GENETIC-MAPPING OF THE COMPONENT CHAINS OF IA ANTIGENS

The genes encoding the two polypeptide chains (α and β) that comprise the murine Ia antigens were localized within distinct regions of the major histocompatibility complex (MHC). This was accomplished by correlating allelic forms of the α and β chains with the MHC congenic strains of mice from which they were isolated. Allelic forms of α and β chains were distinguished by their unique structural markers, such as isoelectric points, amino acid sequences or peptide maps. The results indicate that the structural genes for both the α and β chains of I-A subregion antigens are located within the K to I-A genetic interval. In contrast, the gene encoding the β chain of I-E subregion antigens is located outside of the I-E subregion and within the K to I-B genetic interval. These findings may have important implications for analysis of observations that complementation by two I-region genes is sometimes required for development of immune responses. © 1979 Springer-Verlag New York Inc.