Effect of vitrification on in vitro development and imprinted gene Grb10 in mouse embryos
Vitrification of embryos is a routine procedure in IVF (in vitrofertilization) laboratories. In the present study, we aimed to investigate the effect of vitrification on mouse preimplantation embryo developmentin vitro, and effect on the epigenetic status of imprinted geneGrb10in mouse embryos. The blastocyst formation rate for vitrified 8-cell embryos was similar to the non-vitrified 8-cell embryos, whereas the blastocyst hatching rate was lower than that of the non-vitrified group. The expression level ofGrb10major-type transcript decreased significantly in vitrified blastocysts compared with non-vitrified andin vivoblastocysts. Moreover, the global DNA methylation level in 8-cell embryos and blastocysts, and the DNA methylation at CpG island 1 (CGI1) ofGrb10in blastocysts were also significantly decreased after vitrification.In vitroculture condition had no adverse effect, except for on the DNA methylation inGrb10CGI1. These results suggest that vitrification may reduce thein vitrodevelopment of mouse 8-cell embryos and affect the expression and DNA methylation of imprinted geneGrb10.