2000 Fiscal Year Final Research Report Summary
Physiological and molecular genetical studies on the cell signaling for regulation of sperm motllity
Project/Area Number |
09440276
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Research Category |
Grant-in-Aid for Scientific Research (B).
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
動物生理・代謝
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Research Institution | The University of Tokyo |
Principal Investigator |
MORISAWA Masaaki The University of Tokyo, Graduate School of Science, Professor, 大学院・理学系研究科, 教授 (40013594)
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Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Manabu The University of Tokyo, Graduate School of Science, Assistant Professor, 大学院・理学系研究科, 助手 (60301785)
OKA Yoshitaka The University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (70143360)
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Project Period (FY) |
1997 – 2000
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Keywords | ascidians / herring fish / amphyoxus / humans / sperm activating factor / sperm chemotaxis / Ca2+ / Na+ exchange mechanism / high speed video analysis |
Research Abstract |
In the studies on the activation of sperm motility, it has been established that calcium ions is a prerequisite second messenger for the activation of herring sperm whose motility is activated by egg derived Herring Sperm Activating proteins(HSAPs), but cAMP is not necessary for the sperm activation. Furthermore, it was found that increase in the calcium ions is produced by the calcium/sodium exchange mechanism and plays a key role in the sperm activation. Occurrence of membrane depolarization concomitantly with the activation of sperm motility was also found. In the ascidians, Ciona intestinalis and C.savignyi The molecular structure of Sperm Activating and Attracting Factor(SAAF)was decided. It is the new steroid with 2 sulfuric acid residues. Quantitative studies on the sperm chemotaxis has been performed using computer analysis of the trajectory in a spermatozoon whose swimming direction exhibits chemotaxis toward an egg. In the present study, more detailed analysis was conducted us
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ing high speed video system to improve the quantitative analysis of sperm chemotaxis. Follicular fluid from human eggs contains factor(s)responsible for the activation of sperm motility and sperm chemotaxis. In the present study, we tried to isolate the factor for sperm activation using extraction of the factor by organic solvents, such as ethanol and chloroform. Further purification of the factor was performed by several chromatographical techniques, and we concluded that the purified factor will not be progesterone and atrial natriuretic factor that had been considered as factors responsible for sperm activation and chemotaxis. Furthermore, cell signaling for the sperm activation which is triggered by the follicular factor is now under investigation. It has been found in our laboratory that sperm activation factor is bound and present in the sperm, and it is released from the sperm at spawning in sea water and activate motility of the sperm. The curious factor, sperm derived sperm activator was isolated in the conditioning medium including sperm isolated from testes and tried to be purified by column chromatographies. Furthermore, cell signaling for the sperm activation which triggered by the sperm-derived factor is under investigation. Less
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Research Products
(16 results)
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[Publications] Krasznai, Z., Marian T., Izumi, H., Damjanovich, S., Balkay, L., Tron, L.and Morisawa, M.: "Membrane hyperpolarization removes inactivation of Ca2+ channels, leading to Ca2+ influx and subsequent initiation of sperm motility in the common carp."Proc.Natl.Acad.Sci.USA. 97. 2052-2057 (2000)
Description
「研究成果報告書概要(欧文)」より
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