Serologic variations in kappa light chains of various Mus species correlate with differences in gene structure

Kappa light chains were investigated in sera of several groups of wild derived mouse strains by radioimmunological analysis using xenogeneic anti-mouse kappa light chain antibodies. Although the majority of strains tested expressed serologically indistinguishable kappa chains, several significant exceptions were observed. Anti-kappa chain reactivity was not detectable in normal sera of Mus caroli and Mus cervicolor species using specific antiserum. These strains express a variant of the kappa light chain. Some serologic variation was also observed in kappa chains from members of the subgenus Nannomys. Southern blot analyses using C kappa and J kappa probes indicated different patterns of hybridization in strains that were serologically distinguishable. Mus caroli and Mus cervicolor DNAs digested with the enzymes EcoRI or BamHI show variation from BALB/c and most other mouse strains tested in the size of the hybridizing fragments. This correlation between serologic and blotting analyses is no longer found in SJL and SPE strains, which show variation in BamHI cleavage but not at the serological level. The majority of laboratory and wild derived mice analyzed have the same pattern of hybridization. Taken together our results may also have implications for the phylogenetic classification of wild type mouse strains.