Inactivation of rabbit immunoglobulin λ chain variable region genes by the insertion of short interspersed elements of the C family

Abstract

Two rabbit germ‐line genes encoding immunoglobulin λ light chain V regions were cloned from a rabbit genomic liver DNA library and characterized. One, V_λ1, is separated by at least 8 kb from any other V_λ gene. The second, V_λ4, forms part of a three‐gene cluster with two functional V_λ genes recently reported. Both V_λ1 and V_λ4 have structural features rendering them pseudogenes. The coding regions have frame‐shift mutations which would yield defective protein products; both genes are also interrupted by the insertions of short, interspersed repetitive elements of the C family. In the V_λ1 gene, the 369‐bp insert is located upstream of the gene between the putative TATA box and the leader exon, whereas in gene V_λ4, the 360‐bp insert interrupts the FR2 at codon 48c. In addition, the sequence of the complement‐determining region 3 of gene V_λ1 is very similar to the mouse DSP2.6 sequence.