Cell cycle dependence for the induction of 6-thioguanine-resistant mutations: G2/M stage is distinctively sensitive to 252Cf neutrons but not to 60Co gamma-rays.
Cell cycle dependence for the induction of 6-thioguanine-resistant mutation was investigated using synchronized mouse L5178Y cells after exposure to 4 Gy to 60Co gamma-rays or 1 Gy of 252Cf radiation (fission neutrons). Maximal mutation frequency was observed immediately after release from colcemid block (G2/M phase) after 252Cf radiation, whereas it was 1 h after the release (G1 phase) after 60Co gamma-rays. When the mutation frequency was plotted against the surviving fraction, a general correlation was observed between the two parameters except for G2/M and G1 phases which were more mutable per lethal event for 252Cf and 60Co radiations, respectively.
Tauchi
H
H
Department of Radiobiology, Radiation Effects Research Foundation, Hiroshima, Japan.
Nakamura
N
N
Sawada
S
S
D000818:Animals; D002142:Californium; D002453:Cell Cycle / Q000502:physiology*; D002460:Cell Line; D003037:Cobalt Radioisotopes; D004351:Drug Resistance; D016195:G2 Phase / Q000502:physiology; D005720:Gamma Rays; D051379:Mice; D008938:Mitosis / Q000502:physiology; D009154:Mutation; D009502:Neutrons; D013866:Thioguanine / Q000494:pharmacology
D003037:Cobalt Radioisotopes; D002142:Californium; D013866:Thioguanine