Free calcium pulses following fertilization in the ascidian egg.
Free calcium pulses following fertilization in the ascidian egg.
复制标题
海鞘卵受精后游离钙脉冲。
DOI：
10.1016/0012-1606(89)90168-1
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发表时间：
1989
影响因子：
2.7
通讯作者：
Jaffe,LF
中科院分区：
文献类型：
--
作者：
Speksnijder,JE;Corson,DW;Sardet,C;Jaffe,LF
利用钙特异性化学发光光蛋白aequorin，我们测量了哺乳海鞘（sphallusia哺乳）和肠海鞘（ciona interinalis）单卵受精时游离胞质钙浓度的变化。在受精后不久，游离钙浓度在1分钟内从未受精卵的静止水平约90 μ min上升到峰值约7 μ min （phallusia）和10 μ min （ciona）。整个施肥过程持续时间为2-3分钟。紧随其后的是一系列12至25个较短的钙瞬态，峰值水平约为1-4 μM。这些受精后的脉冲在减数分裂完成时每隔1-3分钟出现一次，在第二极体形成时，它们在大约25分钟后停止。这种模式有一个有趣的例外，那就是在冬季的几个月里，在较低的温度下饲养的乔娜蛋。在没有外部钙的情况下进行人工授精，其脉冲模式与正常模式非常相似。根据这一结果，我们推断受精脉冲和减数分裂振荡所需的大部分（如果不是全部）钙是从内部源释放的。
Using the calcium-specific, chemiluminescent photoprotein aequorin, we have measured changes in the concentration of free cytosolic calcium at fertilization in single eggs of the ascidiansPhallusia mammillataandCiona intestinalis. Shortly after insemination, the free calcium concentration rises within a minute from a resting level of about 90 nMin the unfertilized egg to a peak level of about 7 μMinPhallusiaand about 10 μMinCiona. The total duration time of this fertilization transient is 2–3 min. It is immediately followed by a series of 12 to 25 briefer calcium transients with peak levels of about 1–4 μM. These postfertilization pulses occur at regular intervals of 1–3 min during the completion of meiosis, and they stop as soon as the second polar body is formed at about 25 min. An interesting exception to this pattern was observed in eggs fromCionathat had been raised at lower temperatures during the winter months. Insemination in the absence of external calcium inPhallusiaresults in a pulse pattern very similar to the normal pattern. From this result we infer that the bulk (if not all) of the calcium required for both the fertilization pulse and the meiotic oscillations is released from internal sources.