However , organism can react to the stress actively and the mutagenesis is not a passive event . sos response is employed in dna damaging agents challenged e . co / i , to cope with abnormal conditions 当受到外源dna损伤因子的攻击时,大肠杆菌e . coil能启动sos反应以应对不良环境,提高对致损伤刺激的耐受能力,减少损伤的发生。
It has also been demonstrated that sos response dependent accumulation of mutation during replication of dna that has not been attacked by exogenous dna damaging factors can be seen in challenged cells , termed as sos untargeted mutation 而在出现sos反应的细胞中还观察到了在复制过程中的产生的、发生在没有外源损伤dna上的突变事件,被称为sos非定标性突变。
百科解释
SOS反应(SOS response)也称应急反应,由克罗地亚人 Miroslav Radman 在1975年发现和命名,是指染色体DNA受到严重损伤时细胞做出的应激反应。在这种情况下,多种基因被诱导表达,其中1个拷贝的UmuC和2个拷贝的被截短的UmuD主要组成DNA聚合酶Ⅴ,后者可在DNA模板有切口的区域催化DNA复制。