Mechanism Regulating Ca2+-dependent Mechanosensory Behaviour in Sea Urchin Spermatozoa
Mechanism Regulating Ca2+-dependent Mechanosensory Behaviour in Sea Urchin Spermatozoa
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DOI：
10.1247/csf.10020
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发表时间：
2011-01-01
影响因子：
1.5
通讯作者：
Shingyoji, Chikako
中科院分区：
文献类型：
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作者：
Kambara, Yuka;Shiba, Kogiku;Shingyoji, Chikako
海胆精子的鞭毛运动受细胞内钙离子的调节。弗拉格列林是一种含有聚唾液酸的糖蛋白，以及其他膜蛋白，似乎对钙离子的控制起作用。为了阐明鞭毛运动背后的钙动力学机制，我们利用显微技术分析了精子的机械感觉行为反应。在含10 mM Ca~(2+)的海水中，精子呈环状游动。当用玻璃微针对精子头部施加机械刺激时，精子表现出一系列鞭毛反应，包括停止跳动(静止)和恢复直线游泳，然后再次沿圆形路径游泳，结果精子避开了障碍。用Fluo-4钙离子显像仪显示，静止期细胞内钙离子水平较高，之后逐渐下降。受体阻滞剂和抗候选成分抗体的作用表明，钙离子内流是由钙通道引起的，而钙外流是由鞭毛素相关的钙外流系统、质膜钙-三磷酸腺苷酶和K+依赖的钠/钙交换器引起的。结果表明，海胆精子依赖于钙离子的机械感觉行为受膜环境包括质膜蛋白和鞭毛素的有组织功能的调节。
Flagellar movement of the sea urchin sperm is regulated by intracellular Ca2+. Flagellasialin, a polysialic acid-containing glycoprotein, as well as other membrane proteins seems responsible for the Ca2+ control. To elucidate the mechanism of Ca2+ dynamics underlying flagellar movement, we analysed the sperm's mechanosensory behavioural responses by using microtechniques. In sea water containing 10 mM Ca2+, the sperm swim in circular paths. When a mechanical stimulus was applied to the sperm head with a glass microstylus, the sperm showed a series of flagellar responses, consisting of a stoppage of beating (quiescence) and a recovery of swimming in a straight path, followed by swimming in a circular path again; as the result the sperm avoided the obstacle. Ca2+-imaging with Fluo-4 showed that the intracellular Ca2+ was high in the quiescence and gradually decreased after that. The effects of blockers and antibodies against candidate components revealed that the Ca2+ influx was induced by Ca2+ channels and the Ca2+ efflux was induced by a flagellasialin-related Ca2+-efflux system, plasma membrane Ca2+-ATPases and the K+-dependent Na+/Ca2+ exchanger. The results show that the Ca2+-dependent mechanosensory behaviour of the sea urchin sperm is regulated by organized functioning of the membrane environment including the plasma membrane proteins and flagellasialin.