@inproceedings{oai:jaxa.repo.nii.ac.jp:00013259,
 author = {小林, 一三 and 半田, 直史 and 河合, 幹彦 and 高橋, 規子 and 福田, 江里 and Kobayashi, Ichizo and Handa, Naofumi and Kawai, Mikihiko and Takahashi, Noriko and Fukuda, Eri},
 book = {宇宙利用シンポジウム, Space Utilization Research: Proceedings of Space Utilization Symposium},
 month = {Mar},
 note = {第25回宇宙利用シンポジウム(2009年1月14日-15日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The Twenty-fifth Space Utilization Symposium (January 14-15, 2009: ISAS/JAXA Sagamihara, Japan), It is necessary to develop a sensitive detection method of biological damage of cosmic radiation. Among radiation damages, DNA double-strand breakage is the most important because it leads to cell death, mutagenesis and carcinogenesis. We have been developing a very sensitive method for detection of DNA double-strand breakage. A bacterial (Escherichia coli) genome is made of a circular double-stranded DNA of 4,000,000 bp. This huge circle is easily trapped in the trees of agarose resin and cannot move in a electric field. However, a single double-strand break would make it a linear form, which can move through agarose under an alternating electric field. This represents an application of pulsed-field gel electrophoresis. Our goal is to establish this method for sensitive detection of DNA double-strand breakage in vivo. (1) We detected conditions for detection of chromosomal DNA double-strand breakage by pulsed-field gel electrophoresis. (2) We measured 'background' DNA double-strand breakage under a standard condition of bacterial growth. We used densitometry. We confirmed accumulation of broken chromosomes in a recBC mutant. (3) We measured DNA double-strand breakage after its artificial induction by methyl-specific endonuclease and UV irradiation. These results indicate that this represents a very sensitive method for detection of chromosomal double-stranded DNA breakage. We can try experiments in space to evaluate potential drawbacks of this method. In such cases, we need to find out further details, that includes appropriate physiological conditions for the bacterial cells and their containers. In order to increase sensitivity of this method, it is necessary to reduce the background chromosome breakage. We need to understand biology of chromosomal double-strand breakage, including programmed death in bacteria and damage repair., 形態: カラー図版あり, 資料番号: AA0064297015},
 publisher = {宇宙航空研究開発機構宇宙科学研究本部, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)},
 title = {ゲノムDNA二重鎖切断とその修復の高感度検出法の開発},
 volume = {25},
 year = {2009}
}