| Project/Area Number |
11680553
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
環境影響評価(含放射線生物学)
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| Research Institution | Nagasaki University |
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Principal Investigator |
YOSHIKAWA Isao Nagasaki Univ.Faculty of Environmental Studies, Professor, 環境科学部, 教授 (80039528)
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| Co-Investigator(Kenkyū-buntansha) |
TAKATSUJI Toshihiro Nagasaki Univ.Faculty of Environmental Studies, Associate Professor, 環境科学部, 助教授 (70163219)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | LET / RBE / Heavy ion / Neutron / Somatic mutation / Drosophila |
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| Research Abstract |
To obtain information on the mutagenic potential of high-LET radiation, we analyzed the production of somatic mutations caused by ^<252>Cf fission neutrons and heavy particle ions accelerated with a synchrotron in terms of the RBE and LET of radiation sources. For this purpose, a Drosophila strain was constructed that enabled us to detect the two types of mutations simultaneously in the same fly. The detection of both wing-hair and eye-color mosaic spot mutations in the same fly allowed us to compare the frequencies of induced mutational events directly, without the ambiguity of separate experiments.
Larvae were irradiated at the age of 3 days post oviposition with ^<252>Cf fission neutrons, carbon beam or neon beam. In the neutron irradiation, the RBE values for wing-hair mutations were larger than that for eye-color mutation with about 8.2 times. The RBE of carbon ions for producing the wing-hair mutations increased with increase in LET.The estimated RBE values were found to be in the range 2 to 6.5 for the wing-hair. In neon beam irradiation, the RBE values for wing-hair mutations peak near 150 keV/μm and decrease with farther increase in LET.
On the other hand, the RBE values for the induction of the eye-color mutation are nearly unity in ^<252>Cf-neutrons and both ions through the LET range irradiated. We obtained the relationships between the initial DNA damage and LET in considering the mechanism of somatic mutation induction.
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