Gerstein R M, Lieber M R
Department of Pathology, Stanford University School of Medicine, California 94305-5324.
Nature. 1993 Jun 17;363(6430):625-7. doi: 10.1038/363625a0.
Among site-directed DNA recombination systems, V(D)J recombination is noteworthy in that identical reactants yield different recombination products at the junction of joined segments. This variation is the basis for diversity at the base of antigen receptor binding pockets and corresponds to V-(D)-J DNA junctions. An abundance of certain junctions has been noted. It has been proposed that these junctions are favoured because they occur where short regions of homology in participating coding ends might align preferentially. Here we use a system that is entirely free from cellular selection to show that the diversity of coding joints can be severely restricted when the coding ends participating in the reaction have short regions of homology. This constraint on diversity is diminished but not eliminated by terminal deoxynucleotidyl transferase, a mechanistic feature that has implications for the establishment of the immune repertoire.
在定点DNA重组系统中，V(D)J重组值得关注，因为相同的反应物在连接片段的连接处会产生不同的重组产物。这种变异是抗原受体结合口袋底部多样性的基础，并且与V-(D)-J DNA连接相对应。已经注意到某些连接的丰度。有人提出，这些连接受到青睐是因为它们出现在参与编码末端的短同源区域可能优先对齐的地方。在这里，我们使用一个完全不受细胞选择影响的系统来表明，当参与反应的编码末端具有短同源区域时，编码接头的多样性可能会受到严重限制。末端脱氧核苷酸转移酶减少了对多样性的这种限制，但并未消除，这一机制特征对免疫库的建立具有影响。
