Effect of density, duration of grouping and age of urine stimulus on the puberty delay pheromone in female mice.

The ability of urine from female mice to delay puberty in test females was directly related to the density and duration of grouping of females. When females were removed from group housing their urine lost its ability to delay puberty within 10 days. No interactive effects were observed between duration and density of grouping on the onset of pheromone release after grouping or on the persistence of pheromone release after re-isolation. Urine from grouped females lost its ability to delay puberty in test females after 7 days of exposure to air.