O'Neill G T, McDougall R D, Kaufman M H
Department of Anatomy, University Medical School, Edinburgh, Scotland.
Gamete Res. 1989 Mar;22(3):285-99. doi: 10.1002/mrd.1120220306.
A high frequency of parthenogenetic activation occurs when ovulated mouse oocytes are briefly exposed to a dilute solution of ethanol in vitro. Cytogenetic analyses of parthenogenones at metaphase of the first cleavage division have confirmed that parthenogenetic activation, per se, does not increase the incidence of chromosome segregation errors during the completion of the second meiotic division. Ethanol-induced activation, however, significantly increases the incidence of aneuploidy. The ultrastructural changes that occur in the morphology and organization of the second meiotic spindle apparatus in ethanol- and hyaluronidase-activated oocytes is reported here. Abnormalities in the arrangement of microtubule arrays and chromosome position were principally observed in ethanol-activated oocytes at anaphase and telophase of the second meiotic division, but were only rarely observed in hyaluronidase-activated oocytes. It is proposed that the abnormalities in spindle morphology and chromosome displacement observed in ethanol-activated oocytes represent the initial events that lead to chromosome segregation errors following exposure to this agent.
当排卵后的小鼠卵母细胞在体外短暂暴露于稀释的乙醇溶液中时，会出现高频的孤雌激活现象。对第一次卵裂中期孤雌胚的细胞遗传学分析证实，孤雌激活本身并不会增加第二次减数分裂完成过程中染色体分离错误的发生率。然而，乙醇诱导的激活会显著增加非整倍体的发生率。本文报道了乙醇和透明质酸酶激活的卵母细胞在第二次减数分裂纺锤体装置的形态和组织中发生的超微结构变化。在第二次减数分裂后期和末期的乙醇激活卵母细胞中，主要观察到微管阵列排列和染色体位置的异常，但在透明质酸酶激活的卵母细胞中很少观察到。有人提出，在乙醇激活的卵母细胞中观察到的纺锤体形态和染色体位移异常代表了接触该试剂后导致染色体分离错误的初始事件。
