利用超数排卵技术进行优化C57BL/6J小鼠的生物净化体系

Use of optimized superovulation conditions for C57BL /6J mouse purification

目的以近交系C57BL/6J小鼠为实验对象,通过注射不同剂量的孕马血清促性腺激素(PMSG)和人绒毛膜促进腺激素(hCG)对小鼠进行超数排卵、体外授精和胚胎移植,确定最佳超排剂量,从而完善以C57BL/6J小鼠为背景的转基因小鼠的生物净化体系。方法将5周龄的C57BL/6J雌鼠进行5 IU、10 IU、7.5 IU、15 IU四个剂量组的超数排卵,通过超数排卵与剖宫取胎、胚胎移植两种净化方法相结合,确定C57BL/6J小鼠的净化方法所需的最佳剂量。结果剖宫取胎方法中,注射5 IU剂量组的C57BL/6J小鼠超排后合笼见栓率最高,为(89.00±19.05)%,产仔数和见栓率与其它三组均差异不显著;胚胎移植方法中,10 IU剂量组平均卵母细胞数为30.33±0.89枚,平均体内2-细胞胚胎数为23.78±0.19枚,均显著高于其它三组。结论剖宫取胎法生物净化时,5 IU剂量组可以提高C57BL/6J小鼠的交配成功率;胚胎移植法生物净化时,10 IU剂量组可以获得最多的体内和体外2-细胞胚胎,为C57BL/6J小鼠最佳超排剂量。

Objective To define the best dose of PMSG/hCG for superovulation and optimize the biological purification system for genetic-modified mice of C57BL /6J background,we injected different dose of PMSG /hCG to promote superovulation,and carried out in vitro fertilization and embryo transplantation. Methods 5-week old female C57BL /6J mice were injected with 4 different doses（5 IU,7. 5 IU,10 IU and 15 IU,respectively） of PMSG /hCG. Then the mice were mated with wild type male mice and embryos were obtained by cesarean section. In another approach,oocytes of superovulated mice were fertilized in vitro and then transplanted into surrogate female mice.Results In the cesarean section group,the highest rate of pregnancy was 89. 00 ± 19. 05% in the 5 IU injection group. But the difference compared with other groups was not statistically significant. In the embryo transplantation group,the average number of oocytes from 10 IU injection group was 30. 33 ± 0. 89,and the average number of 2-cell embryo was 23. 78 ± 0. 19,significantly higher than those in the other three groups. Conclusions Administration of5 IU PMSG /hCG will improve mating efficiency in cesarean section-based purification of C57BL /6J mice. 10 IUPMSG /hCG is the best dose for superovulation of C57BL /6J mice. The number of 2-cell embryos is maximized when10 IU PMSG /hCG is used in the embryo transplantation.