【Animal Modeling】-Comparison of in vivo and in vitro development potential between dormant mouse embryos and normal embryos after freezing and thawing

  Purpose: To test the quality and in vitro and in vivo development potential of dormant mouse embryos after freezing and thawing, and to provide necessary reference for the production and application of embryo dormancy technology.

  Method: The normal incubation period embryos and dormant embryos were frozen using conventional freezing methods, and then the in vitro resuscitation and embryo transfer experiments were performed respectively. Then the dormant embryos before and after freezing and thawing were compared with the normal incubation period by the double fluorescent staining method. The embryos were counted and the quality changes of the two embryos before and after freezing and thawing were observed.

  Results: The freezing and thawing recovery rate and development rate of dormant embryos were significantly higher than hatching embryos (72.1% vs 50.2%, P<0.01; 94.2% vs 73.9%, P<0.01). The pregnancy rate of dormant embryos was transferred Significantly higher than hatching embryos (40.8% vs 30.1%, P <0.05). The number of cells in the inner cell mass of dormant embryos was significantly higher than that of hatching embryos (27.83 vs 19.53, P <0.05), and the number of trophoblast cells was not different. Significant. The number of inner cell masses and the number of trophoblast cells of dormant embryos after freeze-thaw culture were significantly higher than those of hatched embryos (25.18 vs 14.68, P<0.05; 114.09 vs 73.88, P<0.05).

  Conclusion: The embryo quality and in vitro and in vivo development potential of dormant mouse embryos after freezing and thawing are better than mouse embryos during normal incubation period.