Figure 3.

Ovarian histologic sections illustrating decreasing primordial follicle populations with age. (A) Neonatal (6 d) vervet monkey shows a myriad of primordial follicles characterized by a flattened single granulosa cell layer and occasional apoptotic oocytes and mitotic oocytes. (B) Reproductive-age (9 y) animal demonstrates abundant primordial follicles (thin arrow), primary follicles (arrowhead), secondary follicles (thick arrow), and antral follicles (not shown). (C) Aged (23 y) vervet monkey has paucity of all follicle types in the ovarian cortex. Bar, 50 μm.