MP7 Toxicogenomics in Environmental Studies
Monday, 14 November 2005: 8:00 AM - 5:30 PM in Exhibit Hall
(LEE-1117-806460) Development of a Gene Expression Screening Assay Using Zebrafish Exposed to Model Estrogens.
Lee, D1, Hoffmann, J1, Brill, J1, Price, B1, Versteeg, D1, 1 The Procter and Gamble Co., Cincinnati, Ohio, USA
ABSTRACT- Many natural and man-made compounds have been shown to affect the endocrine status of fish, and a variety of approaches are being developed to assay for endocrine activity. To date, most approaches tend to be cumbersome, limited in scope or prohibitively expensive to carry out with the dozens and perhaps thousands of compounds that may need to be tested. Our goal is to develop a rapid screening assay for endocrine disrupting compounds using q-rt-PCR. Using model endocrine active compounds and the zebrafish Affymetrix GeneChip, our strategy is to identify a suite of differentially expressed genes. We report our studies with female, adult zebrafish (Danio rerio) exposed to 17 
-ethinylestradiol (EE2). A variety of genes were identified that were differentially regulated in a dose and time-dependent manner. Genes selected were involved in retinoic acid metabolism, steroid hormone/action, insulin metabolism and cell cycle. Exposure to a model weak estrogen, t-pentylphenol, will be used to validate the discrimination capabilities of the selected genes. This process will be completed for other modes of endocrine activity (e.g., androgenicity, antiestrogenicity, etc.) to develop a suite of genes diagnostic of a range of endocrine modes of action. A procedure for using the gene expression screening assay using the q-rt-PCR with compounds of unknown activity will be discussed. The ultimate goal is to employ this suite of genes with a zebrafish hepatocyte immortalized cell line to develop in vitro screens for multiple chemicals mechanisms.
Key words: Estrogen, Zebrafish, PCR, Genechip