Calcium-independent, meiotic spindle-dependent metaphase-to-interphase transition in phorbol ester-treated mouse eggs.
Calcium-independent, meiotic spindle-dependent metaphase-to-interphase transition in phorbol ester-treated mouse eggs.
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DOI：
10.1006/dbio.1995.1264
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发表时间：
1995-09
影响因子：
2.7
通讯作者：
R. Moses;Douglas Kline
中科院分区：
文献类型：
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作者：
R. Moses;Douglas Kline
在减数分裂中期II停滞的小鼠卵，由于受精或暴露于孤雌生殖剂（例如佛波酯佛波醇肉豆蔻酸酯乙酸酯（PMA））而形成原核。卵暴露于微管抑制剂秋水仙胺引起减数分裂纺锤体的消失，并阻止PMA诱导的中期释放。然而，秋水仙胺和PMA处理的鸡蛋，缺乏纺锤体形成细胞核时，另外与蛋白质合成抑制剂放线菌酮或蛋白激酶抑制剂6-dimethylaminopurine处理。为了防止细胞内钙浓度（[Ca 2 +]i）的增加，将卵暴露于钙螯合剂1，2-双（邻氨基苯氧基）乙烷-N，N，N 'N'-四乙酸（BAPTA）的细胞渗透性乙酰氧基甲酯（AM）形式。BAPTA AM和PMA处理的卵中45%形成核，BAPTA AM、PMA和放线菌酮处理的卵中90%形成核，表明[Ca 2 +]i的增加对于PMA诱导的中期释放不是必需的。卵细胞内[Ca ~（2+）]i在PMA作用下不发生变化，这进一步证明PMA激活卵细胞而不升高[Ca ~（2+）]i。
Mouse eggs, arrested at metaphase II of meiosis, form pronuclei as a result of fertilization or exposure to parthenogenetic agents, such as the phorbol ester phorbol myristate acetate (PMA). Exposure of eggs to the microtubule inhibitor colcemid caused the disappearance of the meiotic spindle and prevented the PMA-induced release from metaphase. However, colcemid- and PMA-treated eggs which lacked spindles formed nuclei when treated in addition with the protein synthesis inhibitor cycloheximide or the protein kinase inhibitor 6-dimethlyaminopurine. To prevent an increase in intracellular calcium concentration ([Ca2+]i), eggs were exposed to the cell permeant acetoxymethyl ester (AM) form of the calcium chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid (BAPTA). Nuclei formed in 45% of eggs treated with BAPTA AM and PMA and in 90% of eggs treated with BAPTA AM, PMA, and cycloheximide, suggesting that an increase in [Ca2+]i is not necessary for the PMA-induced release from metaphase. The [Ca2+]i did not change in eggs which formed nuclei in response to PMA, providing additional evidence that PMA activates eggs without elevating the [Ca2+]i.