小鼠卵母细胞去核方法的研究

A STUDY ON THE TECHNIQUES FOR ENUCLEATION OF THE MOUSE OOCYTE

用 McGrath 和 Solter 的去核方法和改进的胚胎染色体制备技术,研究小鼠卵母细胞去核的基本方法及吸出的胞质量和极体的有无对去核率的影响。实验表明:(1)小鼠卵母细胞透明带弹性很差,去核操作成功率仅53.8%;(2)制备卵母细胞染色体,无需用秋水仙素等处理,直接经2～3min 低渗处理便可使第2次减数发裂中期染色体充分展开;(3)小鼠卵母细胞去核时抽1/4胞质的染色体全部去除率(49%)和抽1/3胞质的(54%)差异未达到显著水平(P>0.05);(4)注射 HCG 后15～16h 获取的小鼠卵母细胞,只有1/3左右具有明显的第1极体;抽取无极体卵母细胞之卵周隙较大一侧的细胞质,去核率与见极体卵母细胞的无明显差异。

The effects of sucking different amounts of cytoplasm and with or without the first polarbody as indication during enucleation on the enucleation rate in the mouse oocyte were stud-ied by means of McGrath and Solter's technique for enucleation and a modified technique forchromosome preparation.The main results are as follows:1.The oocyte was more difficult toenucleate than the zygote in the mouse due to the softness of the zona and only 53.8% of theoocytes survived the manipulation;the difference in survival rate between the oocytes fromwhich 1/4 or 1/3 cytoplasm was removed was not significant.2.The metaphaseⅡchromosomes were well spread by a short-term(2～3 min)hypotonic treatment and atwo-step fixation process.3.Although the complete-enucleation rate(all the chromosomesremoved)of sucking 1/3 cytoplasm from the oocyte(54%)was not significantly greaterthan that of sucking 1/4 cytoplasm(49%),the enucleation rate of the former(71.5%)be-came remarkably higher(P<0.01)than that of the latter(59%)when the half-enucleatedoocytes(with some chromosomes left)were included.4.Only about 1/3 of the oocytes col-lected 15～16 hours after HCG had a notable FPb,and a complete-enucleation rate of 50%was obtained when the oocytes without FPb were enucleated by sucking the cytoplasm fromthe PVS-wider side,and this was not significantly different from that obtained in the oocyteswith FPb.