Source and sinks for the calcium released during fertilization of single sea urchin eggs.
Source and sinks for the calcium released during fertilization of single sea urchin eggs.
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DOI：
10.1083/jcb.100.5.1522
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发表时间：
1985-05
期刊：
影响因子：
--
通讯作者：
Reynolds GT
中科院分区：
文献类型：
--
作者：
Eisen A;Reynolds GT
在单卵海胆，Arbacia punctulata受精过程中释放的细胞内钙的源和汇进行了研究。单个卵被显微注射钙光蛋白，水母发光蛋白。用显微镜-光电倍增管测量钙-水母发光蛋白发光，或用显微镜-图像增强器-视频系统观察钙-水母发光蛋白发光。在正常的卵子中，观察到繁殖释放。钙的来源进行了调查，在细胞器分层离心鸡蛋和线粒体解偶联剂的使用。在细胞器分层的离心卵中，发现钙-水母发光蛋白的发光起源于透明区。透明区的主要成分是内质网。钙的其他潜在来源是线粒体。他们的钙瞬变的贡献进行了研究，通过暴露的水母发光蛋白注射的鸡蛋的线粒体解偶联剂之前或之后受精。受精前线粒体无钙释放。受精后线粒体释放出大量的钙。有趣的是，在解偶联剂的存在下受精的卵与未处理的卵相比，钙-水母发光蛋白发光没有增加。显然，在没有线粒体摄取的情况下，存在具有与线粒体相似的亲和力和能力的其他钙汇，但其性质尚不清楚。我们认为，内质网是受精后释放的细胞内钙的来源，线粒体是主要的汇。结果进行了讨论方面的代谢活化的鸡蛋。
The source and sinks for the intracellular calcium released during fertilization were examined in single eggs from the sea urchin, Arbacia punctulata. Single eggs were microinjected with the calcium photoprotein, aequorin. The calcium-aequorin luminescence was measured with a microscope-photomultiplier or observed with a microscope-image intensifier-video system. In the normal egg a propagated release has been observed. The source of the calcium was investigated in the organelle-stratified centrifuged egg and by the use of mitochondrial uncouplers. In the organelle-stratified centrifuged egg, the calcium- aequorin luminescence was found to originate from the clear zone. The principal constituent of the clear zone is the endoplasmic reticulum. Other potential sources of calcium are the mitochondria. Their contribution to the calcium transient was investigated by exposure of aequorin-injected eggs to mitochondrial uncouplers either before or after fertilization. There was no calcium released from the mitochondria before fertilization. A very large calcium store was released from the mitochondria after fertilization. Interestingly, eggs fertilized in the presence of uncouplers showed no increase in the calcium-aequorin luminescence over untreated eggs. Apparently, in the absence of mitochondrial uptake, other sinks for calcium with affinity and capacity similar to the mitochondria exist, but their nature is unknown. We suggest that the endoplasmic reticulum is the source of the intracellular calcium released upon fertilization and that the mitochondria are the principal sink. The results are discussed with regard to the metabolic activation of the egg.