POLYMORPHISM OF HUMAN IA ANTIGENS - GENE CONVERSION BETWEEN 2 DR-BETA LOCI RESULTS IN A NEW HLA-D/DR SPECIFICITY
POLYMORPHISM OF HUMAN IA ANTIGENS - GENE CONVERSION BETWEEN 2 DR-BETA LOCI RESULTS IN A NEW HLA-D/DR SPECIFICITY
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DOI：
10.1038/322067a0
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发表时间：
1986-07-03
期刊：
影响因子：
64.8
通讯作者：
MACH, B
中科院分区：
文献类型：
--
作者：
GORSKI, J;MACH, B
人类主要组织相容性复合体（MHC）中的多态性HLA-DRβ链由基因重复产生的多个位点编码。基于共有的结构因子，可将CDR单倍型分组为家族。我们研究了HLA-DR单倍型DR 3、DR 5和DRw 6的分子基础。DRβ链区域的分子定位允许两个表达的DRβ链基因座DRβ I和DR βIII的真实等位基因比较。在多态性更强的位点DRβI，等位基因差异聚集在一起，可能是由很短距离内的基因转换事件引起的。HLA-DR β 3/Dw 3特异性基因是通过将HLA-DR β 6/Dw 18单倍型的DR β I和DR β III位点分别作为受体和供体基因进行基因转换而产生的。根据在DR βIII（多态性较低的位点）上发现的等位基因，可以定义两组单倍型：DRw 52 a和DRw 52 b。DRw 52超型组内HLA-DR多态性的产生是由一系列的基因重复、趋异和基因转换引起的。
The polymorphic HLA-DRβ-chains are encoded within the human major histocompatibility complex (MHC) by multiple loci resulting from gene duplications. CertainDRhaplotypes can be grouped into families based on shared structural factors. We have studied the molecular basis of HLA-DR polymorphism within such a group which includes the haplotypesDR3,DR5andDRw6. Molecular mapping of the DRβ-chain region allows true allelic comparisons of the two expressed DRβ-chain loci,DRβIandDRβIII. At the more polymorphic locus,DRβI, the allelic differences are clustered and may result from gene conversion events over very short distances. The gene encoding the HLA-DR3/Dw3 specificity has been generated by a gene conversion involving theDRβIand theDRβIIIloci of the HLA-DRw6/Dwl8haplotype, as recipient and donor gene, respectively. Based on which allele is found atDRβIII, the less polymorphic locus, two groups of haplotypes can be defined:DRw52aandDRw52b. The generation of HLA-DR polymorphism within theDRw52supertypic group can thus be accounted for by a succession of gene duplication, divergence and gene conversion.