Henery C C, Kaufman M H
Department of Anatomy, University Medical School, Edinburgh, Scotland.
Mol Reprod Dev. 1993 Mar;34(3):299-307. doi: 10.1002/mrd.1080340310.
A brief electric pulse often produces a high rate of activation of recently ovulated oocytes. Some other efficient parthenogenetic stimuli, such as alcohol, however, disrupt the spindle apparatus and increase the incidence of aneuploidy. In this paper, we have determined whether electroactivation per se increases the incidence of chromosomal segregation errors in haploid parthenogenones as evidenced at first cleavage mitosis. Superovulated F1 hybrid female mice were killed at 15.5, 18.5, 22.5, and 25 h after the HCG injection. Batches of 10-12 cumulus-denuded oocytes were transferred to an electroactivation chamber containing mannitol which was connected to a high voltage pulse stimulator and the pulse was triggered once. A high proportion of oocytes activated following this treatment, but only the single-pronuclear haploid parthenogenones were incubated overnight in medium containing colcemid, to determine the incidence of aneuploidy as evidenced at first cleavage mitosis. "Sham" electroactivation groups were also examined for evidence of activation and aneuploidy as described above. In these cases, cumulus-denuded oocytes were put through the electroactivation chamber but the pulse was not triggered. A further group of oocytes was studied to determine the effect of handling and exposure to hyaluronidase on activation frequency and parthenogenetic pathways. Finally, the spontaneous rate of aneuploidy was examined in fertilised embryos of F1 hybrid female mice x Rb(1.3)1Bnr male mice at first cleavage mitosis. The results show that single pulse electroactivation does not increase the level of aneuploidy in single-pronuclear parthenogenous compared to the "sham" group or the spontaneous rate observed in 1-cell fertilised embryos, nor does aneuploidy appear to increase with postovulatory age.(ABSTRACT TRUNCATED AT 250 WORDS)
短暂的电脉冲常常能使近期排卵的卵母细胞产生较高的激活率。然而，一些其他有效的孤雌生殖刺激因素，如酒精，会破坏纺锤体装置并增加非整倍体的发生率。在本文中，我们确定了电激活本身是否会增加单倍体孤雌生殖体中染色体分离错误的发生率，这在第一次卵裂有丝分裂时可以得到证明。超排的F1杂交雌性小鼠在注射人绒毛膜促性腺激素（HCG）后的15.5、18.5、22.5和25小时被处死。将10 - 12个去除卵丘的卵母细胞批次转移到含有甘露醇的电激活室中，该电激活室连接到高压脉冲刺激器，触发一次脉冲。经过这种处理后大量卵母细胞被激活，但只有单核单倍体孤雌生殖体在含有秋水仙酰胺的培养基中孵育过夜，以确定在第一次卵裂有丝分裂时出现的非整倍体发生率。“假”电激活组也按照上述方法检查激活和非整倍体的证据。在这些情况下，去除卵丘的卵母细胞通过电激活室，但不触发脉冲。研究了另一组卵母细胞，以确定操作以及暴露于透明质酸酶对激活频率和孤雌生殖途径的影响。最后，在F1杂交雌性小鼠与Rb(1.3)1Bnr雄性小鼠受精胚胎的第一次卵裂有丝分裂时检查非整倍体的自发率。结果表明，与“假”激活组或在1细胞期受精胚胎中观察到的自发率相比，单脉冲电激活不会增加单核孤雌生殖体中的非整倍体水平，非整倍体似乎也不会随着排卵后年龄的增加而增加。（摘要截短于250字）
