FIG. 1.

The level of maternal and neonatal serum E₂ and FSH and the expression of Fshr in the fetal ovary during the time of primordial folliculogenesis. A) After birth, neonatal levels of E₂ dropped rapidly within 3 days and then increased starting on day 4. In contrast, FSH levels increased dramatically from the day of birth to 3 days after birth. Both E₂ and FSH levels increased by 7 days after birth. B) The expression of Fshr mRNA was detectable in the neonatal ovary and increased significantly within the first 3 days after birth. Letters indicate statistically significant changes between each time point (P < 00.05). DOB, day of birth; NB, newborn.