THE 3' PART OF THE IMMUNOGLOBULIN-KAPPA LOCUS OF THE MOUSE

A detailed restriction map of a 430-kb contig comprising the single C kappa, the 5 JH and the adjoining 22 V kappa gene segments is presente d. The first 12 V kappa genes following the J kappa C kappa region bel ong to the V kappa 21 family, the subsequent ones to the closely relat ed families V kappa 8 and V kappa 19/28. Previous difficulties in clon ing all V kappa 21 genes can now be explained by the presence of a dup licated region in this part of the locus. The structure was establishe d by analysis of yeast artificial chromosome, bacterial artificial chr omosome and cosmid clones and by the so-called long template PCR techn ique. The distance between C kappa and the proximal V kappa 21 gene is 22 kb and the average distances between the V kappa genes are about 2 0 kb. Of the 12 V kappa 21 genes 5 were sequenced for the first time a nd 8 of the 12 genes were found to be expressed. Of the 10 V kappa 8 a nd V kappa 19/28 germline genes 9 are new; expression products of 8 of the 10 genes were known. The known 5', 3' polarities allow to specify for the 22 V kappa genes whether they are rearranged to the J kappa C kappa element by a deletion or an inversion mechanism. Also the forma tion of interesting rearrangement products in classical cell lines as MPC11, MOPC41 and PC7043 can be explained now. The non-V kappa sequenc e L10 whose rearrangement by inversion has been described earlier (Hoe chtl and Zachau, Nature 1983. 302: 260-263) was now localized downstre am of J kappa C kappa.