Abstract
The contribution of the b5, c7 and c21 genes to the formation of a single γG-immunoglobulin molecule has been analyzed in partially b5 suppressed b5b5 homozygous rabbits of phenotype c7c21. This was done by means of direct precipitation of 125I-labeled γG preparations with anti-b5, anti-c7 or anti-c21 as well as by indirect precipitation of these allotypes with anti-b4. No two of the allotypic specificities, b5, c7 or c21 were found on the same molecule. This indicates that neither the two unlinked light chain loci b and c, nor the allelic genes c7 and c21 contribute to the formation of the same molecule.
Two light polypeptide chain peaks were obtained after partial reduction and alkylation of the γG-immunoglobulins. Quantitative allotype analysis revealed that b5, c7 and c21 light chains accounted for all of the molecules in the first light chain peak, and only b5 light chains accounted for all of the molecules of the second peak. The c21 allotypic specificity is on the light chains as previously found for the b5 and c7 specificities.
Footnotes
Allotypic specificities Ab4, Ab5, Ac7 and Ac21 are abbreviated to b4, b5, c7 and c21; the genes are b4, b5, c7 and c21.
Presented in part as an abstract at the 53rd Annual Meeting of the Federation of American Societies for Experimental Biology, Atlantic City, New Jersey, April 13–18, 1969.
Supported by a Research Grant PHS A1-0743 from the National Institutes of Allergy and Infectious Diseases and by the National Science Foundation Grant GB-5536.
