Eisen A, Kiehart D P, Wieland S J, Reynolds G T
J Cell Biol. 1984 Nov;99(5):1647-54. doi: 10.1083/jcb.99.5.1647.
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.
对单个海胆卵受精的五个早期事件进行单独及成对的测量与观察，揭示了这些事件精确的时间顺序和空间分布。在刺冠海胆卵中，表面收缩波与膜去极化同时发生（t = 0）。这两个最早的事件之后，通过水母发光蛋白发光测量，在大约23秒时细胞质游离钙开始快速、传播性增加。膜去极化后40秒时发光达到峰值。发光在一段时间内保持均匀升高，然后在几分钟内衰减。吡啶核苷酸（NAD(P)H）荧光增加的起始在膜去极化后约51秒。受精膜与NAD(P)H荧光增加同时以波状方式开始升高。在多棘海胆卵中观察到类似结果。结果表明，虽然细胞质游离钙的增加可能对卵中发生的许多变化很重要，但游离钙升高并非直接导致皮质颗粒胞吐的传播波。
