title: Low doses of gamma-radiation induce SOS response and increase mutation frequency in Escherichia coli and Salmonella typhimurium cells.
abstract: This study addresses use of two bacterial test systems (the Ames test and the SOS chromotest) to estimate the effects of low doses of γ-radiation. The most substantial increases in induction of SOS response and mutation frequencies were observed in the first 24h of exposure to γ-radiation as compared to the cells in the exposure-free control. Gamma-radiation also impaired growth and survival of S. typhimurium cells in the first 24h. The effects were attenuated at lower exposure doses and at longer exposure times. In the experiments conducted in this study, at 96h of exposure, the values of some of the γ-radiation effects were lower than the MID (minimum inducing dose) detection limits and, thus, were neglected. Long-term exposure to γ-radiation could also result in combined effects of γ-radiation and the death of cells in the culture.
authors.affiliation: Institute of Biophysics of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russia. Electronic address: radecol@ibp.ru.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bolsunovsky
authors.affiliation: FRC Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Frolova
authors.affiliation: Institute of Biophysics of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russia.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Dementyev
authors.affiliation: FRC Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia.
authors.forename: Olga
authors.initials: O
authors.lastname: Sinitsyna
keywords: Absorbed dose; Ames test; Dose rate; Mutation rate; SOS chromotest; γ-radiation