Construction and evaluation of a cea-lacZ gene fusion for the detection of environmental mutagens and carcinogens.
The cea-kil operon of the ColE1 plasmid is negatively regulated by the LexA-repressor and therefore, it is under the control of SOS regulation. We constructed a gene fusion between the cea and lacZ genes. Expression of the translational fusion can be easily detected by monitoring the levels of beta-galactosidase. Since the whole detection system is plasmid-based, it can be used in both Escherichia coli and Salmonella typhimurium strains. The SOS-function-inducing activities of 14 chemical mutagens were investigated in E. coli K12 and in two S. typhimurium Ames-strains and compared with results obtained by the SOS-chromotest and by the Umu-test. To correct for the inhibitory effects of test chemicals on mRNA and/or protein synthesis, the level of the constitutive chloramphenicol acetyl transferase was assayed in parallel.
Schumann
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W
Lehrstuhl für Genetik, Universität Bayreuth, F.R.G.
Songür
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N
Miltenburger
H G
HG
D001412:Bacillus subtilis / Q000235:genetics; D003086:Bacteriocin Plasmids; D002274:Carcinogens, Environmental; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003001:Cloning, Molecular; D003087:Colicins; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D008826:Microbial Sensitivity Tests; D009152:Mutagenicity Tests / Q000379:methods*; D009153:Mutagens; D011993:Recombinant Fusion Proteins / Q000235:genetics*; D013014:SOS Response, Genetics / Q000502:physiology; D012486:Salmonella typhimurium / Q000235:genetics*; D001616:beta-Galactosidase / Q000235:genetics
D002274:Carcinogens, Environmental; D003087:Colicins; D009153:Mutagens; D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase; D001616:beta-Galactosidase