FIGURE 5.

EGF treatment improves the activation and development of human follicles. (A) Histological and immunostaining detection to test the existence of primordial follicles in fresh human ovarian pieces before transplantation (green: DDX4, purple: FOXL2, blue: Hoechst, n = 5). (B) Detecting the effect of EGF on stimulating human dormant follicle activation. Human ovarian cortical pieces which contained a large number of primordial follicles were cut into small cubes (1 mm³) and incubated with or without EGF for 30 minutes in dishes, then the treated tissues were xenografted into the kidney capsule of ovariectomized SCID mice for further development. (C) After 2 weeks (30 ± 12% vs 10 ± 9%), 4 weeks (38 ± 10% vs 18 ± 10%) and 8 weeks (44 ± 15% vs 21 ± 10%) of in vivo development under kidney capsule, follicle counting showed a significantly increased proportion of growing follicles in EGF‐treated human ovarian pieces compared to that of the controls (n = 5 per group). (D) After 2 weeks of transplantation, secondary follicles with multilayer granulosa cells (arrowhead) were observed in EGF‐treated ovarian pieces, and only primary follicles were found in the control group (n = 5). (E) Preovulatory follicles were found in EGF‐treated ovarian pieces after 4 and 8 weeks of transplantation, whereas only the secondary follicles were found in the control group (n = 5). Data represent the mean ± SD of biological triplicate experiments. *P < .05, by two‐tailed unpaired Student's t test. Scale bars: 50 µm