Figure 1.

Lhb and Fshb mRNA levels were higher in females than males at PND0, but gonadotrope cell number was the same. Females showed elevated levels of Lhb and Fshb compared with males, but levels of transcription factors Foxl2, Egr1, and Nr5a1 were the same between sexes, and there was a significant but small difference in Gnrhr (n = 10–15) (A). Immunohistochemistry at PND0 with LHβ marked gonadotrope cells (magnification, ×200) in males (B) and females (C). Cell counts showed that there were no differences in gonadotrope cell number (n = 4) (D). Scale bar, 50 μm. *, P = .05.