IgD allotypic determinants. II. Determinants expressed on IgD of mice of the b, e, and o Igh-C haplotypes.

Allotypic determinants expressed on membrane IgD of 27 strains of mice representing each of the major Igh-C haplotypes of inbred mice were examined with reagents specific for the IgD of mice of the b, e, and o Igh-C haplotypes. The distribution of two specificities, IgD.44 (Ig5.2) and IgD.37 (Ig5.3), recognized by two monoclonal anti-delta reagents was determined. In addition, a new specificity, IgD.46, expressed on mice of the o Igh-C type, but not of the b or a types, was detected by a BALB/c anti-AL/N spleen cell antiserum. The results also confirmed the description of the new Igh-C haplotype o, by demonstrating that the mice of this group express the IgD.37 determinant. This determinant is also expressed by mice of the b and e types, but not by mice of the d haplotype, from which the o haplotype was subdivided.