Studies on cell signaling for regulating sperm chemotaxis

关于中国海鞘精子趋化与活化的研究1)采用核磁共振和质谱联用技术测定了源自海鞘卵的精子活化与吸引因子（SAAF）的分子结构。该因子是一种新型甾体：(3R,4R,7R,25S)-3,4,7,26-四羟基胆甾-3,26-二硫酸酯。合成了类固醇，并证明了纳摩尔浓度的类固醇可以激活和吸引海鞘精子。2)在精子趋化的细胞信号传导过程中，钙离子通道在精子趋化过程中起着关键作用。此外，数值研究表明，两种不同的策略导致了海鞘和虹吸管动物的精子趋化性。3)细胞内，海鞘精子的激活信号，证明钙/钙调素/钙调素激酶系统激活K^+通道，导致膜超极化导致cAMP升高，通过轴突蛋白磷酸化激活精子运动。4)在太平洋鲱鱼（Clupea pallasi）精子活化的研究中，明确了Na^+/Ca^<2+>反向交换器的参与。5)在鲑科鱼类精子运动起始的细胞信号传导中，对camp依赖性蛋白激酶催化亚基进行了表征。此外，已知对鞭毛运动起始不可或缺的15kDa蛋白被纯化，并被表征。精子顶体反应在文文鱼中首次被发现，gtp锚定蛋白参与顶体反应在贻贝Mytilus edulis中也首次被发现。

On the studies of sperm chemotaxis and activation in the ascidians Ciona 1) molecular structure of sperm-activating and -attracting factor (SAAF) originated from the eggs was determined using NMR and MS/MS methods. The factor is the novel steroid : (3R,4R,7R,25S)-3,4,7,26-tetrahydroxycholestane-3,26-disulfate. The steroid was synthesized and it was demonstrated that nanomolar concentration could activate and attract the ascidian sperm. 2) In the cell signaling for the sperm chemotaxis, it was demonstrated that stor-operated calcium channel plays key role for the phenomenon. Furthermore, a numerical studies showed that two different strategies cause sperm chemotaxis in the ascidians and siphonophores. 3) In the cell, signaling for the activation of ascidian sperm, It was demonstrated that calcium/calmodulin/calmoduline kinase system activates K^+ channel and resulting membrane hyperpolarization causes cAMP increase, resulting in the activation of sperm motility through phosphorylation of axonemal proteins. 4) On the studies of sperm activation in the Pacific hering Clupea pallasi, participation of reversed Na^+/Ca^<2+> exchanger was clarified. 5) On the cell signaling for the, initiation of sperm motility in the salmonid fish, cAMP-dependent protein kinase catalytic subunit was characterized. Furthermore, the 15kDa protein, which is known to be indispensable for the initiation of flagellar motility, was purified, and it's characterized. The acrosome reaction of spermatozoa was first found in amphioxus in the world, and participation of GTP-anchored protein in the acrosome reaction was also first found the mussel, Mytilus edulis.