title: A major histocompatibility complex class I allele shared by two species of chimpanzee.
abstract: Little is known regarding the rates at which natural selection can modify or retain antigen presenting alleles at the major histocompatibility complex (MHC). Discovery of identical [1101 base pairs (bp)] coding regions at the MHC class I C locus in Pan troglodytes and Pan paniscus, chimpanzee species that diverged approximately 2.3 million years ago, now indicates that a class I allotype can survive for at least this period. Remarkable conservation was also reflected in the (1799 bp) introns where a maximum of only six substitutions distinguished five alleles (three from P. troglodytes and two from P. paniscus) that encoded the identical heavy chain allotype. Analysis of a more distantly related human allele, HLA-Cw*0702, corroborated that intron variation was non-uniform along the gene. Thus we provide a clear reference frame for the lifetime of an MHC class I allotype, a direct estimate of allelic substitution rates, and evidence for an unusual evolution of MHC class I introns.
authors.affiliation: Department of Structural Biology, Sherman Fairchild Building, Stanford University School of Medicine, Stanford, CA 94305-5400, USA.
authors.forename: S
authors.initials: S
authors.lastname: Cooper
authors.forename: E J
authors.initials: EJ
authors.lastname: Adams
authors.forename: R S
authors.initials: RS
authors.lastname: Wells
authors.forename: C M
authors.initials: CM
authors.lastname: Walker
authors.forename: P
authors.initials: P
authors.lastname: Parham
mesh_terms: D000483:Alleles; D000818:Animals; D001483:Base Sequence; D002461:Cell Line, Transformed; D018076:DNA, Complementary; D005805:Genes, MHC Class I; D006801:Humans; D008969:Molecular Sequence Data; D002679:Pan troglodytes / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny
chemical_list: D018076:DNA, Complementary