Abstract
Two experiments tested whether the male urinary chemosignal that accelerates puberty in female mice or the urinary chemosignal from grouped females that delays puberty were affected by circadian rhythms. The experiments also tested whether there is a circadian component for the response system(s) of the young recipient female mice for the onset of 1st vaginal estrus. Male urine collected at 0600 h was more effective in inducing earlier maturation than urine collected at 0000, 1200 or 1800 h. Urine from grouped females collected at all 4 times produced significant delays in 1st estrus, but urine collected at 0000 h produced longer delays than urine from 0600, 1200 or 1800 h. For male urine, application at 0600 h produced significant acceleration relative to urine treatment at 0000, 1200 or 1800 h. No differences were recorded in age of puberty in females treated with urine grouped from females when urine was applied at the 4 different time points. Possible interpretations of these results involve circadian variations for various hormones and related physiological processes in donor and recipient mice.