A polymorphism of the gamma-chain of mouse C4 controlled by the S region of the major histocompatibility complex.

Three phenotypes of the gamma-chain of mouse C4 have been detected by a modification of the two-dimensional O'Farrell technique. Strains carrying the H-2s, H-2p, H-2f and H-2ja haplotypes had chains with pI 7.4 (gamma 1). Strains with H-2k, H-2q, H-2d, H-2r, H-2b, H-2u, and H-2w7 had gamma-chains with pI 6.9 (gamma 2), and strains carrying a wild-derived haplotype had gamma chains with pI 6.5 (gamma 3). The genes controlling this polymorphism were mapped in the S region of the H-2 complex by using congenic strains.