REPETITIVE CALCIUM TRANSIENTS AND THE ROLE OF CALCIUM IN EXOCYTOSIS AND CELL-CYCLE ACTIVATION IN THE MOUSE EGG
REPETITIVE CALCIUM TRANSIENTS AND THE ROLE OF CALCIUM IN EXOCYTOSIS AND CELL-CYCLE ACTIVATION IN THE MOUSE EGG
复制标题
DOI：
10.1016/0012-1606(92)90265-i
复制
发表时间：
1992-01-01
影响因子：
2.7
通讯作者：
KLINE, JT
中科院分区：
文献类型：
--
作者：
KLINE, D;KLINE, JT
用钙螯合剂BAPTA（1，2-bis（o-aminophenoxy）ethane-N，N，N′，N′-tetraacetic acid）和荧光钙指示剂fluo-3在小鼠卵细胞中研究了钙在受精时皮质颗粒胞吐和细胞周期激活中的作用。将BAPTA和Fluo-3分别与0.01-50 μMBAPTA乙酰氧基甲酯（AM）和/或1-20 μ M Fluo-3 AM孵育30 min，然后进行体外受精。在所有情况下，将卵孵育在1.50 μMBAPTA AM中抑制皮质颗粒的胞吐作用。将钙螯合剂引入卵中，在1.0 μMBAPTA AM时阻断第二极体的形成。无论BAPTA AM浓度如何，所有卵子均发生精子进入。精子诱导钙的大幅度瞬时增加，持续2.3 ± 0.6 min，随后是持续0.5 ± 0.1 min的重复性瞬时增加，间隔为3.4 ± 1.4 min。用1.50 μMBAPTA AM孵育可抑制所有钙瞬变。引入BAPTA也抑制钙瞬变，胞吐，并恢复减数分裂后的钙离子载体A23187或SrCl 2，激活鸡蛋的应用程序。这些结果表明，受精时钙的增加是必需的皮质颗粒胞吐和恢复细胞周期在哺乳动物卵。
The role of calcium in cortical granule exocytosis and activation of the cell cycle at fertilization was examined in the mouse egg using the calcium chelator BAPTA (1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid) and the fluorescent calcium indicator fluo-3. BAPTA and fluo-3 were introduced into zona-free mouse eggs by a 30-min incubation with 0.01–50 μMBAPTA acetoxymethyl ester (AM) and/or 1–20 μMfluo-3 AM prior toin vitrofertilization. Incubation of eggs in ⩾5.0 μMBAPTA AM inhibited cortical granule exocytosis in all cases. Introduction of the calcium chelator into the egg blocked second polar body formation at ⩾1.0 μMBAPTA AM. Sperm entry occurred in all eggs regardless of the BAPTA AM concentration. Sperm induce a large transient increase in calcium lasting 2.3 ± 0.6 min, followed by repetitive transients lasting 0.5 ± 0.1 min and occurring at 3.4 ± 1.4-min intervals. Incubation with ⩾5.0 μMBAPTA AM inhibited all calcium transients. Introduction of BAPTA also inhibited calcium transients, exocytosis, and the resumption of meiosis following application of the calcium ionophore A23187 or SrCl2, which activate eggs. These results demonstrate that the calcium increase at fertilization is required for cortical granule exocytosis and resumption of the cell cycle in a mammalian egg.