2013 Fiscal Year Final Research Report
Integrative studies on mechanically mutable connective tissue
| Project/Area Number |
21570075
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Animal physiology/Animal behavior
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
MOTOKAWA Tatsuo 東京工業大学, 生命理工学研究科, 教授 (80092352)
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| Project Period (FY) |
2009-04-01 – 2014-03-31
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| Keywords | 棘皮動物 / 結合組織 / 力学的性質 / ナマコ |
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| Research Abstract |
Mechanically mutable connective tissue (CCT) takes 3 different mechanical states, soft (S), standard (M), and stiff (H). We have isolated from sea cucumbers "NSF", a 2.4 kDa-protein, that caused M to H transition and "softenin", a 20 kDa-protein, that caused M-to-S transition. From these and the images of electron microscopy, we proposed the following molecular mechanism for stiffness changes: the transition from S to M is caused by the aggregation of collagen molecules induced by tensilin, which is antagonized by softenin; the transition from M to H is caused by cross bridging between collagen fibrils by NSF.
The oxygen consumption of 3 states of CCT from 3 different animal classes were measured and compared to that of muscles. The amount to oxygen consumption was lowest in M and highest in S that was far lower than that of relaxed muscles. The posture maintenance through CCT was shown to be the economical way that contributed the low metabolic rate of echinoderms.
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