Abstract
The timing, duration and possible enhancement effects of group contact on the delay of sexual maturation produced in prepubertal female house mice by urine from grouped females were examined. One or 3 days of pheromone stimulation at specified ages during the first 2 wk after weaning was not sufficient to delay puberty in females caged singly. Phernomone treatment for 7 days, beginning during the first week after weaning, significantly delayed the onset of first vaginal estrus relative to control females treated with water. Both the timing and duration of pheromone stimulation appear to be critical factors affecting pheromone-induced delay of sexual maturation. Mean ages at first estrus for females housed with a group of 7 other females, for 3 or 7 days at specified ages during the first 2 wk after weaning, did not differ from mean ages recorded with urine stimulation only. Contact with other females does not appear to alter or enhance the delay-of-maturation effect achieved with urine stimulation. In all these respects the maturation-delay pheromone of grouped female mice appears to differ from the puberty-accelerating pheromone of male mice.