducting phylogenetic study and, in particular, for estimating evolutionary time. Our study has revealed that MHC-B and MHC-C duplicated 22.3 million years (Myr) ago, and the ape MICA and MICB duplicated 14.1 Myr ago. We then estimated the divergence time of the rhesus monkey by using other orthologous LINE sequences in the class I regions of the three primate species. The result indicates that rhesus monkeys, and possibly the Old World monkeys in general, diverged from humans 27-30 Myr ago. Interestingly, rhesus monkeys were found to have not the pair of MHC-B and MHC-C but many repeated genes similar to MHC-B. These results support our inference that MHC-B and MHC-C duplicated after the divergence between apes and Old World monkeys.
authors.affiliation: RIKEN BioResource Center, RIKEN Tsukuba Institute, Tsukuba 305-0074, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Fukami-Kobayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiina
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Anzai
authors.forename: Kazumi
authors.initials: K
authors.lastname: Sano
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Inoko
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tateno
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D005805:Genes, MHC Class I / Q000235:genetics*; D016678:Genome; D015235:HLA-B Antigens / Q000235:genetics; D015236:HLA-C Antigens / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D020084:Long Interspersed Nucleotide Elements; D008253:Macaca mulatta; D002679:Pan troglodytes; D017434:Protein Structure, Tertiary; D013997:Time Factors
chemical_list: D015235:HLA-B Antigens; D015236:HLA-C Antigens; D015395:Histocompatibility Antigens Class I