Promoters in multi cellular systems

The use of transgenic cells and organisms possessing a specific promoter make it possible to fine tune for the different types of stress caused by a chemical or sample. Unlike reporter genes, promoters are species-specific, requiring promoter isolation from the test organism. As a result, different promoters have been characterized for various test species. Some frequently used promoter systems will be described here. 

Prokaryotic promoters. Prokaryotic systems are generally used for rapid screening assays. A well established example is the Ames test that was developed with Salmonella in the 1970s (Ames, 1979 McDaniels et al., 1990 Reifferscheid and Heil, 1996) and is still considered as the standard mutagenicity assay. 

Orser developed the Pro-Tox assay to determine the fingerprint of a chemical compound based on 16 different stress promoters, proving the possible broad use of E. coli as a transgenic screening system (Orser et al., 1995). 

Eukaryotic systems. In eukaryotic cells and organisms, reporter genes similar to those used for prokaryotic cells can be utilized, although for some genes optimized, mutated versions have been developed. 

Two yeast stress promoters RAD54 and RNR2 were fused transcriptionally to GFP to screen for general stress (Afanassiev et al., 2000). Billinton et al. (1998) developed a codon-optimized GFP version for yeast. 

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