A linkage map of the mouse immunoglobulin lambda light chain locus.

The mouse immunoglobulin lambda light chain locus has been linked using field inversion gel electrophoresis. The lambda light chain locus classically contains two V and four J-C gene segments in inbred mouse strains, and was physically mapped in the BALB/c cell line Wehi-3 which contains unrearranged lambda light chain gene segments. The locus is relatively small and spans 300 kb, as defined by a variety of single and double digests using methylation-sensitive restriction enzymes. The order of the lambda gene segments is V2-J2C2J4C4-V1-J3C3J1C1, as was originally proposed. No evidence for nonmethylated CpG rich areas (HTF islands) within the region was found. Fine mapping using the lambda 1, lambda 3 rearranged cell line J558 mapped the gap between the V and J-C gene segments in the lambda 1 gene cluster (V1-J3C3J1C1) to approximately 70 kb. The similar distance (60-100 kb) found in the lambda 2 gene cluster (V2-J2C2J4C4) is further evidence that duplication of an ancestral locus occurred.