Murre C, Waldmann R A, Morton C C, Bongiovanni K F, Waldmann T A, Shows T B, Seidman J G
Nature. 1985;316(6028):549-52. doi: 10.1038/316549a0.
Three gene families that rearrange during the somatic development of T cells have been identified in the murine genome. Two of these gene families (alpha and beta) encode subunits of the antigen-specific T-cell receptor and are also present in the human genome. The third gene family, designated here as the gamma-chain gene family, is rearranged in murine cytolytic T cells but not in most helper T cells. Here we present evidence that the human genome also contains gamma-chain genes that undergo somatic rearrangement in leukaemia-derived T cells. Murine gamma-chain genes appear to be encoded in gene segments that are analogous to the immunoglobulin gene variable, constant and joining segments. There are two closely related constant-region gene segments in the human genome. One of the constant-region genes is deleted in all three T-cell leukaemias that we have studied. The two constant-region gamma-chain genes reside on the short arm of chromosome 7 (7p15); this region is involved in chromosomal rearrangements identified in T cells from individuals with the immunodeficiency syndrome ataxia telangiectasia and observed only rarely in routine cytogenetic analyses of normal individuals. This region is also a secondary site of beta-chain gene hybridization.
在小鼠基因组中已鉴定出在T细胞体细胞发育过程中发生重排的三个基因家族。其中两个基因家族（α和β）编码抗原特异性T细胞受体的亚基，在人类基因组中也存在。第三个基因家族，在这里被指定为γ链基因家族，在小鼠细胞毒性T细胞中发生重排，但在大多数辅助性T细胞中不发生重排。在这里，我们提供证据表明，人类基因组中也含有在白血病来源的T细胞中发生体细胞重排的γ链基因。小鼠γ链基因似乎由与免疫球蛋白基因可变区、恒定区和连接区片段类似的基因片段编码。人类基因组中有两个密切相关的恒定区基因片段。在我们研究的所有三种T细胞白血病中，其中一个恒定区基因被删除。两个恒定区γ链基因位于7号染色体短臂（7p15）上；该区域参与了在患有免疫缺陷综合征共济失调毛细血管扩张症个体的T细胞中鉴定出的染色体重排，在正常个体的常规细胞遗传学分析中很少观察到。该区域也是β链基因杂交的次要位点。
