| Project/Area Number |
03404004
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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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 | The University of Tokyo |
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Principal Investigator |
MORISAWA Masaaki Univ.Tokyo., Sch.Sci.Prof., 理学部, 教授 (40013594)
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| Co-Investigator(Kenkyū-buntansha) |
OHTAKE Hideki Dokkyo Univ.Sch.Med.Assoc.prof., 医学部, 助教授 (00049214)
INABA Kazuo Univ.Tokyo, Sch.Sci.Assist.Prof., 理学部, 助手 (80221779)
AMEMIYA Shonan Univ.Tokyo, Sch.Sci.Assoc.Prof., 理学部, 助教授 (30011670)
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| Project Period (FY) |
1991 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥30,000,000 (Direct Cost: ¥30,000,000)
Fiscal Year 1994: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1992: ¥9,200,000 (Direct Cost: ¥9,200,000)
Fiscal Year 1991: ¥14,800,000 (Direct Cost: ¥14,800,000)
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| Keywords | Regulation of sperm motility / Fishes / Ascidians / Signal transduction / Second messenger / Monoclonal antibodies / Purification sperm attractant / cDNA cloning / 海水魚・淡水魚 / ニシン / ホヤ / 精子運動開始・活性化 / 精子走化性 / 遺伝子クローニング / トリプシンインヒビター / T型Ca^<2+>チャネル / 精子運動開始 / 精子運動活性化 / タンパク質リン酸化 / モノクローナル抗体 / 細胞内pH / 細胞内Ca^<2+> / 膜電位変化 / 精子運動能獲得 / 精子活性化 / サケ科魚類 / 海産魚類 / 細胞情報伝達機構 |
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| Research Abstract |
We found that during transit of sperm from the testis to the sperm duct of salmonid fishes, increases in external pH and HCO_3 cause increases in pH_i and cAMP which affect the motile apparatus of flagellum, axoneme, causing the acquisition of the potential for sperm motility. Concerning the initiation of sperm motility in salmonid fishes at spawning, we obtained the first finding that control of flagellar movement occurs at the limited portion i.e.basal part of flagellum using prepared monoclonal antibodies of the 15kDa motility initiating phosphoprotein (MIPP) with a molecular weight of 15KDa. In the freshwater cyprinid fishes and marine fishes, we showed the different sperm motility initiation mechanisms ; Decrease or increase in external osmolalities causes increase or decrease in K^+_i causing the initiation axonemal movement to confer motility to spermatozoa. In the activation of sperm motility, the substance released from herring egg which activate sperm motility were purified by using gel-filtration and isoelectric focusing chromatograpies and identified 5 proteins with MW of 8.1 KDa and with Pl of 4.9-5.4. cDNA of the HSAP with Pl 5.1 was cloned and amino acid sequence with 73 amino acid residues was defined. The HSAP is resemble to typsin inhibitors, suggesting that interaction between trypsin inhibitor-like HSAPs and trypsin-like receptor on the surface of spermatozoa causes the signal transduction mechanism which triggers the activation of herring sperm motility. The sperm activating and attracting factor (SAAF) released from the egg of Ciona was purified using several HPLC chromatographies and it was concluced that one molecule has two functions, sperm activation and sperm attraction. Further findings suggest that sperm activation requires both Ca^<2+> and cAMP,but sperm chemotaxis needs only Ca^<2+>, suggesting that one molecule triggers two different signal transduction systems.
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