Parameters of pubertal onset in WT, Fgfr1+/−, Fgf8+/−, and Fgfr1+/−/Fgf8+/− female mice. A) Age of VO. B) Time between VO and first estrus. Different letters represent significant differences (P < 0.05). n = 6, 8, 5, and 10 for WT, Fgfr1+/−, Fgf8+/−, and Fgfr1+/−/Fgf8+/− mice, respectively.