• toxicology;
  • aquatic ecology;
  • environmental indicators;
  • DNA microarrays;
  • ecotoxicogenomics;
  • emerging contaminants

Abstract:  In recent years, new classes of aquatic pollutants have received attention from environmentalists, scientists, and regulators due to their introduction into the environment, unforeseen effects associated with the pollutants, or enhanced analytical techniques presently capable of detecting them. Many of these emerging contaminants are not well studied, making predictions regarding their toxicity to aquatic organisms or environmental fate difficult. Genomic technologies, including DNA microarrays, have been employed in many areas of biology to study disease states and the interaction of chemicals and nutrients with organisms. Here, we present the potential utility of DNA microarrays to address the challenges of emerging contaminants. DNA microarrays produce gene expression profiles creating an illustration of how a pollutant is acting within an exposed organism. Homology searches and online tools such as Gene Ontology can aid in the inferring a Mode of Toxicity, which may guide toxicity testing and risk characterization. Signature gene expression profiles offer the potential to uncover novel biomarkers of exposure and predict the presence of these contaminants in aquatic organisms. The No Observed Transcriptional Effect Level may play a role in determining if a predicted environmental concentration poses a risk to a sensitive species within an ecosystem. Additionally, DNA microarrays may add a complementary approach to Toxicity Identification Evaluations and help characterize causal agents in complex effluents.