Many animals are able to distinguish unfamiliar kin from nonkin by odor cues. How do chemical signals reveal whether or not individuals are genetically related? One possibility is that odor cues are influenced by genes that are very diverse, thus kin will share odors because they share versions (alleles) of these odor influencing genes. Genes of the major histocompatability complex (MHC) are postulated to play this kin recognition role in vertebrates because they are extremely diverse, they influence odor and they influence behavior expected to involve kin, including cooperation and inbreeding avoidance. This study tests a number of critical predictions of this hypothesis that are currently uncertain, and should provide important answers. The proposed studies have several important implications. They will help to clarify how genes influence complex social behavior, one of the most puzzling problems in biology today. The research will help to unravel the genetic basis and development of chemosensory communication. This work will determine if MHC genes provide a genetic kin recognition system in mice. In addition the research has direct implications for humans because recent studies have found that women prefer the odor of MHC-dissimilar men and the marriage patterns predicted by such preferences have been found in some human populations.
