Monoclonal antibodies against epidermal growth factor prevent outgrowth of mouse embryos in vitro

The necessity of epidermal growth factor (EGF) in the process of mouse embryo development and outgrowth in vitro was studied. Mouse 4-cell stage embryos were cultured up to spreading stage (outgrowth) in human tubal fluid (HTF) medium alone (control) or with 10 ng/ml EGF and 1:250 diluted monoclonal antibodies against EGF (study groups). Hatching and outgrowth were significantly increased up to 60.9 and 52.4% respectively, while in the control only 33.7 and 20.4% reached hatching and outgrowth respectively. Moreover monoclonal antibodies against EGF significantly inhibited embryo development (P < 0.01). Only 5.8% of the embryos reached the hatching stage and none of them reached the spreading stage. Our results show that EGF is probably involved in the modulation of early embryonic growth and in the initiation of implantation.