A CYTOPLASMIC CLOCK WITH THE SAME PERIOD AS THE DIVISION CYCLE IN XENOPUS EGGS
A CYTOPLASMIC CLOCK WITH THE SAME PERIOD AS THE DIVISION CYCLE IN XENOPUS EGGS
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DOI：
10.1073/pnas.77.1.462
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发表时间：
1980-01-01
期刊：
影响因子：
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通讯作者：
KIRSCHNER, M
中科院分区：
文献类型：
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作者：
HARA, K;TYDEMAN, P;KIRSCHNER, M
在大多数物种中，细胞周期在未受精卵中停滞。受精后，细胞周期重新建立，并发生一系列快速分裂。在非洲爪蟾的第一次卵裂之前，卵的皮质会发生收缩，称为表面收缩波，可以通过延时摄影来观察。这种收缩波以圆周方式从动物极传播到赤道。通过抗有丝分裂药物处理防止卵裂的卵子会经历一系列周期性的表面收缩波，其时间与未经处理的卵子的卵裂周期同步。人工激活的卵子可能由于缺乏功能中心粒而无法分裂，也会经历相同的周期性收缩。周期波不需要核材料，因为通过收缩受精卵产生的分离的卵碎片仍然经历与分裂有核碎片相同周期的收缩波。在没有任何核物质或中心粒的情况下，细胞周期的一些表达仍然存在，这表明脊椎动物卵的细胞质或皮层中存在生物钟，这可能与细胞周期的计时有关。
In most species the cell cycle is arrested in the unfertilized egg. After fertilization the cell cycle is reestablished and a rapid series of cleavages ensues. Preceding the 1st cleavage in Xenopus the egg undergoes a contraction of its cortex, called the surface contraction wave, which can be visualized by time-lapse cinematography. This wave of contraction is propagated in a circular manner from the animal pole to the equator. Eggs prevented from cleaving by treatment with antimitotic drugs undergo a sequence of periodic surface contraction waves timed with the cleavage cycle in untreated eggs. Artificially activated eggs, which fail to cleave presumably for lack of a functioning centriole, undergo the same periodic contractions. No nuclear material is required for the periodic waves because a separated egg fragment, produced by constricting a fertilized egg, still undergoes contraction waves with the same period as the cleaving nucleated fragment. Some expression of the cell cycle persists in the absence of any nuclear material or centrioles, suggesting that a biological clock exists in the cytoplasm or cortex of vertebrate eggs, which may be involved in timing the cell cycle.