Quillardet P, Huisman O, D'Ari R, Hofnung M
Biochimie. 1982 Aug-Sep;64(8-9):797-801. doi: 10.1016/s0300-9084(82)80131-4.
We used a gene fusion, placing the lacZ gene encoding beta-galactosidase under the control of the sfiA promoter, to construct a new tester strain for genotoxic agents. The assay is performed in a few hours and involves simple enzymatic assays. The dose response curves contain a linear portion which enables to define the SOS Inducing Potency (SOSIP) of compounds. For the compounds tested SOSIPs extend over 7 decades and correlate generally well with the mutagenic potency assayed in the Salmonella/microsome assay (Mutatest) and in a phage induction assay (Inductest). Sensitivities (lowest amount detected) are comparable in the SOS Chromotest and Mutatest but lower in the Inductest. Our results suggest that at least part of the response in the Mutatest depends on the induction of an SOS function, and that most of the genotoxins are inducer of the SOS system -i.e. can lead to activation of the RecA protease.
我们使用了一种基因融合技术，即将编码β-半乳糖苷酶的lacZ基因置于sfiA启动子的控制之下，构建了一种用于检测基因毒性剂的新型测试菌株。该检测在数小时内即可完成，且涉及简单的酶促检测。剂量反应曲线包含一个线性部分，据此能够确定化合物的SOS诱导潜能（SOSIP）。对于所测试的化合物，SOSIP范围跨越7个数量级，并且通常与沙门氏菌/微粒体检测（Mutatest）和噬菌体诱导检测（Inductest）中测定的致突变潜能具有良好的相关性。SOS色变检测和Mutatest中的灵敏度（最低检测量）相当，但Inductest中的灵敏度较低。我们的结果表明，Mutatest中的至少部分反应取决于SOS功能的诱导，并且大多数基因毒素是SOS系统的诱导剂——即能够导致RecA蛋白酶的激活。
