Post-stress changes in the attractiveness of female mouse chemosignals to intact males.

During the early period (1-4 days) after stress, female CBA and C57BL6 (B6) mice were found to excrete volatile components (chemosignals) in the urine, which are more attractive to intact males of these same strains, regardless of genotype, than the secretions of intact females. At later time point; there were wavelake changes in the attractiveness of the secretions of stressed females, though the difference between the intact and stressed groups of females disappeared by one month. Comparison of the secretions of stressed CBA and B6 females showed that intact males preferred the post-stress chemosignals of syngeneic (genetically identical) individuals during the period 1-14 days. This phenomenon - post-stress reversion of the female genotype-dependent olfactory attractiveness to males - was significantly different from normal, where males show a consistent preference for the chemosignals of allogeneic (with different genotypes) females. The pattern of male preference for the chemosignals of stressed syngeneic females was also seen on direct comparison with the chemosignals of intact allogeneic females. Normal female chemosignaling recovered during the 2-3 weeks after stress. The biological significance of these phenomena is discussed.