Intracellular pH shift leads to microtubule assembly and microtubule-mediated motility during sea urchin fertilization: correlations between elevated intracellular pH and microtubule activity and depressed intracellular pH and microtubule disassembly.
Intracellular pH shift leads to microtubule assembly and microtubule-mediated motility during sea urchin fertilization: correlations between elevated intracellular pH and microtubule activity and depressed intracellular pH and microtubule disassembly.
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发表时间：
1985
影响因子：
6.6
通讯作者：
G. Schatten;T. Bestor;R. Balczon;J. Henson;H. Schatten
中科院分区：
文献类型：
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作者：
G. Schatten;T. Bestor;R. Balczon;J. Henson;H. Schatten
研究人员研究了海胆 Lytechinus variegatus 和 Arbacia punctulata 受精期间卵内微管介导运动的调节与细胞内 pH (pHi) 变化的关系，这种变化发生在卵激活的离子序列期间。通过抗微管蛋白免疫荧光显微镜检测精子紫苑和有丝分裂器形成过程中的微管组装，并通过延时视频微分干涉对比显微镜研究微管介导的精子和卵细胞核的迁移。通过对作为荧光素二乙酸酯掺入的细胞质荧光素进行荧光分析来验证细胞内 pH 值的操纵。操纵卵激活的离子序列i)以阻止受精时的pHi变化或将受精卵的pHi降低至未受精值，ii)人为地将未受精卵的pHi升高至受精值，以及iii)人为地升高或允许受精卵中的正常pHi变化，其中先前防止了受精时的pHi变化。 pHi 变化被抑制的受精卵不会组装微管或进行正常的微管介导的运动。在受精卵中，在精子紫苑组装后，pHi 降低至未受精水平，没有检测到任何运动。如果稍后允许细胞内 pH 值升高，则会发生导致分裂和发育的正常运动事件，并延迟到 pH 值升高被阻止的时间。微管介导的事件发生在细胞内 pH 值升高的卵中，甚至在 pH 值被人为升高的未受精卵中也是如此。这些结果表明，卵子微管的形成和正常功能是由受精过程中发生的细胞内 pH 值的变化直接或间接启动的。
The regulation of the microtubule-mediated motions within eggs during fertilization was investigated in relation to the shift in intracellular pH (pHi) that occurs during the ionic sequence of egg activation in the sea urchins Lytechinus variegatus and Arbacia punctulata. Microtubule assembly during formation of the sperm aster and mitotic apparatus was detected by anti-tubulin immunofluorescence microscopy, and the microtubule-mediated migrations of the sperm and egg nuclei were studied with time-lapse video differential interference contrast microscopy. Manipulations of intracellular pH were verified by fluorimetric analyses of cytoplasmic fluorescein incorporated as fluorescein diacetate. The ionic sequence of egg activation was manipulated i) to block the pHi shift at fertilization or reduce the pHi of fertilized eggs to unfertilized values, ii) to elevate artificially the pHi of unfertilized eggs to fertilized values, and iii) to elevate artificially or permit the normal pHi shift in fertilized eggs in which the pHi shift at fertilization was previously prevented. Fertilized eggs in which the pHi shift was suppressed did not assemble microtubules or undergo the normal microtubule-mediated motions. In fertilized eggs in which the pHi was reduced to unfertilized levels after the assembly of the sperm aster, no motions were detected. If the intracellular pH was later permitted to rise, normal motile events leading to division and development occurred, delayed by the time during which the pH elevation was blocked. Microtubule-mediated events occurred in eggs in which the intracellular pH was elevated, even in unfertilized eggs in which the pH was artificially increased. These results indicate that the formation and normal functioning of the egg microtubules is initiated, either directly or indirectly, by the shift in intracellular pH that occurs during fertilization.