Biochemical evidence for trans complementation of structural genes in the expression of I-E antigens in F1 hybrids.

Analysis of the tryptic peptides obtained from the Ia.7-positive, "I-E" antigens produced by 4 F1 combinations derived from strain A.TFR5 has provided biochemical confirmation that I-A/I-E gene complementation can occur in the transconfiguration. The data obtained support the concept that structural genes, as opposed to regulatory genes, are the essential elements involved in this complementation and support the assignment of the I-E subregion of strain A.TFR5 as I-Ek. The data support the following assignments of the genes encoding the E beta chains: B10.A(4R) as E beta k, B10.A(5R) as E beta b, and B10.HTT as E beta s. Finally, data are presented demonstrating that the E beta chain derived from the recombinant D2.GD strain partially differs from the E beta d chain derived from a conventional H-2d haplotype strain, B10.D2.