STUDIES OF IMMUNOGLOBULIN GENE REARRANGEMENT

我们在抗原受体基因重排（V（D）J 重组）描述了一种类型的断裂DNA分子， 在这个过程中的中间体。 这些分子， T细胞受体δ基因座（TCR）仅具有含有 重组信号序列 我们现在也能够找到断裂的分子， 编码序列，但只有在DNA与scid突变， 干扰这些端部的连接。发现编码末端 有一个异常的结构：两条DNA链彼此相连 发夹结构。发夹的存在提供了一个很好的 免疫球蛋白和T细胞受体中观察结果的解释 编码接头，在形成过程中形成的自互补序列 重组 如果发夹结构偏离中心， 自然会产生互补插入。 这些结果加强了断裂-团聚模型的证据， V（D）J复合，也表明该过程必须 与之前的例子不同。

Our earlier work on antigen receptor gene rearrangement (V(D)J recombination) described one type of broken DNA molecules that were plausible intermediates in this process. These molecules, seen at the T cell receptor delta locus (TCR), had only the free end containing the recombination signal sequence. We have now also been able to find broken molecules with the end of the coding sequence, but only in DNA from mice with the scid mutation, which interferes with the joining of these ends. The coding ends are found to have an abnormal structure: the two DNA strands are linked to each other in a hairpin configuration.The presence of hairpins offers a good explanation for the observation, in immunoglobulin and T cell receptor coding junctions, of self- complementary sequences formed during recombination. If a hairpin structure is nicked off-center, a self- complementary insertion will naturally result. These results strengthen the evidence for a breakage-reunion model of V(D)J recombination, but also indicate that the process must be different from earlier examples of this type.