小鼠电激活孤雌胚胎早期体内外发育能力的比较

Comparison of the early developmental ability between in vivo and in vitro produced mouse parthenogenetic embryos induced by electrical activation

目的探讨小鼠电激活孤雌胚胎的早期体内、外发育能力。方法 利用不同电脉冲参数和激活液对小鼠卵母细胞进行活化,观察激活后的小鼠孤雌胚体外发育状况和移植后的发育能力。结果非电解质激活液优于电解质液,脉冲强度、脉冲宽度和脉冲次数3个参数各自处于某一范围内时,他们之间存在某种相关性,降低其中1个参数可通过升高另外2个参数得到补偿,经筛选较适宜的电脉冲参数为:1.0 kV/cm、40μs、2 p,或者1.5kV/cm、30/μs、2 p,分别为74.65%和71.19%,体外囊胚发育率分别为43.40%和47.62%。电激活孤雌胚体外发育时序比正常胚胎慢,但囊胚细胞数与对照组差异不显著。它们经胚胎移植后,其中的一部分能够着床,但着床率仅为3.6%,极显著低于对照组(67%,P<0.01)。结论电刺激能够较好地模拟正常受精过程激活小鼠卵母细胞,但激活后的多数小鼠孤雌胚胎着床能力较低,不能够顺利着床。

Objective This study was aimed to investigate the early developmental ability between in vivo or in vitro produced mouse parthenogenetic embryos induced by electrical activation.Methods Using different electric pulse parameters and activation solutions to activate the mouse oocytes and to observe the in vitro developmental ability of these embryos and their evolving post-transplantation capacity.Results The non-electrolyte solution was superior to the electrolyte solution.Each parameter of their pulse intensity,pulse width and pulse frequency was suitable within a certain range.There were some compensated correlations among them： If a parameter was reduced,its reduction could be compensated by the other two parameters immediately.Therefore,the screened appropriate electrical pulse parameters were as following： 1.0 kV/cm,40 μs,2 p,or 1.5 kV/cm,30 μs,2 p.The activation rates were 74.65% and 71.19%,respectively,as well their in vitro blastocyst rates were 43.4% and 47.62%,respectively.In addition,the electrical activation sequence of those in vitro produced parthenogenetic embryos,seemed to be slower than that of normal ones,but the blastocyst cell number was not significantly different to that of the control group.The implantation rate of the parthenogenetic embryos was significantly lower than that of the control one（3.6% vs.67%,P0.05）.Conclusions The electrical stimulation can almost mimic the normal fertilization process of murine oocytes,but most of these parthenogenetic embryos can not successfully initiate the implantation.