Ayadi H, Cazenave P A, Marche P N
Département d'Immunologie, Institut Pasteur, CNRS UA 359, Paris, France.
Eur J Immunol. 1990 Feb;20(2):259-64. doi: 10.1002/eji.1830200205.
The third complementary-determining regions (CDR3) of rabbit kappa chains are unusually long and the length is more heterogeneous when compared to those of the mouse and the human kappa chains. To study how the rabbit kappa light (L) chain genes create diversity and generate CDR3, we analyzed the structure of a rearranged variable kappa gene (Vr) and the variable (Vg) and joining (Jg) regions of the putative precursor genes. Alignment of the Vr gene sequence with that of the Vg and Jg regions allowed precise determination of the recombination event. Five nucleotides between the recombination point and the J2 heptamer were deleted, indicating flexibility in the recombination producing rabbit kappa chains. The entire Vg is contained in the rearranged product demonstrating that neither a D element nor an N sequence addition are required for the CDR3 formation. Comparison of the Vr and the Vg gene sequences show base substitutions suggesting that somatic mutations may contribute to rabbit kappa L chain diversity.
兔κ链的第三个互补决定区（CDR3）异常长，与小鼠和人类κ链相比，其长度的异质性更高。为了研究兔κ轻链（L）基因如何产生多样性并生成CDR3，我们分析了一个重排的可变κ基因（Vr）以及推定前体基因的可变区（Vg）和连接区（Jg）的结构。将Vr基因序列与Vg和Jg区的序列进行比对，能够精确确定重组事件。重组点与J2七聚体之间的五个核苷酸缺失，这表明在产生兔κ链的重组过程中存在灵活性。重排产物中包含了整个Vg，这表明CDR3的形成既不需要D元件也不需要N序列添加。Vr和Vg基因序列的比较显示存在碱基替换，这表明体细胞突变可能对兔κ轻链的多样性有贡献。
