Bullard D C, Schimenti J C
Department of Genetics, Case Western Reserve University, Cleveland, Ohio 44106.
Genetics. 1990 Apr;124(4):957-66. doi: 10.1093/genetics/124.4.957.
Male transmission ratio distortion (TRD) is a property of mouse t haplotypes requiring the t complex responder locus (Tcr). Tcr maps to the central region of t haplotypes, and is embedded within a series of large duplicated tracts of DNA known as "T66 elements." In previous work, a family of genes (the "T66" genes) was identified within this region that encodes male germ cell-specific transcripts. Genetic and molecular data indicate that one of these genes represents Tcr. Here, we describe the molecular cloning of the four members of the T66 gene family, the genetic mapping of these genes to three adjacent t haplotype loci, and comparative restriction enzyme analysis of the genes. The results indicate that these genes are highly similar to one another, and were created by recent, complex duplication events. This suggests that a minor alteration(s) could have been responsible for conferring "mutant" responder activity upon Tcr, while the other homologs retained "wild-type" biochemical function. In addition, we have identified and mapped three T66 genes in wild-type t complexes. They reside in two separate loci at the opposite ends of the proximal t complex inversion, and are separated by at least 3 cM.
雄性传递比例失真（TRD）是小鼠t单倍型的一种特性，需要t复合反应位点（Tcr）。Tcr定位于t单倍型的中心区域，并嵌入一系列称为“T66元件”的大型重复DNA片段中。在先前的研究中，在该区域内鉴定出一个基因家族（“T66”基因），其编码雄性生殖细胞特异性转录本。遗传和分子数据表明，这些基因中的一个代表Tcr。在此，我们描述了T66基因家族四个成员的分子克隆、这些基因在三个相邻t单倍型位点的遗传定位以及基因的比较限制性酶切分析。结果表明，这些基因彼此高度相似，是由近期复杂的复制事件产生的。这表明一个或几个微小的改变可能赋予Tcr“突变”反应活性，而其他同源基因保留“野生型”生化功能。此外，我们在野生型t复合体中鉴定并定位了三个T66基因。它们位于近端t复合体倒位两端的两个独立位点，相隔至少3厘摩。
