9222177 Potts The genes of the major histocompatibility complex (MHC) play a major role in immune recognition. Because of this, it has generally been assumed that their unequalled genetic diversity results from parasite-driven selection. However, these genes may also function in a genetic-based kin-recognition system. This possibility is indicated by Dr. Potts' recent demonstration that female house mice prefer to mate with MHC-dissimilar males, but prefer to nest communally with MHC-similar females. Dr. Potts will now attempt to extend these findings in two major ways. First, discrimination in kin-recognition systems requires a referent to which other individuals are compared. Dr. Potts will use MHC-based mating preferences in a seminatural population of house mice as an assay to determine (1) whether self, a parent, a nestmate, or some combination is the referent, and (2) the nature of the rules for matching MHC haplotypes. Second, to determine whether or not the unique features of MHC (known primarily from studies of mice) are general vertebrate traits, Dr. Potts will evaluate MHC-related patterns of fitness, mating, and genetic diversity in natural populations of five other vertebrate species. If MHC genes are generally involved in disease resistance, mating preferences, and kin recognition in vertebrate species, understanding the mechanisms and function of this MHC-based discrimination will have important implications for a wide range of areas in vertebrate biology. These areas include the evolution of immune-recognition systems, the evolution of social behavior, modulation of kin-based cooperation, inbreeding- avoidance mechanisms, and the genetic basis of mating behavior and kin discrimination.
