Developing and Using Sheepshead Minnow Microarrays for Ecotoxicology

DESCRIPTION (provided by applicant): Microarrays are a powerful way to measure the impact of contaminants in the environment, and sheepshead minnows (Cyprinodon variegatus) are the most commonly used species in salt water environmental testing. In this proposal, we explain how we will develop and validate a large microarray (5,000+ genes) in sheepshead minnows. We will conduct a number of short and long term exposures on sheepshead minnows using several anthropogenic compounds (pyrene, copper, cadmium, and bisphenol A), then use the microarrays to measure the gene expression signatures for these compounds. This data, along with a variety of physiological endpoints, will be the basis for a relational database. We will analyze the data and decipher the patterns resulting from the various exposures to identify the unique fingerprints for each compound. Microarrays in sheepshead minnows will round out EcoArray's offering of microarrays for environmentally significant aquatic species. Measurement and analysis of environmental contaminants is very important to the EPA in its Superfund monitoring activities, and the sheepshead minnow is an important species that is routinely used for the monitoring of coastal superfund sites. In addition, diagnosis of ecotoxological effects at the gene level in sentinel species like sheepshead minnow offer the promise of future ability to tie ecotoxicology to human health, a goal of the National Center for Toxicogenomics. Experiments by our research group and others have shown that microarrays can be used to detect changes in gene expression caused by exposure to contaminants, and it is clear that contaminants have unique genetic signatures. Because many contaminants act at the gene level to induce or repress gene expression through both receptor-mediated and non-receptor mediated pathways, microarrays can help to elucidate signaling pathways that are affected. In general, microarrays offer a direct, effective way to provide detailed data about the biological effects of the environment on animals. In addition, analysis using microarrays is generally considerably less expensive than current testing methods. With the successful completion of this grant, we will incorporate the sheepshead minnow microarray and its database into our existing product line and sell it to the EPA, USGS, researchers in academia, as well as industrial concerns interested in compound screening and environmental monitoring/remediation. This project will result in a fully developed microarray for ecotoxicology testing in salt water. This microarray, together with the database this project will begin, can provide detailed, gene-level data on the biological impact of a chemical or an environment. In so doing, it can lead to assessment not only of water quality, but also of the implications of chemicals and environments for human health.