Effect of different concentrations of recombinant leukemia inhibitory factor on different development stage of mouse embryo in vitro

Purpose: To assess the influence of different concentrations of recombinant human leukemia inhibitory factor (LIF) on the in vitro development of mous e embryos. Methods: The 2- to 4-cell embryos of CB6F1 mice were cultured in the human tubal fluid (HTF) media containing different concentrations of LIF. Mouse e mbryos were divided into seven groups: (1) HTF; (2) 1500 IU/ml LIF; (3) 100 0 IU/ml LIF; (4) 750 IU/ml LIF; (5) 500 IU/ml LIF; (6) 250 IU/ml LIF; (7) 1 25 IU/ml LIF. The embryonic numbers of different stages including 5-8 cell, 9-16 cell, morula, blastocyst, and hatching blastocyst were recorded. Results: The percentage of early embryo stage (2-cell embryos to 6- to 16-c ell stages) in all groups were nonsignificantly different. There were highe r formation rates of preimplantation embryos (morula to hatching blastocyst ) in groups 2, 3, 4, and 5 than in groups 1, 6 and 7. Conclusions: LIF has positive effects on preimplantation embryo development and has nonsignificant influence on the early embryo development. The lowe st concentration of LIF which could provide the optimal embryo development is 500 IU/ml.