**Figure 3.** **The activation of PFs by eNOS depended on cGMP/PKG.** (**A**, **B**) Ovaries at 1 dpp were treated with the vehicle, SN (100 μM), ODQ (1 μM), SN + ODQ, NM (1 mM), YC (10 μM) or NM + YC for six days (n=6). (**A**) The ovarian morphology was analyzed after hematoxylin staining. (**B**) The numbers of PFs and GFs/the total number of follicles were analyzed. (**C**, **D**) Ovaries at 1 dpp were treated with the vehicle, YC (10 μM), KT (1 μM), YC + KT, ODQ (1 μM), 8Br (10 μM) or ODQ + 8Br for six days (n=6). (**C**) The ovarian morphology and (**D**) the numbers of PFs and GFs/the total number of follicles were analyzed. Scale bar, 40 μm. Different letters with the same color denote statistical significance at *p* < 0.01 (Red letters represent the proportions of PFs, while black letters represent the proportions of GFs).