Effect of supplementation of leukemia inhibitory factor and epidermal growth factor on murine embryonic development in vitro, implantation, and outcome of offspring

Abstract

Objective To evaluate the supplementation of leukemia inhibitory factor (LIF) or epidermal growth factor (EGF) in a single culture system (IVF50) and a sequential culture system (IVF50-S2) to determine whether they had any additional benefit on embryo development and implantation. Design Prospective controlled animal study. Setting University research laboratory. Subject(s) Two-cell embryos from F1(CBA × C57BL) mice. Intervention(s) Embryos were randomly cultured in different growth factor-treated or untreated in vitro systems. Main outcome measure(s) Blastocyst formation and morphology, total cell numbers of day 5 blastocysts, birth rates, and characteristics of the offspring. Result(s) The beneficial effects of LIF or EGF on blastocyst development and morphology were observed only in IVF50 medium but not in sequential IVF50-S2 media. In addition, blastocysts generated from the LIF-supplemented cultures had higher total cell numbers and higher total birth rates after transfer compared to those from IVF50 medium alone. No significant effect on fetal development was observed but pups born after treatment in LIF-supplemented sequential cultures had prolonged gestation and increased birth weights. Conclusion(s) The beneficial effects of LIF and EGF on in vitro blastocyst development are mainly seen under suboptimal culture conditions (simple medium only) and their effects are masked in an improved in vitro system (sequential culture media). Supplementation of culture media with such factors, however, is still an attractive approach in enhancing embryo viability through increased total cell numbers. The beneficial effect of LIF in improving implantation and subsequent increased birth rates should be further explored.