MP7 Toxicogenomics in Environmental Studies
Monday, 14 November 2005: 8:00 AM - 5:30 PM in Exhibit Hall

(BAI-1117-055321) Alterations in gene expression after exposure of mummichogs (Fundulus heteroclitus) to arsenic.

Bain, L¹, Gonzalez, H¹, ¹ University of Texas at El Paso, El Paso, TX, USA

ABSTRACT- Although arsenic has been detected as a contaminant in water bodies around the world, little is known about its mode of action on both adults and their exposed offspring. We examined changes in the morphology and gene expression in juvenile mummichogs (Fundulus heteroclitus) whose parents were exposed to 172ppb, 230ppb, or 575ppb arsenic for 10 days immediately prior to spawning. Total RNA from 6-week old hatchlings reared in clean water, as well as total RNA from the livers of the exposed adults, was used to examine differential gene expression using a 524-spot cDNA array. In general, the arrays showed an increase in the total number of differentially expressed genes as the concentration increased. Thus, as the concentration was lowered, the fish looked more like control fish with respect to their gene expression profile. There were a number of genes that changed in a dose-responsive manner, including cytochrome c oxidase subunit III, deiodinase, cathepsin C, and a lysozyme precursor, while other genes such as TBT-binding protein, cathepsin C, several ESTs, and MDR were changed in multiple exposure groups. Ultimately, we hope to use these markers to help predict physiological impacts due to arsenic exposure.

Key words: Fundulus heteroclitus, microarray, arsenic, mummichog