Genetic analysis of the T/t complex.

The T/t-complex has held considerable interest for immunologists, primarily because of its close genetic linkage to the major histocompatibility complex (MHC) on mouse chromosome 17. This interest has been heightened recently with the discovery that the MHC is fully contained within the t-complex and that two regions of the MHC, Qa and K, contain t-lethal genes. For a long time, T/t has been an enigmatic system, mainly because classical genetic analysis was not possible. Here the system is defined, recent information is presented, and our understanding of the mouse data to available information about the human MHC is correlated.