Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q3V6T2 (ape)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DRB region of the human and great-ape major histocompatibility complex displays not only gene but also haplotype polymorphism. The number of genes in the human DRB region can vary from one to four, and even greater variability exists among the DRB haplotypes of chimpanzees, gorillas, and orangutans. Accumulating evidence indicates that, like gene polymorphism, part of the haplotype polymorphism predates speciation. In an effort to determine when the gene haplotype polymorphisms emerged in the primate lineage, we sequenced three cDNA clones of the New-World monkey, the cottontop tamarin (Saguinus oedipus). We could identify two DRB loci in this species, one (Saoe-DRB1) occupied by apparently functional alleles (*0101 and *0102) which differ by only two nucleotide substitutions and the other (Saoe-DRB2) occupied by an apparent pseudogene. The Saoe-DRB2 gene contains an extra sequence derived from the 3' portion of exon 2 and placed 5' to this exon. This sequence contains a stop codon which makes the translation of the bulk of the Saoe-DRB2 gene unlikely. Preliminary Southern blot hybridization analysis with probes derived from these two genes suggests that both the DRB gene polymorphism and the haplotype polymorphism in the cottontop tamarin may be low. In most individuals the DRB region of this species probably consists of three genes. Comparisons of the Saoe-DRB sequences with those of other primates suggest that probably all of the DRB genes found until now in the Catarrhini were derived from a common ancestor after the separation of the Catarrhini and Platyrrhini lineages. The extant DRB gene and haplotype polymorphism may therefore have been founded in the mid-Oligocene some 33 Mya.
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PMID:Major-histocompatibility-complex DRB genes of a New-World monkey, the cottontop tamarin (Saguinus oedipus). 158 11

The DRB family of human class II major histocompatibility complex (Mhc) loci is unusual in that individuals differ in the number and combination of genes (haplotypes) they carry. Indications are that both the allelic and haplotype polymorphisms of the DRB loci predate speciation. Searching for the evolutionary origins of these polymorphisms, we have sequenced five DRB clones isolated from a cDNA library of a pigtail macaque (Macaca nemestrina) B lymphocyte line. The clones represent five different genes which we designate Mane-DRB*01-Mane-DRB*05. The genes appears to be approximately equidistant from each other, so that allelic relationships between them cannot be established on the basis of the sequence data alone. If positions coding for the peptide-binding region of the class II beta chains are eliminated from sequence comparisons, the Mane-DRB genes appear to be most closely related to the human (HLA) DRB1 genes of the DRw52 group. We interpret this finding to indicate that the ancestral gene of the DRw52 group of human DRB1 alleles separated from the rest of the HLA-DRB1 alleles before the separation of the Old World monkeys (Cercopithecoidea) from the apes (Hominoidea) in the early Oligocene. After this separation, the ancestral DRB1 gene of the DRw52 group duplicated in the Old World monkey lineage to give rise to genes at three loci at least, while in the ape lineage this gene may have remained single and diverged into a number of alleles instead. These findings suggest that some of the polymorphism currently present at the DRB1 locus is greater than 35 Myr old.
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PMID:Mhc-DRB genes of the pigtail macaque (Macaca nemestrina): implications for the evolution of human DRB genes. 176 59

The DRB subregion of the HLA complex contains, in addition to the functional genes, a number of pseudogenes and gene fragments. Fourteen kilobases of DNA were sequenced from the segment upstream of the DRB9 gene fragment, as well as shorter segments from different HLA and corresponding ape haplotypes. The analysis of the sequences and restriction fragments indicates that the segment is a remnant of an ancient DRB subregion which may have been functional before the primate radiation and which later became the source of extant functional DRB genes in various primate groups, different ones in different groups. The remnant segment has remained constant in its organization for at least 4 million years. This constancy contrasts with the variability of the adjacent functional part of the DRB subregion occupied by the DRB1 and other loci. The constancy may be related to the monomorphism and evolutionary conservation of the DRA locus.
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PMID:HLA-DRB9--possible remnant of an ancient functional DRB subregion. 916 94