The effect of follicle stimulating hormone and epidermal growth factor on the developmental capacity of in-vitro matured mouse oocytes

Abstract

This study investigates the effects of follicle stimulating hormone (FSH) or epidermal growth factor (EGF) on the development of mouse oocytes matured in vitro. The data show that addition of FSH or EGF does not significantly increase the proportion of oocytes maturing to metaphase II but does increase the ability of these oocytes to cleave to the 2-cell stage after fertilization. After transfer of 2-cell embryos to pseudopregnant recipients, 64-78% of the embryos implanted, which was significantly reduced compared to embryos from in-vivo matured controls (89%). Fewer fetuses at day 14 of gestation were produced from embryos derived from oocytes matured in basal conditions (26%), or in the presence of EGF (32%), compared to oocytes matured in vivo (64%) or in the presence of FSH (58%). Examination of polar bodies and pronuclei of oocytes matured in vitro suggests that an increase in the rate of triploidy may be partly responsible for the increased fetal loss after maturation in the absence of FSH. This study shows that the fertilization rate after in-vitro maturation can be improved by FSH and EGF and that subsequent embryonic development is improved specifically by FSH.