REGULATION OF MEIOTIC METAPHASE BY A CYTOPLASMIC MATURATION-PROMOTING FACTOR DURING MOUSE OOCYTE MATURATION
REGULATION OF MEIOTIC METAPHASE BY A CYTOPLASMIC MATURATION-PROMOTING FACTOR DURING MOUSE OOCYTE MATURATION
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DOI：
10.1016/0012-1606(88)90135-2
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发表时间：
1988-04-01
影响因子：
2.7
通讯作者：
KISHIMOTO, T
中科院分区：
文献类型：
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作者：
HASHIMOTO, N;KISHIMOTO, T
在小鼠卵母细胞成熟过程中，研究了细胞质成熟促进因子（MPF）活性的调节。小鼠MPF活性是通过小鼠卵母细胞胞浆微注射诱导未成熟海星卵母细胞成熟的能力来确定的。MPF最初出现在生发囊泡破裂（GVBD）时，其活性波动与减数分裂周期完全一致，在每个中期达到峰值，在第一极体发射时几乎消失。环己亚胺既不影响MPF的初始表现，也不影响GVBD。然而，在环己亚胺的存在下，减数分裂纺锤体不形成，MPF消失，尽管染色体仍然凝聚。去除环己亚胺后，MPF再次出现，随后是第一个中期和随后的极体发射。最后减数分裂周期进入第二中期。因此，对于MPF的出现，在第一中期之前有一个关键时期，之后需要蛋白质合成。在细胞松弛素D或秋胶酸存在的情况下，MPF活性保持在较高水平。在细胞松弛素处理的卵母细胞中加入环已酰亚胺，减数分裂周期在第一个中期停止，导致MPF水平降低，随后染色体向两极移动，在那里它们去致密，形成两个核样结构。因此，MPF的消失可能会引发中期到后期的转变。此外，详细的细胞学检查显示，细胞松弛素处理的卵母细胞中的染色体是单价的，而仅用环己亚胺处理的卵母细胞是二价的，这表明突触的解离是MPF消失后染色体去浓缩的先决条件。在所有这些方面，强积金似乎是一个隐喻的促进因素，而不仅仅是一个成熟的促进因素。
During mouse oocyte maturation the regulation of the activity of a cytoplasmic maturation-promoting factor (MPF) was examined. The mouse MPF activity was determined based on its ability to induce maturation in immature starfish oocytes after microinjection with the cytoplasma from mouse oocytes. MPF appeared initially at germinal vesicle breakdown (GVBD), and its activity fluctuated in exact correspondence with meiotic cycles, reaching a peak at each metaphase and almost disappearing at the time of emission of the first polar body. Cycloheximide affected neither the initial MPF appearance nor GVBD. Thereafter, however, in the presence of cycloheximide the meiotic spindle was not formed and MPF disappeared, although the chromosomes remained condensed. After removing cycloheximide, MPF reappeared and was followed by th first metaphase and subsequently by polar body emission. Finally the meiotic cycle progressed to the second metaphase. Thus, for the appearance of MPF, there is a critical period shortly before the first metaphase, after which protein synthesis is required. In the presence of either cytochalasin D or colcemid, MPF activity remained at elevated levels. Addition of cycloheximide to such cytochalasin-treated oocytes, in which the meiotic cycle was arrested at the first metaphase, caused the MPF levels to decrease and was followed by movement of chromosomes to both poles where they decondensed and two nucleus-like structures wer formed. Thus, the disappearance of MPF may initiate the metaphase-anaphase transition. Furthermore, detailed cytological examination revealed that chromosomes in cytochalasin-treated oocytes were monovalent while those treated only with cycloheximide was divalent, suggesting that dissociation of the synapsis is a prerequisite for chromsome decondensation after the disappearance of MPF. In all these repects, MPF seems to be a metaphose-promoting factor rather than just a maturation-promoting factor.