Electrophysiological response to insemination in oocytes of Urechis caupo.
Electrophysiological response to insemination in oocytes of Urechis caupo.
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Urechis caupo 卵母细胞对授精的电生理反应。
DOI：
10.1016/s0012-1606(81)80011-5
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发表时间：
1981
影响因子：
2.7
通讯作者：
Gould-Somero,M
中科院分区：
文献类型：
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作者：
Holland,L;Gould-Somero,M
我们用光镜、电镜、电生理学和离子流测量等方法研究了尾刺蚓体腔卵母细胞对受精的反应。受精后，所有直径至少为20 - 120μm（最大值）的卵母细胞都能结合并接纳精子;这些卵母细胞都处于二倍体终变期，并作为单细胞悬浮在体腔液中，没有辅助细胞。所有大小的卵母细胞都比卵子更容易受到多精受精的影响，并且不能激活（完成减数分裂）;尽管如此，它们对授精的反应是在其一般形式和Na+依赖性方面与卵子的受精潜力相似的潜力的正向转变。然而，在卵母细胞中，电位正移的上升时间较长，并且电位没有达到正的幅度，显然至少部分是由于卵母细胞的K+电导更大。卵母细胞也不会形成永久性的多精受精阻滞，这种失败加上受精潜能的缓慢上升时间和降低的幅度与它们对多精受精的更大易感性相关。这些研究还证实，受精潜力，伴随着显着增加Na+和Ca 2+流入，是不足以启动发展，即使成熟的配子，所谓的鸡蛋，是在同一减数分裂（germinal vesicle）阶段的体腔卵母细胞。
We investigated the response to insemination of coelomic oocytes of the marine wormUrechis caupowith light and electron microscopy, electrophysiology, and by measuring ion fluxes. After insemination all oocytes from at least 20 to 120μm in diameter (the maximum) bind and admit sperm; these oocytes are all in diplotene-diakinesis and are suspended in the coelomic fluid as single cells with no accessory cells. Oocytes of all sizes are more susceptible to polyspermy than eggs and fail to activate (complete the meiotic divisions); nonetheless they respond to insemination with a positive shift in potential similar in its general form and Na+dependence to the egg's fertilization potential. However, in oocytes the rise time of the positive shift in potential is longer and the potential does not attain as positive an amplitude, apparently due, at least in part, to the oocytes' greater K+conductance. Oocytes also do not develop a permanent polyspermy block, and this failure plus the slower rise time and reduced amplitude of the fertilization potential correlates with their greater susceptibility to polyspermy. These studies also establish that a fertilization potential, accompanied by significant increases in Na+and Ca2+influx, is insufficient to initiate development even though the mature gamete, the so-called egg, is in the same meiotic (germinal vesicle) stage as the coelomic oocytes.