Characterization of the b99 allotype of rabbit immunoglobulin kappa 1 light chain.

A previously undetected allotypic specificity, A99, was found in a wild rabbit (Oryctolagus cuniculus) population in Portugal. The A99 allotype cross-reacted with anti-b6 and anti-b96 sera, but carried its own antigenic determinants and was therefore distinct from the known allotypes of the b series. The A99 determinants were located on the kappa 1 light chain of IgG molecules and were inherited as allotypic determinants of the b series. Taken together, these data provide evidence that A99 is encoded by an allele at the b locus, tentatively designated b99. The great similarity between the b6, b96 and b99 allotypes suggests that they derived from a common ancestor.