Pollard E C, Achey P M
Biophys J. 1975 Nov;15(11):1141-54. doi: 10.1016/S0006-3495(75)85890-5.
The effect of prior treatment by inducing agents on the radioresistance of cells of Escherichia coli has been studied. In order to separate the induction process from the radiation-damage process, cells were first treated with inducing agents such as ultraviolet light, ionizing radiation, or nalidixic acid, allowed to become induced by incubation for 50 min and then given rifampin to prevent further induction. They were then tested for radiation sensitivity. It was found that all strains tested except recA-, lex-, and recB showed very apparent protection. Induction by UV had the most effect and by nalidixic acid the least. The time course of development of protection was observed in one case: it is 50% established in 15 min. The absence of effect in recA- and lex- is explainable by the fact that these cells cannot be induced, for example, for prophage or the inducible inhibitor of post-irradiation DNA degradation. We suggest that the inducible inhibitor of postirradiation DNA degradation is one factor in a recovery system possessed by E. coli cells.
已经研究了诱导剂预处理对大肠杆菌细胞辐射抗性的影响。为了将诱导过程与辐射损伤过程分开，首先用紫外线、电离辐射或萘啶酸等诱导剂处理细胞，通过孵育50分钟使其被诱导，然后给予利福平以防止进一步诱导。然后测试它们的辐射敏感性。发现除recA -、lex -和recB外，所有测试菌株都表现出非常明显的保护作用。紫外线诱导的效果最明显，萘啶酸诱导的效果最小。在一个案例中观察到了保护作用发展的时间进程：在15分钟内达到50%。recA -和lex -中没有效果可以用这些细胞不能被诱导来解释，例如，对于原噬菌体或辐射后DNA降解的诱导性抑制剂。我们认为辐射后DNA降解的诱导性抑制剂是大肠杆菌细胞所拥有的恢复系统中的一个因素。
