Cell inactivation, mutation and DNA strand-break induction by gamma-rays at very low temperatures.
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.
Kozubek
S
S
Institute of Biophysics, AS CR, Brno, Czech Republic.
Rýznar
L
L
Vítová
H
H
Mlejnek
P
P
Slotová
J
J
D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D005720:Gamma Rays; D017665:Hydroxyl Radical; D009154:Mutation; D013696:Temperature
D017665:Hydroxyl Radical; D004247:DNA