Spielman R S, Lee J, Bodmer W F, Bodmer J G, Trowsdale J
Proc Natl Acad Sci U S A. 1984 Jun;81(11):3461-5. doi: 10.1073/pnas.81.11.3461.
Analysis of cosmid clones containing genes related to the HLA-DR alpha chain calls for at least six HLA-D region alpha-chain coding sequences in man; namely, DR alpha, DC alpha, DX alpha (very closely related to DC alpha), SB alpha 1, SB alpha 2 (two closely linked genes on the same cosmid clones), and DZ alpha. The first four genes have been described previously. SB alpha 2 and DZ alpha are recently identified genes, characterized by their unique and, from a limited study, nonpolymorphic bands when used as probes for human DNA on Southern blots. All of the genes are present in somatic cell hybrids containing a human X/6 translocation chromosome, and so they are all presumably in the HLA region. The polymorphisms in the region of the DC alpha and related DX alpha genes were studied with Southern blots of DNA from a set of mostly homozygous HLA-D-typing cell lines. With EcoRI, the band patterns for the DC alpha gene corresponded to the major cross-reactive HLA-DR serotypes associated with DC (namely MT1, -2, and -3) while the DX alpha band was invariant. Both genes were polymorphic with the enzyme Taq I. Within some DR types additional polymorphic variation was detected at the DNA level, implying the existence of subtypes. The pattern of polymorphisms for DC alpha, and to a lesser extent for DX alpha, suggests that these genes may play an important role in certain HLA-D associations with disease.
对含有与HLA - DRα链相关基因的黏粒克隆进行分析表明，人类至少有六个HLA - D区域α链编码序列；即DRα、DCα、DXα（与DCα密切相关）、SBα1、SBα2（位于同一黏粒克隆上的两个紧密连锁基因）和DZα。前四个基因先前已被描述。SBα2和DZα是最近鉴定出的基因，其特征在于，当用作Southern印迹中人DNA的探针时，它们具有独特的、且根据有限研究为非多态性的条带。所有这些基因都存在于含有人类X/6易位染色体的体细胞杂种中，因此它们可能都位于HLA区域。利用一组大多为纯合HLA - D分型细胞系的DNA进行Southern印迹，研究了DCα及相关DXα基因区域的多态性。用EcoRI酶切时，DCα基因的条带模式与与DC相关的主要交叉反应性HLA - DR血清型（即MT1、-2和-3）相对应，而DXα条带是不变的。这两个基因用Taq I酶切时都是多态的。在某些DR类型中，在DNA水平检测到了额外的多态性变异，这意味着存在亚型。DCα的多态性模式，以及程度稍低的DXα的多态性模式，表明这些基因可能在某些HLA - D与疾病的关联中起重要作用。
