Fig. 6.

In vitro activation of primordial follicles in neonatal or adult ovaries by short-term treatment (30 min) with CDC42 activator. The mouse ovaries were collected at 6 or 35 dpp (age of adult). Six dpp intact ovaries or 35 dpp ovarian pieces were cultured in vitro. a, b After 30 min of CDC42 activator treatment followed by 12 h of drug-free culture in vitro, the phosphorylation of FOXO3a and AKT in ovaries was significantly increased in both 6 dpp ovaries (a) and 35 dpp ovaries (b). c After CDC42 activator treatment, FOXO3a translocated to the cytoplasm in most oocytes in the ovarian cortex of 6 dpp ovaries (arrowheads) compared with control groups (arrows). d, f After 30 min of CDC42 activator treatment, intact ovaries at 6 dpp or fragmented ovaries at 35 dpp were immediately transplanted under the kidney capsules of ovariectomized adult hosts. After 2 weeks of in vivo development, the cluster of primordial follicles was hardly observed in cortex of both 6 dpp (d) and 35 dpp (f) ovaries after CDC42 activator treatment. e, g Follicle counting results showed the distribution of follicles after treatment with or without CDC42 activator in ovaries. The proportion of primary, secondary, and antral follicles was significantly increased in activator-treated ovaries compared to control groups (Additional file 10: individual data values). The experiments were repeated at least three times, and representative images are shown. Scale bars, 50 μm