Fundamental study on molecular mechanism underlying repair of heavy-ion induced DNA damage in the

Matsuo, Yoichiro*; Izumi, Yoshinobu*; Hase, Yoshihiro; Sakamoto, Ayako; Nozawa, Shigeki; Narumi, Issei; Shimizu, Kikuo*

We have been studying ion-beam induced mutations in the budding yeast as a model of eukaryote cell. Yeast cells were irradiated with 220 MeV carbon ions with 107 keV/m LET. The survival rates following irradiation were determined on the basis of colony-forming ability. and strains showed hyper sensitivity, while the and strains showed relatively lower sensitivity to the carbon ion irradiation. The expression of gene was up-regulated following carbon ion irradiation but not rays. This difference may result from the repair pathway that operates in mutant strains.