Leukemia Inhibitory Factor (LIF) Improves and Prolongs the Development of Parthenogenetic Mouse Embryos

We studied the effect of the growth factor LIF on the development of parthenogenetic mouse embryos (CBA × C57BL/6)F1. LIF was added to the culture medium at 10, 50, 100, and 250 ng/ml at the morula stage and parthenogenetic embryos were cultured in vitro until the late blastocyst stage and then transplanted in the uterus of pseudopregnant females, which were then sacrificed on day 12 of pregnancy. All the LIF doses used improved the development of parthenogenetic mouse embryos at the preimplantation stages and increased the amount of blastocysts by 15%, on average, as compared to the control. LIF at 50 and 100 ng/ml increased approximately twice the number of embryos that reached the somite stages. Some of them reached the stage of 32–45 somites and had fore and hind limb buds. No such embryos were found in the control. Well formed placenta was observed in 6% of the embryos treated with LIF and the most pronounced effect was recorded at 100 ng/ml. The data we obtained suggest that exogenous LIF can improve pre- and postimplantation development of parthenogenetic mouse embryos due, possibly, to increased survival rate of embryonic stem cells derived from the inner cell mass of blastocysts. LIF improves not only the development of the parthenogenetic embryoper se, but also the formation of its extraembryonic envelopes, which leads to the development of a larger placenta in LIF-treated parthenogenetic embryos, as compared to the control.