Light dependency of resistance to ionizing radiation in Euglena gracilis.
The resistance of Euglena gracilis strains Z (wild type) and SM-ZK (chloroplast-deficient mutant) to ionizing radiation was investigated. The colony forming ability of E. gracilis strain Z was higher than that of strain SM-ZK after 60Cogamma-irradiation. For both strains, the resistance of light-grown cells was higher than that of dark-grown cells, suggesting that the light conditions during culture contribute to the radiation resistance of E. gracilis. The comet assay showed that the ability of rejoining DNA double-strand breaks (dsb) was much higher in the light-grown cells. These results suggest that E. gracilis possesses a light-induced repair system to cope with DNA dsb.
Hayashi
Hirotaka
H
Research Institute for Advanced Science and Technology, Osaka Prefecture University, 1-1 Gakuencho, Sakai 599-8531, Japan.
Narumi
Issay
I
Wada
Seiichi
S
Kikuchi
Masahiro
M
Furuta
Masakazu
M
Uehara
Kaku
K
Watanabe
Hiroshi
H
D000818:Animals; D004249:DNA Damage / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005056:Euglena gracilis / Q000235:genetics / Q000528:radiation effects*; D005720:Gamma Rays; D008027:Light; D009154:Mutation