Rogers J H, Willison K R
Nature. 1983;304(5926):549-52. doi: 10.1038/304549a0.
A proportion of wild mice carry a chromosome 17 of which a large part is very different from the standard mouse chromosome 17. The affected region is called the t complex, and the anomalous chromosomal types are the t haplotypes. In combination with various other chromosomes 17, t haplotypes can produce crossover suppression, taillessness, transmission distortion, male sterility and lethality early in development. The various t haplotypes also carry H-2 specificities which are different from those of other mice. This, together with the fact that the lethality genes map to both sides of H-2, suggests that the major histocompatibility complex is contained within the t complex. The lack of recombination between t haplotypes and standard chromosomes 17 may be due to large-scale rearrangements. Genetic data support this idea, in that the tufted gene, the H-2 complex and a group of H-2-related genes appear to be in inverted order in t haplotypes relative to the standard chromosome 17. The mapping of several t-lethal factors close to the H-2-related genes in t haplotypes suggests that breakpoint(s) may be found here. We have now investigated the major histocompatibility complex of t haplotypes by Southern blots using a variety of cloned DNA probes, and find a major rearrangement, specific to the t haplotypes, in the Qa-2,3 region of the complex. This involves the loss of several large homology units, probably including several class I H-2-related genes, and the creation of two possible breakpoints.
一部分野生小鼠携带17号染色体，其中很大一部分与标准小鼠17号染色体有很大差异。受影响的区域称为t复合体，异常染色体类型为t单倍型。与各种其他17号染色体结合时，t单倍型可产生交叉抑制、无尾、传递畸变、雄性不育和发育早期致死。各种t单倍型还携带与其他小鼠不同的H-2特异性。这一点，再加上致死基因定位于H-2两侧的事实，表明主要组织相容性复合体包含在t复合体内。t单倍型与标准17号染色体之间缺乏重组可能是由于大规模重排。遗传数据支持这一观点，因为簇状基因、H-2复合体和一组与H-2相关的基因在t单倍型中相对于标准17号染色体似乎呈倒序排列。在t单倍型中，几个t致死因子定位于与H-2相关的基因附近，这表明可能在这里找到断点。我们现在使用各种克隆的DNA探针，通过Southern印迹法研究了t单倍型的主要组织相容性复合体，发现在该复合体的Qa-2,3区域存在一种特定于t单倍型的主要重排。这涉及到几个大的同源单位的缺失，可能包括几个I类H-2相关基因，并产生了两个可能的断点。
