Effects of diethylstilbestrol on ovarian follicle development in neonatal mice

Previous results show that diethylstilbestrol (DES) causes polyovular follicles through estrogen receptor (ER) β and increases the number of follicles, suggesting that DES might affect follicular growth and development. Effects of neonatal DES exposure on follicle development were precisely examined in the ovaries of C57BL/6J and ERβ knockout (βERKO) mice. In the DES-exposed C57BL/6J mice, both primary follicle (PmF) progression from primordial follicles at 5 days of age and secondary follicle (SF) progression from PmFs at 10 days of age were delayed as compared with those in the oil-exposed controls. These results indicate that DES may suppress follicle development in neonatal mouse ovaries. DES exposure also decreased the number of follicles in 5-day-old C57BL/6J, WT and βERKO mice, suggesting that DES inhibits follicle formation and development through ERα in the neonatal mouse ovaries.