Gustafsson K, Widmark E, Jonsson A K, Servenius B, Sachs D H, Larhammar D, Rask L, Peterson P A
J Biol Chem. 1987 Jun 25;262(18):8778-86.
The DP region of the human major histocompatibility complex contains two alpha genes and two beta genes. The DP alpha 1 and beta 1 genes encode the expressed DP histocompatibility antigen molecule, while the DP alpha 2 and beta 2 genes are inactive in the haplotypes examined. Here we present the sequence of the two DP beta genes and of the expressed DP alpha 1 gene. Nucleotide sequence comparisons reveal a considerably greater degree of similarity between the two beta genes than between the two alpha genes. We propose that a duplication giving rise to the DP alpha gene pair evolutionarily preceded the corresponding DP beta gene duplication. We also propose, based on the orientation of other class II gene pairs, that the original DP molecule was encoded by the DP beta 1 and DP alpha 2 genes. At some stage during the evolution of the DP region both of the two pseudogenes appear to have been expressed.
人类主要组织相容性复合体的DP区域包含两个α基因和两个β基因。DPα1和β1基因编码表达的DP组织相容性抗原分子，而DPα2和β2基因在所检测的单倍型中无活性。在此，我们展示了两个DPβ基因以及表达的DPα1基因的序列。核苷酸序列比较显示，两个β基因之间的相似程度明显高于两个α基因之间的相似程度。我们提出，在进化过程中产生DPα基因对的复制先于相应的DPβ基因复制。我们还基于其他II类基因对的方向提出，最初的DP分子由DPβ1和DPα2基因编码。在DP区域进化的某个阶段，这两个假基因似乎都曾被表达。
