Comparison of Gene Expression Profile Data of Atrazine, Flusilazole and Tamoxifen in Budding Yeast Saccharomyces Cerevisiae

The measurements of global gene expression levels upon mposure to a chemical can be used to provide information about both the mechanism of action of toxicants and to form a sort of "genetic signature" for the identification of specific genetic markers of exposure and response. We have used DNA microarray analysis to measure gene expression changes after exposure to three cornpounds, the herbicide atradne, the fungicide flusilazole, and to the pharmaceutical compound tarnoxifen in the budding yeast Soucharomyces cerwtside. For every chemical we have tested three different concentrations, starting from very low and environrnentally- relevant concentrations. Some of the most interesting changes in gene regulation have theh been confirmed by Real Time PIX Gene expression profiling upon exposure to flusilazole showed reguIation in several genes involved in sterol and ergosterol metabolism. and lipid and fatty acid biosynthesis. A dear pattern of gene expression changes is apparent also at the lowest concentration tested of 1o - n~M (2ngiL). Atrazine exposure gives rise to a quite different gene expression pattern with only a limited number of expression changes in genes involved in DNA maintenance integrity and repair. These results suggest that it should be possible to use yeast DNA microarray to discriminate between these two classes of environmental pollutants using gene expression profiling. Preliminary data on tamoxifen will also be presented.JRC.DDG.H.5-Rural, water and ecosystem resource