ABSTRACT
The molecules encoded by the major histocompatibility complex (MHC) genes play a critical role in the rejection of organ transplants and the control of the immune response. Serological analyses of recombinant MHC chromosomes in mice and man have been used to construct genetic maps for the murine and human MHC’s. Mouse and human class I and class II genes show similar structural variations at their 3' ends. It is not clear whether these changes are important for different effector functions of the molecules and for distinct interactions with cytoskeletal proteins or whether they simply reflect evolutionary variations of a nonfunctional carboxyl terminus. Mouse and human class II genes have been introduced into mouse L cells and successfully expressed at the cytoplasmic and cell-surface levels. Compared to the limited number of class I molecules identified serologically, it was surprising to find that the mouse contains about 40 class I genes.
