Recombination between kappa chain genetic markers in the mouse.

In this study we report the first instance of recombination between kappa chain genetic markers in the mouse. The recombination frequency, 0.45% (95% limits, 0.12-1.61), is similar to that previously found for recombination between the kappa chain locus and the Lyt-2,3 locus (0.3%, 95% limits, 0.05-1.6), but is relatively low in comparison with that found at the heavy chain locus (0.41-5.4%). Lyt-2,3-typing of the recombinants permits a partial ordering of the kappa chain and Lyt-2,3 loci as (Lyt-2,3, Igk-Ef1) - Igk-Ef2. Light chains controlled by the two kappa markers include the Vk-(ser) subgroup (controlled by Igk-Ef1) and Vk-1 (controlled by Igk-Ef2). One of the recombinants has been recovered in a homozygous state ("NAK") and should be suitable for Vk gene mapping studies.