| Effects of Pronuclear Age in Freezing Mouse Embryos on Survival and Development in Vitro after Cryopreservation. |
|
H S Kim, B Y Ryul, S K Oh, C S Suh, S H Kim, Y M Choi, J G Kim, S Y Moon, J Y Lee |
|
|
| Abstract |
|
This study was designed to evaluate the influence of pronuclear age on the survival and post-thawing development after cryopreservation of mouse embryos. Freezing and thawing were performed in the different pronuclear stages of mouse embryos after IVF. Embryos were obtained from F1 hybrid mice and classified into 4 groups according to the pronuclear stage (6hr, 9hr, 12hr and 15hr after insemination). Pronuclear ova were slowly cooled in a biological freezer using 1.5M 1,2-propanediol and 0.1M sucrose as cryoprotectant. Thawing was done at room temperature and 1,2-propanediol was removed by multi-step dilutions. Both frozen-thawed embryos and control fresh embryos were cultured in vitro in Ham's F-10 medium supplemented with 4mg/ml BSA. In control group, the development rate after 48hr was 99.3%, and the complete hatching rate after 144hr u a3 61.B%. In experimental groups, the survival rate after thawing was 95.4% in 6hr, 88.7% in 9hr, 75.2% in IBhr and 62.4% in 15hr after insemination, the development rate after 48hr was 61.1, 77.0, 67.0 and 79.6%, respectively, and the complete hatching rate after 144hr was 25.7, 43.7, 42.2 and 60.0%, respectively. The survival rate in 15hr was significantly lower(p<0.05) compared with other groups. In vitro development rates after 48hr were similar in all groups, but complement hatching rate was significantly lower (p<0.05) in 6hr group. In conclusion, cryopreservation of mouse pronuclear ova with 2 distinct pronuclear (9hr and 12hr groups) showed better results after thawing compared with early (6hr group) or late pronuclear ova just prior to cleavage (15hr group). |
|
PDF Links
Full text via DOI
Download Citation
