2003 Fiscal Year Final Research Report Summary
Molecular and endocrinological mechanisms of stress reaction in fishes
| Project/Area Number |
13306015
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Yuzuru 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 (40107412)
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| Project Period (FY) |
2001 – 2003
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| Keywords | stress / CRH / Arginine vasotosin / medaka / puffer fish / suppression of immune system / cortisol / suppression of reproduction |
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| Research Abstract |
Corticotropin-releasing hormone(CRH), arginine vasotosin(AVT), urotensin 1 and urocortin 2 & 3 genes were cloned from the brain of the Japanese eel, Anguilla japonica and medaka, Orizias latipes, and their structures were determined. Real-time quantitative PCR methods for CRH, urotensin 1, urocortin 2 & 3 and AVT have been established. CRH mRNA and somatic cortisol levels showed clear daily changes : high during daytime and low during night. Urotensin 1 mRNA and somatic cortisol levels were increased by short time exposure to stress (restraint and chasing) in the medaka. CRH receptor genes 1 & 2 were cloned from the brain of medaka, and their expressions were tissue specific.
It was indicated that rearing stress in a small tank inhibits gonadotropin-releasing hormone gene expression in the Japanese eel. In the medaka, repeated air-exposure suppressed gonadal maturation.
Cortisol, a stress hormone, suppressed IgM production in the cultured leucocytes collected from the blood, head kidney and spleen of rainbow trout. In the common carp, cortisol induced apoptosis of the cultured leucocytes, which resulted in the reduction of IgM production from the leucocytes. In the puffer fish, cortisol also induced apoptosis of the cultured leucocytes collected from the blood, head kidney and spleen. Furthermore, IgM mRNA levels in those cultured leucocytes were decreased by cortisol.
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Research Products
(10 results)
