Cadmium chloride-induced gene expression changes in D. melanogaster

Heavy metals and organic compounds, such as pesticides and plasticizers, exert toxicity through their ability to perturb molecular mechanisms. We investigated the ability of 18 compounds to modify the epigenetic state of the white locus in a Drosophila model of position-effect variegation (PEV). Our data indicate that cadmium chloride (CdCl2) is a potent enhancers of variegation. We demonstrate that genes differentially expressed upon CdCl2 exposure are enriched for genes that have heterochromatic states associated with them. Two genotypes (isogenic except for the Y chromosome) were either treated with CdCl2 or were raised on control food. Two-channel microarrays were used with balanced dye-swaps and the expression signal from each treatment/genotype combination was collected from four distinct slides.