2001 Fiscal Year Final Research Report Summary
GENERATINGAND REGULATORY MECHANISMS OF DAILY RHYTHMS IN FISH
| Project/Area Number |
10460083
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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 |
General fisheries
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
AIDA Katsumi THE UNIVERSITY OF TOKYO, GRADUATE SCHOOL OF AGRICULTURAL AND LIFE SCIENCES, PROFESSOR, 大学院・農学生命科学研究科, 教授 (50012034)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Melatonin / Daily rhythm / Pineal organ / Retina / AANAT / Ayu / Rainbow trout / Circadian rhythm |
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| Research Abstract |
1. Identification of novel input pathway of photic information :
To clarify the molecular bases of novel input pathway of photic information except the retina, we decided full cDNA sequence of rhodopsin expressed in the ayu brain, which was thought to include photoreceptive unit in this fish. The cDNA sequence of the rhodopsin in the deep brain was consistent with that of the rhodopsin in the retina. In addition, from the photoreceptive pineal organ of ayu, we cloned exo-rhodopsin cDNA. Thus, the ayu brain has two different rhodopsins.
2. Molecular analysis of circadian clock system :
Melatonin is known to be a transmitter of environmental light-dark cycle and time information. To elucidate molecular mechanisms of melatonin synthesis in fish, we identified two cDNA clones of arylalkylamine N-acetyltransferase genes, AANAT1 and AANAT2 the limiting enzyme of melatonin synthesis, in the retina and pineal organ of ayu. Using reverse transcription-PCP (RT-PCR). We revealed that AANAT1 expressed in the retina but not in the pineal, while AANAT2 expressed in the pineal but not in the retina. We quantified AANAT1 mRNA accumulation in the retina and AANAT2 mRNA accumulation in the pineal and analyzed their 24 hours variations under various lighting condition by using real time detection PCR system, and revealed that both AANAT1 and AANAT2 mRNA accumulation were regulated by circadian clock.
3. Molecular analysis of melatonin receptor :
Though we tried CDNA cloning of melatonin receptor in the ayu brain by using RT-PCR with degenerated primers, we have not yet obtained its homologous cDNA.
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Research Products
(12 results)
