Gene expression data from yeast exposure to alachlor

The world-wide used herbicide alachlor is among the priority substances listed in the European Water Framework Directive. We aimed at finding molecular biomarkers in the model yeast Saccharomyces cerevisiae that may be used to predict potential cytotoxic effects of this xenobiotic while providing mechanistic clues possibly relevant for experimentally less accessible non-target eukaryotes. We used microarrays to carry out a gene expression profiling analysis in S. cereviseae strain BY4741 upon 2 hours exposure to alachlor at concentrations exerting slight to moderate levels of phenotypic effects (inhibition of yeast growth rate). Two exposure scenarios were analysed, namely the lowest observed effect concentration (LOEC; ~8% growth inhibition) and the 20%-inhibitory concentration (IC20), compared to control cells not exposed to the herbicide (CT02). Exponential standardized cell suspensions of S. cerevisiae BY4741 in minimal growth medium were incubated in the presence of 110 or 200 mg/L of ALA (corresponding to the LOEC and the IC20, respectively, of alachlor) or in medium non-supplemented with the herbicide (control cells, CT02) during 2 h, and used for total RNA isolation and hybridization on Affymetrix microarrays. Exposure experiments with each concentration of alachlor versus controls were carried out independently. For each exposure condition, independent biological triplicates were processed and analysed.