Selection and Morphological Alteration of dinoflagellates symbionts by chemical substances in marine invertebrates
Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants |
|Research Institution||School of Fisheries Sciences, Kitasato University |
KAMIYA Hisao Kitasato University, School of Fisheries Sciences, Professor, 水産学部, 教授 (80011964)
SAKAI Ryuichi Kitasato University, School of Fisheries Sciences, Associate Professor, 水産学部, 助教授 (20265721)
JIMBO Mitsuru Kitasato University, School of Fisheries Sciences, Lecturer, 水産学部, 講師 (10291650)
KOIKE Kazuhiko Kitasato University, School of Fisheries Sciences, Associate Professor, 水産学部, 助教授 (30265722)
MARUYAMA Tadashi Japan Agency for Marine-Earth Science and Technology, Director, 海洋生態環境研究部, 研究部長 (90373464)
|Project Period (FY)
2003 – 2005
Completed (Fiscal Year 2005)
|Budget Amount *help
¥13,100,000 (Direct Cost: ¥13,100,000)
Fiscal Year 2005: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2004: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥6,700,000 (Direct Cost: ¥6,700,000)
|Keywords||Sinularia lochmodes / Symbiodinium / Theonella sp. / Fungia echinata / Symbiosis / stony coral / octocoral / レクチン / シゲミタカトサカ|
The D-galactose-binding lectin, Sll-2, in the octocoral was effectively purified by affinithy chromatography on D-galactosamine-HiTrap column using Tris-HCl buffer containing 0.5% L-ascorbic acid and 0.1% kojic acid to avoid melanization and insolubilization of SLL-2 during purification. The purified SLL-2 gave many spot in 2D-PAGE with different pI values rangin from 3 to 5. However, after the N-glycopeptidase F treatment, the molecular weight of subunit (16.5kDa) reduced to 9.5kDa with three different pIs. These results suggested that SLL-2 is a mixture of isolectins composed of three glycosilated polypeptides, each equimolar of SLL-2a, b, and c.
In frontal affinithy chromatography, SLL-2 showed a high Ka value to Gal α1-3 (Fucα1-2) Gal β1-4 (Fucα1-3) Glc compared to that of Gal α1-3 (Fucα1-2) Gal β1-4 Glc. It also showed high affinity to Forssman antigen which contains GalNAc α1-3 GalNAc structure, and to certain kinds of carbohydrate having a Gal α1-3 Gal structure. These indicate t
hat SLL-2 binds to carbohydrate constituents derived from glycolipids but not to N-liked carbohydrates.
When the protein profiles of coccoid cells induced by the SLL-2 treatment was compared with that by untreated cells on 2-dimentional electrophoresis, the protein profile of SLL-2 treated CS-156 cells was much similar to that of spontaneous coccoid cells than to that of motile cells. Newly expressed proteins, named Bland B2, also confirmed to present in SLL-2-treated cells. B1 showed sequence homology to VDAC1.1 and outer mitochondrial membrane protein porin 1, and B2 to Merozoite surface protein 1 (fragment). In a confocal laser scanning microscopic analysis, we observed the alignment of F-actin and β-tubulin was different between a motile form and coccoid one. The change in the alignment and number of β-tubulin was correlated to the morphological transform from motile to coccoid in Symbiodinium.
The D-galactose-binding lectin (TDL) was purified from the hemolymph of a giant clam Tridaca derasa. TDL induced the transform from motile form to coccoid of Symbiodinium sp. However, the effect of TDL on Symbiodinium was species-specic. Interestingly, TDL stimulated the growth of Symbiodinium species tested. D-galactose-bindig lectin from various origins including plants and animals did not stimulate the transform or growth of Symbiodinium.
The stony coral Fungia echinata was also confirmed to possess a D-Galactose-binding lectin which alters the motile form to coccoid one to some extent. Some protein fractions were also observed to stimulate significantly the growth of Symbiodinium sp.
The factors which showed similar effects on Symbiodinium cells in the sponge Theonella sp. were determined to be depsipeptides, TPId and TP1436. These peptides altered the motile forms to coccoid ones and also depressed cell division completely. The effect was concentration-dependent, and TP-treated CS-156 cells recovered the regular diel alternation between motile and coccoid forms by washing. The similar effect on CS-156 cells was also recognized by the treatment with actin polymerization inhibitors such as Latrunculin A and also with protein kinase inhibitors such as Bisindolylmaleimide I. Present observation strongly suggests that SLL-2 affects the microfilament formulation in Symbiodinium cells and keep these cells in their coccoid stage. Less
Report (4 results)
Research Products (7 results)