Utilizing Molecular Technologies for Bioindicator Research

Abstract

Endocrine acting compounds dispersed into the environment have been reported to adversely affect growth and reproduction of wildlife. Some of the compounds are industrial by-products, but evidence points to sewage treatment plants as a major source of these contaminants. Typically whole life studies with vertebrates and invertebrates are performed to determine adverse health effects. This approach is ecologically sound, but may not point to the mechanisms by which the contaminants exert their effects. Molecular technologies have the potential to shorten the time of evaluation and provide integrated information to tie changes at the molecular level with adverse health effects. We describe molecular approaches that can be used to determine changes in gene expression patterns elicited by exposure to contaminants. Differential display RT-PCR and microarray analysis are powerful methods to measure the biological effects of exposure to environmental compounds. Both techniques need to be validated by quantitative measurements such as real time quantitative PCR (Q-PCR). These assays are complementary to standard methods of assessing toxicant effects and should lead to quick assessment of molecular mechanisms of toxicity. Many laboratories have started to use molecular biomarkers for their studies and are making the case for their usefulness in risk assessment.

Development and validation of a 2,000‐gene microarray for the fathead minnow (Pimephales promelas)

“…We saw the need to develop this microarray because the fathead minnow has been a widely utilized species in ecotoxicology research and regulation in North America and elsewhere since the 1960s [17]. To date, only a small (200 gene) macroarray had been available for this species [18,19].…”