title: Evolutionary relationships of major histocompatibility complex class I genes in simian primates.
abstract: New World monkeys (NWMs) occupy a critical phylogenetic position in elucidating the evolutionary process of major histocompatibility complex (MHC) class I genes in primates. From three subfamilies of Aotinae, Cebinae, and Atelinae, the 5'-flanking regions of 18 class I genes are obtained and phylogenetically examined in terms of Alu/LINE insertion elements as well as the nucleotide substitutions. Two pairs of genes from Aotinae and Atelinae are clearly orthologous to human leukocyte antigen (HLA) -E and -F genes. Of the remaining 14 genes, 8 belong to the distinct group B, together with HLA-B and -C, to the exclusion of all other HLA class I genes. These NWM genes are classified into four groups, designated as NWM-B1, -B2, -B3, and -B4. Of these, NWM-B2 is orthologous to HLA-B/C. Also, orthologous relationships of NWM-B1, -B2, and -B3 exist among different families of Cebidae and Atelidae, which is in sharp contrast to the genus-specific gene organization within the subfamily Callitrichinae. The other six genes belong to the distinct group G. However, a clade of these NWM genes is almost equally related to HLA-A, -J, -G, and -K, and there is no evidence for their orthologous relationships to HLA-G. It is argued that class I genes in simian primates duplicated extensively in their common ancestral lineage and that subsequent evolution in descendant species has been facilitated mainly by independent loss of genes.
authors.affiliation: Department of Biosystems Science, Graduate University for Advanced Studies (Sokendai), Hayama, Kanagawa 240-0193, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sawai
authors.forename: Yoshi
authors.initials: Y
authors.lastname: Kawamoto
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Takahata
authors.forename: Yoko
authors.initials: Y
authors.lastname: Satta
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D002427:Cebidae / Q000235:genetics*; D016000:Cluster Analysis; D017931:DNA Primers; D019143:Evolution, Molecular; D005805:Genes, MHC Class I / Q000235:genetics*; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D017931:DNA Primers