Participation of the murine X and Y chromosomes in genetically determined chemosensory identity.

The major histocompatibility complex of the mouse imparts to each mouse an odor that reflects its genetic constitution at this region of chromosome 17. Sensory recognition of these differential odors influences reproductive behavior and evokes neuroendocrine responses critical to the maintenance of pregnancy. To determine whether other parts of the mouse genome contribute to individual scent marking, and so may similarly exert a selective force on loci other than the major histocompatibility complex, mice differing genetically only in their X and/or Y chromosomes were tested for individuality of scent in the Y-maze system previously employed to investigate major histocompatibility complex-related scent distinctions. It is shown that the X and Y chromosomes each confer individually of scent related to genotype.