Effects of Rapamycin on Early Development of Mouse InVitroFertilized Embryos

This study was to explore the physiological function of rapamycin(RAPA),the specific inhibitor of mammalian target of rapamycin(mTOR),during early development of mouse embryos derived fromin vitro fertilization(IVF).Chemically defined medium with different concentrations of RAPA(the control group:0ng/mL;the treatment groups:0.1,1,10 and 100ng/mL)was used for embryo culture,and the in vitro cleavage rate,formation rate and quality of blastocysts(the number of inner cell mass(ICM)cell,trophectoderm(TE)cell and total cell)of the embryos were examined.Results were as follows.After 24 hours of embryos cultured,the cleavage rate was found no significant difference when RAPA added from the pronuclear stage embryos,but after 90-96hours of embryos cultured,the blastocyst rate of 100ng/mL group was significantly lower than that of the other groups(including the control group)(P0.05)when RAPA added both from the pronuclear stage embryos and 2-cell stage embryos.The result of blastocyst cell counting showed,the 100ng/mL group was found obviously decreased compared to the control group(P0.05)on the number of ICM cell,TE cell and total cells,which indicated that the quality of blastocyst development was affected.Our research suggests the early development of in vitro mouse embryo was restrained by RAPA at the beginning concentration of 100ng/mL,and the mTOR signal pathway within the maintenance of mouse blastocyst formation is essential.