Meeting Abstract
Many chemicals including pesticides, pharmaceuticals, surfactants, and plasticizers have been detected in surface waters. Several of these chemicals of emerging concern [CECs] have been shown to cause adverse outcomes in aquatic organisms. Although a large body of research exists documenting the effects of exposure to single chemicals in laboratory settings, aquatic organisms are exposed to complex mixtures of chemicals that vary in time and space. A better understanding of the biological consequences propagated by exposure to environmentally relevant, complex mixtures of CECs is needed for effective regulation and management of ecosystems. Transcription profiling provides information on a wide range of physiological processes that are potentially affected by exposure. To characterize effects caused by contaminant mixtures, we exposed cultured fathead minnows (Pimephales promelas) to water from 4 different rivers in flow-through mobile laboratories in the fall of 2014. The exposure locations were chosen to capture unique landuse types, including agricultural, urban, mixed-use, and forested, thus presenting with different contamination profiles. We will measure genome-wide transcript abundance using microarrays in the livers of males exposed for 6 days. A hypothesis-driven approach will be used to test for changes in a subset of genes known to be sensitive to CECs, e.g. hormone receptors, steroidogenic enzymes, and xenobiotic receptors. We will use a systems approach to identify differentially expressed genes across all 60,000 microarray features. The DEG lists will be analyzed for enrichment of genes associated with specific cellular pathways and biological processes using GSEA and SNEA.
