@inproceedings{oai:jaxa.repo.nii.ac.jp:00013832,
 author = {谷田貝, 文夫 and 本間, 正充 and Yatagai, Fumio and Honma, Masamitsu},
 book = {宇宙利用シンポジウム　第20回　平成15年度, Space Utilization Research: Proceedings of the Twentieth Space Utilization Symposium},
 month = {Mar},
 note = {For estimating the genetic effects of space radiation, an effort has been made to establish the methodology for detecting the influences of low-dose ionizing radiation at chromosome level. Human lymphoblastoid cell TK6-20C was irradiated with 10 cGy of X-rays or C-ions and mutation frequency (MF) at the heterozygous thymidine kinase (TK) locus was determined by judgment of TFT resistance. Although an increase in MF from 5.7 x 10(exp -6) to 6.9 x 10(exp -6) by X-ray irradiation was not statistically significant, C-ion exposure increased MF to 17.9 x 10(exp -6), about 3-fold induction over background level. This induction was due to the enhancement of TK mutants exhibiting hemizygous-type LOH (loss of heterozygosity). Surprisingly the radiation-specific LOH patterns were observed in more than half of these hemizygous-type LOH events. Such LOH mutants can be considered as a result of end-joining repair of DNA double-strand breaks (DSB). Recently the restriction enzyme site I-SceI was introduced into the thymidine kinase (tk) gene of human lymphoblastoid cell line TK6 and a system was established to investigate the fate of DSBs quantitatively and qualitatively at molecular level. In this proceeding, it is reported that the results of fate of site-directed DSB are well consistent with the above molecular analysis for LOH mutants obtained after low-dose ionizing radiation exposure. Here, also proposed is the analysis by introducing I-SceI site into the TK locus of the cells returned from International Space Station (ISS) and detecting whether the fate of DSBS can be modified by the stay in ISS. In other words, such long stay can be considered as priming effect in the adaptive response., 資料番号: AA0046917027},
 pages = {80--83},
 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/ISAS)},
 title = {低線量宇宙放射線による遺伝的影響の検出:染色体DNA上に部位特異的に2重鎖切断を導入する手法の利用},
 year = {2004}
}