| Project/Area Number |
12460094
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fisheries chemistry
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| Research Institution | School of Fisheries Sciences, Kitasato University |
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Principal Investigator |
KAMIYA Hisao School of Fisheries Sciences, Kitasato University, Professor, 水産学部, 教授 (80011964)
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| Co-Investigator(Kenkyū-buntansha) |
KOIKE Kazuhiko School of Fisheries Sciences, Kitasato University, Lecturer, 水産学部, 講師 (30265722)
JIMBO Mitsuru School of Fisheries Sciences, Kitasato University, Lecturer, 水産学部, 講師 (10291650)
SAKAI Ryuichi School of Fisheries Sciences, Kitasato University, Associate Professor, 水産学部, 助教授 (20265721)
MARUYAMA Tadashi Marine Biotechnology Institute Co. Ltd., Chief Investigator, 主任研究員
MURAMOTO Koji Graduate School of Agricultural Science, Tohoku University, Professor, 農学部, 教授 (90157800)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥9,400,000 (Direct Cost: ¥9,400,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2001: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2000: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | lectin / D-galactose-binding / octocoral / Sinularia / Symbiodinium / symbiosis / 八放サンゴ |
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| Research Abstract |
The cDNA cloning of SLL-2, a D-galactose-binding lectin of the octocoral Sinularia lochmodes, has revealed that SLL-2 had a sequence homology to those of "discoidin" group lectins. It is observed that the difference of 2 kD in the molecular weight of SLL-2 was present between that calculated from the deduced amino acid sequence of SLL-2 (10, 751) and that observed in SDS-PAGE(15, 000) and TOF-MS (13, 194). No neutral sugar was observed. On the other hand, the spectroscopic analysis and also a treatment with tyrosinase suggested the presence of dopa in a lectin molecule. SLL-2 seems to have a melanin-like component in the C-terminal region.
SLL-2 binds to cell surface of Symbiodinium cell. In this research, we tested the effect of SLL-2 to various dinoflagellates. Additions of ecologically relevant concentrations to the cultures of actively swimming Symbiodinium sp. (Type C) decreased number of the motile cells dramatically, and Symbiodinium cells begun to transform into stationary coccoid form while cell division was not affected. Non-symbiotic dinoflagellates also responded to SLL-2. Gymnodinium catenatum and Prolocentrum micans resulted in cell death after inflation and burst of the cells within 24 hours. Thus, present results strongly suggest that the lectin-mediated chemical signal contributes to a stable symbiosis between S. lochomodes and Symbiodinium. This is the first evidence of chemical recognition and physiological modulation observed between symbiotic dinoflagellates and a coral.
The screening for the similar component in the ocotocorals using rabbit antibodies against SLL-2 revealed that SLL-2 seems to be specific to the genus Sinularia.
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