两种玻璃化胚胎冷冻方法对不同品系小鼠胚胎冷冻效果比较

Comparison of two vitrification-cryopreservation methods of embryos of various mouse strains

目的探讨EFS和DAP两种玻璃化冷冻方法对不同品系小鼠胚胎冷冻的效果。方法 6个品系小鼠(KM、ICR、BALB/c、C57BL/6J、OB/OB、LAP/rtTA0F59)的2-cell胚胎分别用EFS和DAP两种玻璃化冷冻方法进行冷冻和复苏,比较两种冷冻方法的胚胎复苏率和着床率。结果 6个品系小鼠冷冻胚胎EFS方法的平均复苏率为69.97%(47.9%～83.6%),DAP方法的平均复苏率47.23%(26.3%～76.7%),EFS方法明显优于DAP方法。其中KM、ICR和BALB/c小鼠EFS方法的冷冻复苏率显著高于DAP方法(P<0.01);冻融胚胎移植后EFS方法的平均着床率27.23%(1.75%～45.0%),DAP方法的平均着床率31.43%(7.0%～46.3%)。除KM、ICR小鼠外,其他4个品系小鼠的着床率DAP方法高于EFS方法。结论 KM和ICR远交群小鼠胚胎适合用EFS方法冷冻保存;C57BL/6J、OB/OB、LAP/rtTA0F59三个品系小鼠DAP方法优于EFS方法,但差异不大;BALB/c小鼠两种玻璃化冷冻方法的冻融胚胎着床率均较低,需进一步研究。

Objective To compare the effect of two vitrification-cryopreservation methods of embryos of several mouse strains. Methods The two-cell embryos from six mouse strains （KM, ICR, BALB/c, C57BL/6J, OB/OB, LAP/ rtTAOF59） were cryopreserved and thawed, using EFS and DAP eryoprotectants, respectively. The recovery rate in vitro and implantation rate in vivo were determined to evaluate the efficacy of the two methods. Results The average post-thaw survival rates of the embryos of different strains preserved in EFS were 69.97% （47.9% to 83.6% ） , and preserved in DAP 47.23% （26. 3% to 76. 7% ）. After 2-cell embryos were transferred to the oviducts of pseudopregnant recipient in all the strains, the implantation rates of EFS-vitrified embryos were ranged from 1.75% to 45.0% （ average 27.23% ） and ofDAP-vitrified embryos from 7.0% to 46. 3% （average 31.43% ）. With the respect of recovery rate, EFS was preferred to DAP. No significant differences （P 〉 0. 05） were found between the implantation rates of EFS and DAP in KM and ICR strains. But the implantation rates of BALB/c, C57BL/6J, OB/OB, and LAP/rtTAOF59 mouse embryos in EFS were higher than those in DAP, respectively. Conclusions EFS cryoprotectant is suitable for both the KM and ICR mouse embryos vitrification-cryopreservation. DAP is somehow better than EFS for cryopreservation of C57BL/6J, OB/OB and LAP/rtTAOF59 mouse embryos, but with a non-significant difference between the two cryoprotectants. Both EFS and DAP show a rather low implantation rate of the BALB/c mouse embryos, therefore, further studies are needed to improve this issue.