Taddei F, Matic I, Radman M
Laboratoire de Mutagénèse, Institut Jacques Monod, Paris, France.
Proc Natl Acad Sci U S A. 1995 Dec 5;92(25):11736-40. doi: 10.1073/pnas.92.25.11736.
The inducible SOS system increases the survival of bacteria exposed to DNA-damaging agents by increasing the capacity of error-free and error-prone DNA repair systems. The inducible mutator effect is expected to contribute to the adaptation of bacterial populations to these adverse life conditions by increasing their genetic variability. The evolutionary impact of the SOS system would be even greater if it was also induced under conditions common in nature, such as in resting bacterial populations. The results presented here show that SOS induction and mutagenesis do occur in bacteria in aging colonies on agar plates. The observed SOS induction and mutagenesis are controlled by the LexA repressor and are RecA- and cAMP-dependent.
可诱导的SOS系统通过增强无差错和易出错的DNA修复系统的能力，提高了暴露于DNA损伤剂的细菌的存活率。可诱导的诱变效应预计通过增加细菌群体的遗传变异性，有助于其适应这些不利的生存条件。如果SOS系统在自然常见条件下（如静止的细菌群体中）也被诱导，那么它对进化的影响将更大。此处给出的结果表明，在琼脂平板上老化菌落中的细菌确实会发生SOS诱导和诱变。观察到的SOS诱导和诱变由LexA阻遏物控制，并且依赖于RecA和cAMP。
