Najakshin A M, Belousov J S, Bogachev S S, Taranin A V
Institute of Cytology and Genetics, Novosibirsk, Russia.
Mol Immunol. 1993 Sep;30(13):1205-12. doi: 10.1016/0161-5890(93)90139-3.
Screening of a mink cDNA library with an antibody probe resulted in the isolation of clone pIGL-2 containing an Ig lambda chain coding sequence. The sequence comprised almost the entire V segment as well as J, C, and 3'-untranslated sequences. A second clone, pIGL-10, was isolated by rescreening the cDNA library with the use of pIGL-2 as a probe. pIGL-10 was found to contain a frameshift deletion of a single nucleotide in the C region. pIGL-2 and pIGL-10 were 81% homologous to each other in the FR3 of the V segment, and 95% of homology was found in their C regions. The J segments of the two clones differed in only one nucleotide position. Comparison of cloned lambda chain sequences with those of other mammals revealed that mink V lambda and C lambda genes have the highest homology with their human counterparts. The V lambda sequence of clone pIGL-2 appears to be a homologue of human subgroup III V lambda genes. Southern blot hybridization of mink DNA with the C lambda and V lambda probes derived from pIGL-2 revealed five or six hybridizing C lambda fragments and at least 11 hybridizing V lambda fragments. This suggested that the lambda genes in carnivores, like those in primates, have duplicated extensively during evolution.
用抗体探针筛选水貂cDNA文库，分离出包含Igλ链编码序列的克隆pIGL - 2。该序列几乎包含整个V区段以及J、C和3'非翻译序列。通过用pIGL - 2作为探针重新筛选cDNA文库，分离出第二个克隆pIGL - 10。发现pIGL - 10在C区域存在一个单核苷酸的移码缺失。pIGL - 2和pIGL - 10在V区段的FR3中彼此同源性为81%，在其C区域发现95%的同源性。两个克隆的J区段仅在一个核苷酸位置上不同。将克隆的λ链序列与其他哺乳动物的序列进行比较，发现水貂Vλ和Cλ基因与其人类对应基因具有最高的同源性。克隆pIGL - 2的Vλ序列似乎是人类III亚组Vλ基因的同源物。用水貂DNA与源自pIGL - 2的Cλ和Vλ探针进行Southern印迹杂交，显示出五六个杂交的Cλ片段和至少11个杂交的Vλ片段。这表明食肉动物中的λ基因，与灵长类动物中的一样，在进化过程中已经广泛复制。
