PW05 Genomics and Proteomics
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW087) Effects of arsenic exposure on gene regulation in mummichogs.
Gonzalez, H1, Bain, L1, 1 University of Texas at El Paso, El Paso, TX, USA
ABSTRACT- Arsenic has been detected as a contaminant in drinking water supplies around the world. Experiments in animals and in cell cultures have shown that arsenic can increase oxidative damage to DNA, alter DNA methylation, increase protein-DNA cross links, induce apoptosis and alter the regulation of DNA-repair genes. In epidemiological studies arsenic has been found to increase the number of stillbirths and the number of prematurely born children, but little is known about its effects on the offspring. We are studying altered gene expression in the offspring of mummichogs (Fundulus heteroclitus), an estuarine fish species, whose parents were exposed to 0.4ppm arsenic for 10 days immediately prior to spawning. Total RNA was extracted from 1-month old hatchlings that were hatched and reared in clean water, and was used to construct a cDNA subtractive hybridization library. Using this library, we have found 24 genes whose expression was potentially altered by arsenic exposure. We have confirmed the differential expression of several of these genes by real-time PCR and have found that both myosin light chain 2 and type II keratin genes were significantly repressed in the hatchlings as a result of arsenic exposure. The results of the study will enhance our understanding about the regulation of genes as a result of arsenic exposure and the modes of action of this contaminant in aquatic environments.
Key words: Fundulus heteroclitus, arsenic, subtractive hybridization