Fig. 8. p27 expression is arrested in oocyte nuclei of Zp3-Foxo3a Tg mice. Ovaries from 8- and 20-day-old WT mice and 20-day-old Tg mice were collected for immunohistochemistry for p27. (A) In 8-day-old WT mice (WT PD8), p27 was expressed in the nuclei of oocytes from primary/secondary (large arrows) and primordial follicles (small arrow), and also in the granulosa cells of these follicles (yellow arrows). (B) In the follicles of 20-day-old WT mice (WT PD20), p27 was only found to be expressed in the proliferating granulosa cells (yellow arrow), but not in oocytes of the developing follicles (black arrows). (C) In the ovaries of 20-day-old Tg mice (Tg PD 20), however, there was still expression of p27 in the nuclei of the oocytes (yellow arrows). The experiments were repeated three times and representative results are shown.