1994 Fiscal Year Final Research Report Summary
Studies on the structural basis of flagellar motility-The organization of nexin links
| Project/Area Number |
05804053
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物生理・代謝
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| Research Institution | University of Tokyo |
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Principal Investigator |
SHIGYOJI Chikako University of Tokyo Graduate School of Science. Instructor, 大学院・理学系研究科, 助手 (80125997)
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| Co-Investigator(Kenkyū-buntansha) |
KAMIYA Ritsu University of Tokyo Graduate School of Science. Professor, 大学院・理学系研究科, 教授 (10124314)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Flagellar motility / Nexin links / Spermatozoa |
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| Research Abstract |
The flagellar bending is regulated by a mechanism different from that which generate active sliding. Interdoublet links (or nexin links) and radial spokes are strong candidates components of the regulatory system. The nexin links have been thought to resist sliding displacements of the doublet microtubules, but the organization and the function of the links are still not clear. In the present project, we examined the organization of the links in the flagella of Chlamydomonas and the sea urchin sperm by electron microscopy.
The fine structure of the axonemes of Chlamydomonas and the sea urchin sperm flagella was studied by electron microscopy. Both axonemes showed "9+2" structure, but in detail, there were some differences between the species. The nexin links appeared as a fine filamentous structure connecting adjacent doublets in KCl-extracted axonemes or in dialysed axonemes. The length of the link was about 34m, and always kept at an angle of about 35-50 degrees from the doublets. The links showed on elasticity or flexibility. The attachment site of the link to the A tubule and to the B tubule or the doublet was determined with regard to the distance from the spoke 2 along the doublet. The attachment site to the A tubule was constant, about 20 nm tipward from the spoke 2. However, the attachment site to the B tubule changed with the displacement between the adjacent doublets. This result suggests that the nexin links undergo cycles of attachment-detachment to the B tubule of the adjacent doublet.
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