The variable genes and gene families of the mouse immunoglobulin κ locus

Open Access
Publisher Website
Google Scholar
Abstract
In this report 118 mouse Vκ genes are described which, together with the 22 Vκ genes reported previously (T. Kirschbaum et al., Eur. J. Immunol. 1998. 28: 1458 – 1466) amount to 140 genes that had been cloned and sequenced in our laboratory. For 73 of them cDNAs are known, i. e. they have to be considered functional genes, although 10 genes of this group have 1‐bp deviations from the canonical promoter, splice site or heptanucleotide recombination signal sequences. Twenty Vκ genes have been defined as only potentially functional since they do not contain any defect, but no cDNAs have been found (yet) for them. Of the 140 Vκ genes 47 are pseudogenes. There are indications that two to five Vκ genes or pseudogenes exist in the κ locus which we have not yet been able to clone. The 140 Vκ genes and pseudogenes were assigned to 18 gene families, 4 of them being one‐member families. This differs from previous enumerations of the families only by the combination of the Vκ9 and Vκ10 families and by the addition of the Vκdv gene as a new separate family. Sequence identity usually was 80 % or above within the gene families and 55 – 80 % between genes of different families. Many of the mouse Vκ gene families show significant homologies to the human ones, indicating that in evolution Vκ gene diversification predated the divergence of the primate and rodent clades.