Delay and acceleration of puberty in female mice by urinary chemosignals from other females.

A sequence of 7 experiments tested various aspects of the acceleration and delay of sexual maturation in young female mice as affected by cues from other females: Singly caged females produce the maturation-delaying chemosignal when exposed to urine from grouped females. Urine from females housed 3 or more/cage produces delays in puberty for young females. Urine from females in estrus accelerates puberty in young females relative to untreated controls or urine from non-estrous females. The delay-of-maturation phenomenon in female mice is not affected by reproductive history, cross-fostering of pups, or varying the cagemates according to whether they are sibs or nonsibs. Taken together these and previous findings suggest that female mice excrete, in their urine, a series of chemicals which act as signals regarding the adequacy of reproductive conditions.