Sittisombut N, Knight K L
J Immunol. 1986 Mar 1;136(5):1871-5.
Approximately 300 kb of DNA from the rabbit major histocompatibility complex class II region has been cloned from two genomic libraries. Four alpha chain genes and ten beta chain genes were identified in the recombinant phage and cosmid clones by hybridization with human class II cDNA probes. These genes were classified into three subregions (R-DP, R-DQ, and R-DR) based on hybridization analyses with human DP, DQ, and DR subregion genes under stringent conditions. Two alpha genes and one beta gene were assigned to the R-DP subregion, one alpha gene and one beta gene to the R-DQ subregion, and one alpha gene and eight beta genes to the R-DR subregion. In each subregion, the alpha gene and at least one beta gene were closely linked and were oriented in a manner similar to those in the homologous subregions of human and mouse. A combination of cloning data and genomic blot analyses indicated that the rabbit genome contains a minimum of four alpha-chain genes. The results suggested that there has been evolutionary conservation of the subunit organization of the alpha- and beta-chain genes as well as the coding sequences of these genes and that the mammalian ancestor possessed three distinct MHC class II subregions before diversification of human, mouse, and rabbit.
已从两个基因组文库中克隆出约300 kb来自兔主要组织相容性复合体II类区域的DNA。通过与人II类cDNA探针杂交，在重组噬菌体和黏粒克隆中鉴定出四个α链基因和十个β链基因。在严格条件下，根据与人类DP、DQ和DR亚区域基因的杂交分析，这些基因被分为三个亚区域（R-DP、R-DQ和R-DR）。两个α基因和一个β基因被分配到R-DP亚区域，一个α基因和一个β基因被分配到R-DQ亚区域，一个α基因和八个β基因被分配到R-DR亚区域。在每个亚区域中，α基因和至少一个β基因紧密相连，并且其排列方向与人类和小鼠同源亚区域中的基因相似。克隆数据和基因组印迹分析相结合表明，兔基因组至少包含四个α链基因。结果表明，α链和β链基因的亚基组织以及这些基因的编码序列在进化过程中得到了保守，并且在人类、小鼠和兔分化之前，哺乳动物祖先拥有三个不同的MHC II类亚区域。
