Caenorhabditis elegans as a Genomic Model for Toxicology

Effective toxicological testing of the vast number of new and existing chemicals currently in use will require efficient and cost effective methods. We evaluated the utility of a simple, low cost toxicity testing system employing the nematode Caenorhabditis elegans to identify toxicologically relevant changes in gene expression. Dichlorvos and fenamiphos, which are organophosphorous pesticides that inhibit acetylcholinesterase were chosen as model toxicants to test the usefulness of the C. elegans toxicity testing system, and mefloquine, which appears to perturb neuronal Ca++ homeostasis, provided an out-group for analysis. Keywords: gene expression array-based (RNA / in situ oligonucleotide) Concentrations of dichlorvos, fenamiphos, or mefloquine sufficient to prevent the development of 10%, 50%, or 90% of mid-vulval L4 worms to the early gravid adult stage at 24 h after exposure were determined in range finding experiments. For definitive experiments, mid-vulval L4 worms were exposed to one of the foregoing concentrations of dichlorvos, fenamiphos, or mefloquine for 8h. Exposures were performed in triplicate.