Meeting Abstract

P3.24  Sunday, Jan. 6  Effects of the herbicide atrazine on gene expression in the zebrafish, Danio rerio: a microarray analysis BROWNE, D. E.*; LEWIS, K. R.; BAKER, D. M.; University of Mary Washington, Fredericksburg, VA; University of Mary Washington; University of Mary Washington dbaker2@umw.edu

Atrazine has been the most widely used conventional herbicide in the United States for many years, and consequently is one of the most common pollutants in American groundwater. Previous research has shown that atrazine exposure negatively affects growth and development, metabolism, and immune function in a variety of vertebrates. In order to identify the molecular pathways underlying these effects, we used whole-transcriptome microarray analysis to test for changes in gene expression in the brain of the zebrafish (Danio rerio ) after atrazine exposure. We exposed juvenile zebrafish to environmentally relevant levels of atrazine (400 ppb) for 15 days, beginning at 35 days post fertilization. RNA was isolated from whole heads immediately after exposure and at maturity (35 weeks) and cDNA levels from atrazine-treated fish were compared to those from control fish using a zebrafish 12x135K array. We identified 62 differentially regulated genes (p ≤0.05, fold change ≥2 or ≤0.5) in the juvenile fish and 57 differentially regulated genes in the adults, indicating that exposure to atrazine during development has both acute and long-term effects on gene expression. The affected genes encode peptides that function in development (regulators of cell growth, differentiation, proliferation, and apoptosis); intercellular signaling (receptors, ligands, and transducers); as well as transcription factors, membrane transporters, and metabolic enzymes.