MDPI AG Acta Medica Okayama 1422-0067 26 15 2025 Acquired Radioresistance Through Adaptive Evolution with Gamma Radiation as Selection Pressure: Increased Expression and Induction of Anti-Stress Genes 7275 EN Takeshi Saito Division of Radiation Life Science, Institute for Integrated Radiation and Nuclear Science, Kyoto University Hiroaki Terato Department of Radiation Research, Advanced Science Research Center, Okayama University Elucidating the mechanisms of radioresistance in highly radiotolerant organisms can provide valuable insights into the adaptation and evolution of organisms. However, research has been limited on many naturally occurring radioresistant organisms due to a lack of information regarding their genetic and biochemical characteristics and the difficulty of handling them experimentally. To address this, we conducted an experiment on adaptive evolution using gamma radiation as the selection pressure to generate evolved Escherichia coli with gamma radiation resistance approximately one order of magnitude greater than that of wild-type E. coli. Gene expressions in all wild-type and evolved radioresistant E. coli in the presence or absence of gamma irradiation were analyzed and compared using RNA sequencing. Under steady-state conditions, the genes involved in survival, cell recovery, DNA repair, and response following stress exposure were upregulated in evolved E. coli compared with those in wild-type E. coli. Furthermore, the evolved E. coli induced these genes more efficiently following gamma irradiation and greater DNA repair activity than that in the wild-type E. coli. Our results indicate that an increased steady-state expression of various anti-stress genes, including DNA repair-related genes, and their highly efficient induction under irradiation are responsible for the remarkable radioresistance of evolved E. coli. No potential conflict of interest relevant to this article was reported.

岡山大学大学院教育学研究科 Acta Medica Okayama 1883-2423 184 2023 高等学校芸術科音楽における創作分野の実践的研究― 旋律の構造に着目して ― 43 51 EN Takeshi SAITOH Faculty of Education, Okayama University Teruaki TOKUDA Okayama Sozan Senior High School 10.18926/bgeou/66133 　本研究は，高等学校芸術科音楽（以下，音楽Ⅰ）における創作学習を通して，創作に対する生徒の思考やその変化を捉えることを目的としている。創作の際は，音同士の細かな連結やその展開を示す「構造」という視点を基盤とし，間奏において表したいイメージと関わらせながら制作を進めた。生徒の作品からは，音程関係やリズムの繰り返し方に工夫を凝らした様子が見受けられ，微視的な構造と表現したいイメージとが強く結びついた作品が発表された。また，ワークシートやふりかえりフォームからは，困難な創作内容になるほど学習に興味をもっていたことがわかり，作曲の最も微視的視点である構造が，生徒の興味をもって深まっていたことが明らかとなった。 No potential conflict of interest relevant to this article was reported.