Segmental exchange between MHC class I genes in a higher primate: recombination in the gorilla between the ancestor of a human non-functional gene and an A locus gene.
Classical human major histocompatibility complex (MHC) class I molecules are the products of highly diverse gene loci. It has been suggested that segmental exchange may play a role in the generation of diversity at the antigen recognition site of MHC class I molecules. Here we present the cloning, sequencing and expression of two gorilla A locus cDNAs. One of these cDNAs shows remarkable similarity to the non-functional HLA-AR locus gene (5.4-LBF) only in exon 2. The remainder of the cDNA, however, is most closely related to other classical higher primate A locus genes. This suggests that a segmental exchange may have occurred between the ancestor of the non-functional HLA-AR gene and a classical gorilla A locus gene. Furthermore, the recombination event resulting in Gogo-A3 has affected its antigen recognition site. These data, therefore, demonstrate that segmental exchange can generate diversity at the antigen recognition sites of primate MHC class I molecules and suggest that non-functional genes can contribute to the generation of diversity of classical MHC class I genes.
Watkins
D I
DI
Harvard Medical School, New England Regional Primate Research Center, Southborough, MA 01772.
Chen
Z W
ZW
Garber
T L
TL
Hughes
A L
AL
Letvin
N L
NL
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D005805:Genes, MHC Class I; D014644:Genetic Variation; D006071:Gorilla gorilla / Q000235:genetics*; D008969:Molecular Sequence Data; D011995:Recombination, Genetic