title: Cell inactivation, mutation and DNA strand-break induction by gamma-rays at very low temperatures.
abstract: Cell inactivation, mutation and DNA strand-break induction by gamma-radiation have been investigated at very low temperatures (-78 degrees C, -196 degrees C, and -268 degrees C). In Escherichia coli Ymel, lacI+-->lacI- and Salmonella typhimurium TA102, his--->his+ dose-modifying factors determined for low radiation doses are similar for both mutation induction and cell inactivation. The sensitivity of repair-deficient strains E. coli polA- and E. coli recA- was also reduced at low temperature to a comparable extent. This suggests that the lesions which are responsible for cell inactivation and mutagenesis could be strongly mutually related and/or that different types of lesions which are responsible for cell inactivation and mutation induction in bacteria are reduced at low temperature to the same or similar extent. Likewise, a lower yield of DNA strand breaks in plasmids irradiated at low temperature was observed.
authors.affiliation: Institute of Biophysics, AS CR, Brno, Czech Republic.
authors.forename: S
authors.initials: S
authors.lastname: Kozubek
authors.forename: L
authors.initials: L
authors.lastname: Rýznar
authors.forename: H
authors.initials: H
authors.lastname: Vítová
authors.forename: P
authors.initials: P
authors.lastname: Mlejnek
authors.forename: J
authors.initials: J
authors.lastname: Slotová
mesh_terms: D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D005720:Gamma Rays; D017665:Hydroxyl Radical; D009154:Mutation; D013696:Temperature
chemical_list: D017665:Hydroxyl Radical; D004247:DNA