Class I MHC expression in the yellow baboon.
MHC class I molecules play a crucial role in the immune response to pathogens and vaccines and in self/non-self recognition. Therefore, characterization of MHC class I gene expression of Papio subspecies is a prerequisite for studies of immunology and transplantation in the baboon (papio hamadryas). To elucidate MHC class I expression and variation within Papio subspecies and to further investigate the evolution of A and B loci in Old World primates, we have characterized the expressed class I repertoire of the yellow baboon (Papio hamadryas cynocephalus) by cDNA library screening. A total of nine distinct MHC class I cDNAs were isolated from a spleen cDNA library. The four A alleles and four B alleles obtained represent four distinct loci indicating that a duplication of the A and B loci has taken place in the lineage leading to these Old World primates. No HLA--C homologue/orthologue was found. In addition a single, nonclassical homologue of HLA--E was characterized. Examination of nucleotide and extrapolated protein sequences indicates that alleles at the two B loci are much more diversified than the alleles at the A loci. One of the A loci in particular appears to display very limited polymorphism in both Papio hamadryas cynocephalus and Papio hamadryas anubis subspecies. The failure to detect a homologue of HLA--C in the baboon provides additional evidence for the more recent origin of this locus in the pongidae and hominidae: Further comparative analysis with MHC sequences among the primate species reveals specific patterns of divergence and conservation within class I molecules of the yellow baboon.
Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190, USA.
D A
DA
Sidebottom
R
R
Kennedy
W H
WH
Hildebrand
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D002521:Cercopithecus; D018076:DNA, Complementary / Q000302:isolation & purification; D005786:Gene Expression Regulation / Q000276:immunology*; D015723:Gene Library; D005805:Genes, MHC Class I; D005819:Genetic Markers / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D008253:Macaca mulatta; D008297:Male; D008969:Molecular Sequence Data; D010215:Papio / Q000235:genetics* / Q000276:immunology*; D010455:Peptides / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D010802:Phylogeny; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D013154:Spleen / Q000276:immunology / Q000378:metabolism
D018076:DNA, Complementary; D005819:Genetic Markers; D015395:Histocompatibility Antigens Class I; D010455:Peptides