The central part of the mouse immunoglobulin kappa locus

At the present state of analysis the central part of the kappa locus compri ses four contigs of together 1.2 Mb and contains 55 V kappa genes. It is fl anked by the 3' part of the locus with 22 V kappa genes in 0.4 Mb (T. Kirsc hbaum et al., Eur. J. Immunol. 1998. 28: 1458-1466) and the 5' part with 63 V kappa genes in six contigs of together 1.5 Mb (F. Roschenthaler et al., accompanying report). The 5' and the central regions have one large contig in common. A part of the central region is linked to the 3' region resultin g in a 1.1-Mb contig. The structure of the contigs was established mainly b y the analysis of overlapping cosmid clones derived from genomic DNA and ye ast and bacterial artificial chromosomes (YACs and BACs) and by PCR techniq ues. Pulsed-field gel electrophoresis of YAC digests indicated that three g aps between the contigs of the central region are 10-40 kb in size, compris ing together about 90 kb. Internal duplications in this part of the locus a nd rearranged YACs were the major problems of the structural work. Structur al details are to be found on the Internet at http://www.med.uni-muenchen.d e/biochemie/zachau/kappa.htm. In a concluding section of the report the mou se kappa locus is compared to the human one and some aspects of the evoluti on of the x locus are discussed.