Temporal sequence and spatial distribution of early events of fertilization in single sea urchin eggs.
Temporal sequence and spatial distribution of early events of fertilization in single sea urchin eggs.
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DOI：
10.1083/jcb.99.5.1647
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发表时间：
1984-11
影响因子：
7.8
通讯作者：
Reynolds, G T
中科院分区：
文献类型：
--
作者：
Eisen, A;Kiehart, D P;Wieland, S J;Reynolds, G T
对单个海胆卵的五个早期受精事件进行了测量和观察，揭示了这些事件的准确的时间序列和空间分布。在斑点沙蚕卵中，表面收缩波与膜去极化波一致(t=0)。这两个最早的事件紧随其后的是细胞质内游离钙的快速、扩张性增加，大约在23 S，由钙-水通道蛋白发光测量。膜退偏后，发光在40 S时达到峰值。在经过几分钟的衰变之前，发光会在一段时间内保持均匀的增强。在约51 S时，膜去极化后，吡啶核苷酸(NAD(P)H)荧光开始增强。受精膜在NAD(P)H荧光增强的同时，以波浪状的方式开始上升。在斑点石龙卵中也观察到了类似的结果。结果表明，虽然胞浆内游离钙的增加可能是卵子发生许多变化的重要原因，但胞浆内游离钙的升高并不直接导致皮质颗粒胞吐的传播波。
Measurements and observations of five early events of fertilization, singly and in pairs, from single sea urchin eggs have revealed the precise temporal sequence and spatial distribution of these events. In the Arbacia punctulata egg, a wave of surface contraction occurs coincident with membrane depolarization (t = 0). These two earliest events are followed by the onset of a rapid, propagated increase in cytoplasmic-free calcium at approximately 23 s as measured by calcium- aequorin luminescence. The luminescence reaches its peak value by 40 s after the membrane depolarization. The luminescence remains uniformly elevated for some time before its decay over several minutes. The onset of an increase in the pyridine nucleotide (NAD(P)H) fluorescence follows the membrane depolarization at approximately 51 s. The fertilization membrane begins its elevation in a wave-like fashion coincidentally with the increase in NAD(P)H fluorescence. Similar results are observed in the Lytechinus variegatus egg. The results suggest that while the increase in cytoplasmic-free calcium may be important for many changes occurring in the egg, the elevated-free calcium is not directly responsible for the propagated wave of cortical granule exocytosis.