[Evolution of the rabbit kappa light chain: multiple substitutions between allelic forms].

The partial amino acid sequence of the rabbit IgG light chain constant region of allotype b6 was determined by analyzing tryptic digests. The comparison of available data on b4, b5, b6 and b9 constant region sequences reveal multiple differences ranging from 35% between b4 and b9 or between b6 and b9 chains, to 24% between b4 and b6 chains. This large number of substitutions suggests an early divergence of the b constant region structural genes into to-day's four polymorphic forms.