Removal of the preputial glands alters the individual odors of male MHC-congenic mice and the preferences of females for these odors.

Inbred mice of MHC-congenic strains prefer to mate with mice of different MHC types. Mate selection based on MHC-type occurs through the urinary odors specific to each MHC-congenic mouse strain. Both urine and preputial gland odors of male mice have been postulated to act as female attractants and the present study examined the attraction of MHC-congenic female mice (C57BL/6J and B6-AKR.H-2k) to the urine and preputial gland odors of males. Females of both strains showed a greater attraction to the urine odors of intact males of the other MHC type, but did not show a preference for the urine odors of these males after their preputial glands were removed. There was, however, a preference for the preputial fluid of males of the other MHC type. These results indicate that the MHC-specific urinary odors of mice may arise from the preputial glands, and that it is the MHC-specific preputial gland odors of MHC-conspecific males that are used for mate selection by females.