Establishment of a biosystem for quantification of the radiation effects with the medaka thymus.

2015 Fiscal Year Final Research Report

• Project/Area Number: 25340043
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Risk sciences of radiation and chemicals
• Research Institution: National Institute of Radiological Sciences
• Principal Investigator: Maruyama Kouichi 国立研究開発法人放射線医学総合研究所, 福島復興支援本部, 主任研究員 (70349033)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 小核試験 / メダカ / 放射線

Outline of Final Research Achievements

The purpose of this study is to establish a biosystem for the quantification of the detrimental effects from radiation at organ and chromosomal levels in the thymus of medaka fish.
In the present work, we have successfully established a biosystem. By using this system, the threshold dose from continuous gamma-irradiation was verified, at which significant atrophy of the thymus and marked increase in the frequency of the micronucleated cells were induced. So far, it was estimated that the threshold was at 10-50mGy/h for the thymus atrophy, and 1-10mGy/h for the increase of the micronucleated cells in medaka that had been exposed to gamma-irradiation for 2 weeks. These dose rates are much higher (more than 10 times) in comparison with the highest air dose rate (100uSv/h) in the 'difficult-to-return zones' near the crippled Fukushima nuclear plant designated by the government measured just after the accident.

Free Research Field

放射線生物学