Effect of growth factors on in vitro development of caprine preantral follicle oocytes

The objective of this work was to examine the effect of various growth factors including epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I), either individually or in association, in the presence of follicle stimulating hormone (FSH) on the in vitro growth and viability of caprine preantral follicle oocytes. Preantral follicles were disassociated enzymatically and mechanically from prepuberal caprine ovaries after the animals were anesthetically ovariectomized. In experiment, caprine preantral follicles in groups 1-4 were cultured in growth culture medium, growth culture medium+EGF, growth culture medium+IGF-I and growth culture medium+IGF-I+EGF, respectively, for 9 days. The results indicated that EGF (50 mg/l) increased the survival rate of oocytes, but decreased the growth rate of oocytes; IGF-I (100 mg/l) effectively maintained the survival of oocytes and stimulated their growth; IGF-I (100 mg/l) and EGF (50mg/l) in combination produced a higher effect on both of the survival and the growth rate of oocytes than IGF-I or EGF alone. Conclusively, the growth factors can effectively maintain the survival of caprine preantral follicle oocytes and regulated their growth in culture. EGF and IGF-I in association could synergically meliorate the culture system of caprine preantral follicle oocytes.