**Figure 4.** **The eNOS/cGMP/PKG pathway promoted oocyte FOXO3a translocation and granulosa cell proliferation during PF activation.** (**A**) Immunofluorescence staining of FOXO3a was performed in ovaries treated with the vehicle, SN (100 μM), NM (1 mM), YC (10 μM), ODQ (1 μM), 8Br (10 μM) or KT (1 μM) (n=6). Arrows indicate PFs and triangles indicate GFs. Scale bar, 40 μm. (**B**) The number of oocytes with cytoplasmic localization of FOXO3a (CL-FOXO3a)/the total number of oocytes was analyzed (n=8). (**C**) The number of PFs with CL-FOXO3a/the total number of PFs was analyzed in each group (n=8). (**D**) Ki67 staining was carried out in ovaries treated with the vehicle, SN (100 μM), NM (1 mM), YC (10 μM), ODQ (1 μM), 8Br (10 μM) or KT (1 μM) for six days. Scale bar, 40 μm. (**E**–**G**) Ki67-positive somatic cells in follicles were counted in all the groups (n=6). Different letters denote statistical significance at *p* < 0.01. * and ** denote statistical significance at *p* < 0.05 and *p* < 0.01, respectively.