Molecular cloning of orangutan and gibbon MHC class I cDNA. The HLA-A and -B loci diverged over 30 million years ago.
To investigate whether the classical HLA MHC class I loci have been preserved during evolution of the primates, we have cloned, sequenced, and expressed eight MHC class I cDNA from orangutan and gibbon lymphocytes. Both the HLA-A and -B loci are present in both of these species. In fact, lymphocytes from the orangutan expressed three HLA-B-related gene products, suggesting that the ancestral homologue of the HLA-B locus had undergone a duplication in this species. Interestingly, several amino acid motifs thought to be important in the Ag-presenting function of MHC class I molecules were preserved in the Ag-recognition sites of the orangutan and gibbon MHC class I molecules. Finally, these findings suggest that the recombination event between the HLA-A and -E loci occurred over 38 million years ago. These data indicate that the HLA-A and -B loci are extremely stable and that recombination between them is rare. Furthermore, the data presented here argue against the role of concerted evolution in the evolution of primate MHC class I molecules.
Chen
Z W
ZW
Harvard Medical School, New England Regional Primate Research Center, Southborough, MA 01772.
McAdam
S N
SN
Hughes
A L
AL
Dogon
A L
AL
Letvin
N L
NL
Watkins
D I
DI
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification*; D005805:Genes, MHC Class I; D015234:HLA-A Antigens / Q000235:genetics*; D015235:HLA-B Antigens / Q000235:genetics*; D006922:Hylobates / Q000276:immunology*; D008969:Molecular Sequence Data; D011148:Pongo pygmaeus / Q000276:immunology*; D011995:Recombination, Genetic
D015234:HLA-A Antigens; D015235:HLA-B Antigens; D004247:DNA