2020年3月
Localization of sperm intracellular Ca2+ keeps fertilizability in the newt vas deferens.
Reproduction (Cambridge, England)
- ,
- ,
- ,
- 巻
- 159
- 号
- 3
- 開始ページ
- 339
- 終了ページ
- 349
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1530/REP-19-0252
Sperm intracellular Ca2+ is crucial for the induction of sperm-egg interaction, but little is known about the significance of Ca2+ maintenance prior to induction. In sperm of the newt Cynops pyrrhogaster, intracellular Ca2+ is localized to the midpiece during storage in the vas deferens, while extracellular Ca2+ is influxed in modified Steinberg's salt solution to promote a spontaneous acrosome reaction related to the decline of sperm quality. In the present study, sperm from the vas deferens were loaded with the Ca2+ indicator Fluo8H, and changes in Ca2+ localization in modified Steinberg's salt solution were examined. Calcium ions expanded from the cytoplasmic area of the midpiece to the entire tail in most sperm during a 1-h incubation and localized to the principal piece in some sperm within 24 h. Similar changes in Ca2+ localization were observed in reconstructed vas deferens solution that included ions and pH at equivalent levels to those in the vas deferens fluid. Sperm with Ca2+ localization in the entire tail or the principal piece weakened or lost responsiveness to sperm motility-initiating substances, which trigger sperm motility for fertilization, but responded to a trigger for acrosome reaction. The change in Ca2+ localization was delayed and transiently reversed by ethylene glycol tetraacetic acid or a mixture of Ca2+ channel blockers including Ni2+ and diltiazem. These results suggest that C. pyrrhogaster sperm localize intracellular Ca2+ to the midpiece through Ca2+ transport in the vas deferens to allow for responses to sperm motility-initiating substances.
- ID情報
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- DOI : 10.1530/REP-19-0252
- PubMed ID : 31940274