1988 Fiscal Year Final Research Report Summary
Mechanism of determination of the flagellar beat plane.
| Project/Area Number |
62480016
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物発生・生理学
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| Research Institution | University of Tokyo |
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Principal Investigator |
TAKAHASHI Keiichi Zoological Institute, Faculty of Science, University of Tokyo, 理学部, 教授 (40011481)
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| Co-Investigator(Kenkyū-buntansha) |
SHINGYOJI Chikako Zoological Institute, Faculty of Science, University of Tokyo, 理学部, 助手 (80125997)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Flagella / Sperm / Beat plane / Microtubule / Central micotubule / Dynein / 細胞運動 |
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| Research Abstract |
Eukaryotic flagellar movements are based on sliding between doublet microtubules in the axoneme. To induce a planar bend, the amount of sliding within the axoneme should be controlled so that the axoneme behaves as if it were composed of two groups of doublets. To study the mechanism of the formation of the planar bends, we applied a new experimental procedure to sea urchin sperm flagella. We have found that the beat plane of the flagella can be rotated over several cycles under an experimental condition in which the micropipette which held the sperm head with suction is vibrated and the plane of this imposed vibration is rotated. Spontaneous recovery of the beat plane occurs after the cessation of the vibration. As many as 11 cycles of revolution of the beat plane were followed by such spontaneous reverse rotations in live flagella.
The beat plane of conventional Triton models did not rotate for more than one revolution, but that of reactivated sperm that had been demembranated with a solution containing CHAPS and Nonidet P-40 rotated along with the plane of vibration for more than 10 revolutions. The response of the flagellum after a cessation of the vibration varied with the direction of rotation of the vibration plane: counterclockwise rotations were followed by a complete unwinding but clockwise rotations were followed by a partial unwinding. The initial velocity of unwinding was the same in both directions and was a function of the number of revolutions of the imposed winding. since the polystyrene beads attached to the axoneme did not rotate around the axoneme during the rotation, it is unlikely that the 9 doublets rotate around the axonemal axis. These results indicate that the flagellum can change the beat plane by changing the pattern of active sliding within the axoneme, possibly in association with rotation of the central tubules.
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