Gyllensten U, Sundvall M, Ezcurra I, Erlich H A
Department of Medical Genetics, University of Uppsala, Sweden.
J Immunol. 1991 Jun 15;146(12):4368-76.
The evolution of polymorphism at loci encoding the beta-chains of the MHC class II DR Ag was studied in primates by DNA amplification (polymerase chain reaction). Phylogenetic analysis of 63 DRB sequences from the polymorphic second exon (first domain) of nonhuman primates and 53 human sequences indicates the presence of five DRB loci in primates, derived from a DRB1-like ancestral locus over 20 million yr ago. Many of the allelic types at the DRB1 locus predate the divergence of hominoids (5 million yr ago) and some (DR4, DR3, 5, 6) predate the divergence of Old world monkeys and hominoids (20 million yr ago). The DRB3 locus appears to have arisen before the divergence of hominoids on an ancestral DRB1 lineage. The DRB2 and DRB5 loci were generated more than 20 million yr ago and the DRB4 locus more than 5 million yr ago. The DRB2 locus, a pseudogene in humans, is polymorphic in the nonhuman primates.
通过DNA扩增（聚合酶链反应）研究了灵长类动物中编码MHC II类DR抗原β链的基因座上多态性的演变。对来自非人类灵长类动物多态性第二外显子（第一结构域）的63个DRB序列和53个人类序列进行系统发育分析表明，灵长类动物中存在五个DRB基因座，它们起源于2000多万年前一个类似DRB1的祖先基因座。DRB1基因座的许多等位基因类型早于类人猿的分化（500万年前），有些（DR4、DR3、5、6）早于旧世界猴和类人猿的分化（2000万年前）。DRB3基因座似乎是在类人猿分化之前在一个祖先DRB1谱系上出现的。DRB2和DRB5基因座在2000多万年前产生，DRB4基因座在500多万年前产生。DRB2基因座在人类中是一个假基因，在非人类灵长类动物中具有多态性。
