Cloning and sequencing of two functional rabbit germ-line immunoglobulin V lambda genes.

A recombinant-phage library of rabbit genomic DNA was screened for immunoglobulin V lambda genes. Two functional genes, V lambda 2 and V lambda 3, which are separated by 1.6 kb were isolated and sequenced. Both are accompanied by signals required for transcription-translation and the recombination with J lambda genes. The two genes, which are 95% similar in their framework regions, may be the parents of several cDNAs encoding V lambda regions. Rabbit V lambda-region diversity is likely to be generated by somatic mutation and V-J junction flexibility. Two cDNA clones encoding lambda-light chains may have arisen by gene conversion, exchanging the complementarity-determining regions, CDR3s, of the V lambda 2 and V lambda 3 genes.