Male urine fails to induce puberty acceleration in cGαo-/-females. (A,B) Puberty acceleration is measured as uterine to body mass ratio increase after seven-day exposure to male urine. (A) Dissected uteri from 29-day old B6, cGαo+/-aand cGαo-/- female mice unstimulated (top) and exposed to male urine (bottom). Scale bar, 5 mm. (B) Male urine exposure results in an increase in uterine mass in B6 and cGαo+/- controls but not in cGαo-/- females (analysis of variance (ANOVA): F2,80 = 5.4, P <0.01; LSD: ***P <0.001 (B6), *P <0.05 (cGαo+/-), non-significant (ns) P = 0.6 (cGαo-/-)). (C) Delayed puberty in cGαo-/- females. Average vaginal opening (ANOVA: F2,33 = 7.34, P <0.005; LSD: ***P <0.001 (B6), *P <0.05 (cGαo+/-)) and time of the first estrus (ANOVA: F2,30 = 9.54, P < 0.005; LSD: ***P < 0.001 (B6), **P <0.005 (cGαo+/-)) were analyzed. No significant differences between B6 and cGαo+/- controls were found (LSD: vaginal opening, P = 0.42; first estrus, P = 0.63). (D) Comparison of cumulative percentage of vaginal opening between the three genotypes. cGαo-/- (black circles) mice needed three to four days longer than B6 (white circles) or cGαo+/- (triangles) control mice to reach a 100% value. Number of tested animals per group is indicated in brackets.