Evaluation of the Follicular Growth during Mouse Ovarian Culture in Medium Supplemented with Different Doses of Growth Differentiation Factor 9B

Growth differentiation factor 9B (GDF9B) is an oocyte-derived growth factor. This protein is essential for the development of ovarian follicles and acts mainly by binding to its receptor on the surface of granulosa cells. The effect of GDF9B on the growth of follicles in various developmental stages، particularly primordial and primary follicles، is unknown. Thus the aim of this study is to investigate these effects after mouse whole ovarian culture. Female NMRI mice (14 day-old) were sacrificed by cervical dislocation Subsequently their collected ovaries were cultured in α-MEM basic medium (control group) and medium supplemented with different doses of recombinant GDF9B (10، 20، 40 ng/ml) for seven days in 5% CO2 and 37°C. At the end of the culture period، serial sections of ovaries were prepared and stained with hematoxylin and eosin. The follicles were counted in the primordial، primary، preantral and antral stages and compared among the different groups. In GDF9B supplemented groups the percentage of antral follicles significantly increased whereas the percentage of preantral follicle decreased when compared with the control group. However there were no significant differences between the percentage of primordial and primary follicles in all supplemented GDF9B (10، 20، 40 ng/ml) groups and the control. Overall، this study showed that GDF9B stimulated the growth of preantral follicles to the antral stage. However this factor did not have a remarkable effect on the growth of primordial and primary follicles.