Physical map of the mouse lambda light chain and related loci.

The lambda light chain genes and the related loci lambda 5, V(preB)1 and V(preB)2 are selectively expressed in the development of B lymphocytes. The sequences and the order of the gene segments are known, but a precise physical map of the lambda locus has not yet been published. Using the Celera mouse genome database we constructed such a map. In this paper, we confirm the order of the gene segments as being V lambda 2 - V lambda X - J lambda 2 - C lambda 2 - J lambda 4 - C lambda 4 - V lambda 1 - J lambda 3 - C lambda 3 - J lambda 1 - C lambda 1 and give precise germ line distances. We located the V(preB)2 locus 3' to the lambda locus, 1,077,001 bp downstream; the V(preB)1 locus, 2,180,618 bp downstream of the lambda locus; and the lambda 5 gene, 4,667 bp downstream of the V(preB)1 locus. Except for the V(preB)2 locus all other loci are in the same transcriptional orientation.