Analysis of sperm-dependent electrical responses during amphibian fertilization.

两栖动物受精过程中精子依赖性电反应的分析。

• 批准号: 61540521
• 负责人: IWAO Yasuhiro
• 金额: $ 0.83万
• 依托单位: Faculty of Science, Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61540521/
• 关键词: Fertilization Potential; Polyspermy Block Mechanism; Cross-fertilization; 両生類; 受精; 精子; 多精防止

We investigated the changes of ionic permeabilities in egg plasma membrane during normal fertilization on anran (toad) and urodele (newt) amphibians with ionsubstitution, inhibitors of ionic channels, and voltage-clamping. In the fertilization of mature toad eggs, we observed the elicitaiton of a spike-like depolarization potential before the positive platea of fertilization potential that has been descrived previously. This spike-like potential is, like the platea, mediated by increased permeabilty to halides such as Cl^- or I^-. In addition, in the polyspemic fertilization of immature toad oocytes, the same spike-like potential was elicited in response to each sperm entranece. These spike potenial are depends on the penetration of sperm into the egg. On the other hand, there is no pronounced electrical changes during the fertilization of newt eggs, but the egg elicited small hyperpolarizing potentials that corresponded to each sperm entrance. It is not yet clear what ionic channels p … More articiapte to these hyperpolarization. According to this investigation, howerver, we have found that the eggs of amphibians elicit the electrical changes that depend on the sperm entrance.In the cross-fertilization between the toad eggs and the newt sperm, we were not able to find the spike-like potential, but the eggs elicited a gradually-changed hyperpolarization before the positive platea of fertilization potential, that was never observed in the normal fertilization. This hypserpolarization is mediated by mainly an increased permeability of monovalent cations such as Na^+. We were not able to find the condition that the toad sperm can fertilize the newt eggs, but we found that the salamander sperm were able to fertilize the newt eggs. The newt eggs elicited several smal hyperpolarization that corresponded well with each seprm entrance. Overall results indicate that both toad and newt eggs open very different ionic channels depending on the species of sperm that enter the eggs. The ionic channels that meiated these potential changes might be in the sperm plasma membrane and might be provided into the egg plasma membrane during membrane fusion at the fertilization. Less

采用离子替代法、离子通道抑制剂法和电压钳法，研究了两栖动物安然（蟾蜍）和有尾目（蝾螈）正常受精过程中卵质膜离子渗透性的变化。在蟾蜍成熟卵的受精过程中，我们观察到在受精电位的正板之前，有一个尖峰状的去极化电位被激发出来。与血小板一样，这种尖峰电位也是通过增加对卤素（如Cl^-或I^-）的渗透性来调节的。此外，在蟾蜍卵母细胞多精受精中，每次精子进入都能引起同样的尖峰电位。这些峰值电位取决于精子进入卵子的穿透力。另一方面，在蝾螈卵的受精过程中没有明显的电变化，但是卵引起了与每个精子入口相对应的小的超极化电位。目前尚不清楚什么离子通道可以促进 ...更多信息 articiapte这些hyperpolarization极化.然而，我们发现两栖动物的卵在受精过程中产生了依赖于精子进入的电变化，在蟾蜍卵与蝾螈精子的异卵受精过程中，我们没有观察到尖峰电位，但在受精电位的正板之前，卵产生了一个渐变的超极化，这在正常受精过程中是没有观察到的。这种超极化主要是由一价阳离子（如Na^+）的渗透性增加介导的。我们无法找到蟾蜍精子能使蝾螈卵受精的条件，但我们发现蝾螈精子能使蝾螈卵受精。蝾螈卵引起了几个小的超极化，对应于每个seprm入口。总体结果表明，蟾蜍和蝾螈卵打开非常不同的离子通道，这取决于进入卵的精子种类。这些潜在变化的离子通道可能位于精子质膜上，并可能在受精时膜融合过程中进入卵子质膜。少

项目成果

Yasuhiro Iwao: "The spike component of the fertilization potential in the toad, Bufo japonicus: changes during meiotic maturation and abscence during cross-fertilization." Developmental Biology. 123. 559-565 (1987)

Yasuhiro Iwao：“蟾蜍受精潜力的尖峰成分：减数分裂成熟过程中的变化和异体受精过程中的缺失。”

Hisashi Yamasaki: Journal of Experimental Zoology. 243. 331-338 (1987)

山崎恒：实验动物学杂志。

Hisashi Yamasaki: "Behavior fo "accessory" somatic and sperm nuclei introduced into physiologically polypsermic newt eggs." Journal of Experimental Zoology. 243. 331-338 (1987)

Hisashi Yamasaki：“将“附属”体细胞核和精子核引入生理性多精子蝾螈卵中的行为。”

Yasuhiro Iwao: Zoological Science. 3. 1035 (1986)

岩尾泰弘：动物学。

Yasuhiro Iwao: Developmental Biology. 123. 559-565 (1987)

岩尾泰宏：发育生物学。