Embryonic survival, development and cryoinjury of repeatedly vitrified mouse preimplantation embryos.

OBJECTIVE: The aim of this study is to investigate the embryonic survival, development, and expressions of cryoinjury- or antioxidant-related genes in once, twice, or three-time vitrified mouse preimplantation embryos. Study desisgn: Six hundred 8-cell stage embryos were obtained from 60 female mice and randomly assigned to control and three experimental groups. Embryos were vitrified by indirect methods The developmental outcomes such as survival rate, blastocyst-forming rate, and the percentage of hatching/hatched blastocyst were assessed. The cell numbers of hatching/hatched blastocyst were counted after nuclear staining. From hatching/hatched blastocysts, the mRNA expressions for Cirbp, Casp3, Sod1, Gpx3, and Cat were quantified by real-time quantitative RT-PCR.

RESULTS: In once, twice, or three-time vitrified mouse 8-cell stage embryos, survival rates, blastocyst-forming rates, the percentages of hatching/hatched blastocyst, and the cell counts were all similar when compared with non-vitrified control group. The mRNA expression levels of Cirbp, Casp3, Sod1, Gpx3 and Cat were not affected.

CONCLUSION: Repeatedly vitrified mouse 8-cell stage embryos well developed up to blastocyst stage without cryoinjury and without decrease of antioxidant-related genes.