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、离子通道阻滞剂和电压钳技术，研究了正常受精过程中两栖动物卵质膜离子通透性的变化。在成熟蛙卵受精过程中，我们观察到在前述受精电位的正平台之前，先有一个穗状去极化电位的激发。像平台一样，这种尖峰电位是通过增加对卤化物(如Cl^-或I^-)的渗透性来调节的。此外，在未成熟的蟾蜍卵母细胞的多点受精中，每一次精子进入都会诱发出相同的棘波电位。这些尖峰电位取决于精子进入卵子的情况。另一方面，蝾螈卵在受精过程中没有明显的电学变化，但卵子引发了与每个精子进入相对应的小超极化电位。目前还不清楚p…的离子通道是什么更倾向于这些超极化。然而，根据这项调查，我们发现两栖动物的卵引起了依赖于精子进入的电学变化。在蟾蜍卵与纽伦特精子的交叉受精中，我们没有发现尖峰电位，但在受精电位的正平台之前，卵引发了一种逐渐变化的超极化，这在正常受精中是没有观察到的。这种超极化主要是由单价阳离子如Na~+的渗透性增加所介导的。我们找不到蟾蜍精子可以使蝾螈卵受精的条件，但我们发现火蜥蜴精子能够使蝾螈卵受精。它们的卵引发了几个微小的超极化，与每个SEPRM入口处的情况很好地对应。总体而言，结果表明，根据进入卵子的精子种类的不同，蟾蜍卵和蝾螈卵打开的离子通道非常不同。反映这些电位变化的离子通道可能位于精子质膜中，并可能在受精时的膜融合过程中提供给卵细胞质膜。较少

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。