Toxicogenomics: new strategies for ecotoxicology studies in autochthonous species II. The 'omic' era in non-model species. Transcriptome analysis for biomarker screening

Abstract

The emerging field of ecotoxicogenomics aims to combine large-scale approaches to study the responses of organisms to a toxicant. A holistic vision of gene and protein expression in response to toxic exposure contributes to the identification of cellular components, signalling pathways and novel mechanisms of action/response. Native species are preferential for evaluating the impact of contaminants generated by anthropic action. However, biomonitoring using autochthonous species (non-model organisms) is difficult owing to a deficiency of molecular biology data and analytical tools. Our experience in the study of biomarkers in the South American toad Rhinella arenarum revealed many difficulties of finding antibodies or designing probes for it. We performed a transcriptomic study in R. arenarum exposed to two organophosphorus pesticides. We determined that there are specific patterns of gene expression for each organophosphate tested. Thus, a transcriptome approach for biomarker screening seems to be helpful in defining specific gene expression behaviour for a given toxicant.