Analysis of gene expression as a new tool in ecotoxicology and environmental monitoring

Abstract

Pollution affects biological mechanisms in exposed biota, with adverse effects on tissue, organism and, eventually, entire ecosystem levels. Ecotoxicological biomarkers reflect these pollutant-induced physiological alterations, usually by measuring changes in the activity of specific enzymes, or alterations in hormone or protein levels. New, robust polymerase-chain-reaction (PCR)-based methodologies for quantifying specific messenger-RNA molecules have allowed the development of a new family of biomarkers based on analysis of gene-expression patterns. These gene-expression biomarkers have already been applied to many aspects of risk assessment, from toxicological analyses of new substances to in-field monitoring schemes. We review the fundamentals of these techniques, their application in different environmental surveys, their limitations and the outlook for their use in the future.