Transcriptomics responses in marine diatom Thalassiosira pseudonana exposed to the polycyclic aromatic hydrocarbon benzo[a]pyrene

• Published in: PloS one Vol. 6; no. 11; p. e26985
• Main Authors: Carvalho, Raquel N, Bopp, Stephanie K, Lettieri, Teresa
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.11.2011; Public Library of Science (PLoS)
• Subjects: Algae; Apoptosis; Aromatic hydrocarbons; Bacillariophyta; Base Sequence; Bax protein; Benzo(a)pyrene; Benzo(a)pyrene - toxicity; Benzopyrene; Biogeochemical cycles; Bioindicators; Biology; Biomarkers; Carbon; Carbon cycle; Cell cycle; Deoxyribonucleic acid; Diatoms; Diatoms - drug effects; Diatoms - genetics; DNA; DNA microarrays; DNA Primers; DNA probes; Ecosystems; Environmental changes; Environmental monitoring; Fatty acids; Gene expression; Gene sequencing; Genes; Genomes; Genomics; Heat; Heat shock; Heat shock factors; Heat shock proteins; Homeostasis; Lipid metabolism; Marine ecosystems; Marine environment; Metabolism; Mode of action; Nucleotide sequence; Oligonucleotide Array Sequence Analysis; Photosynthesis; Physiological aspects; Pollutants; Polycyclic aromatic hydrocarbons; Pyrene; Quality assessment; Quality control; Real-Time Polymerase Chain Reaction; Signal transduction; Silicon; Studies; Sustainability; Thalassiosira pseudonana; Toxicity; Transcriptome; Transporter; Water Pollutants, Chemical - toxicity; Water quality; Water quality assessments
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0026985

Diatoms are unicellular, photosynthetic, eukaryotic algae with a ubiquitous distribution in water environments and they play an important role in the carbon cycle. Molecular or morphological changes in these species under ecological stress conditions are expected to serve as early indicators of toxicity and can point to a global impact on the entire ecosystem. Thalassiosira pseudonana, a marine diatom and the first with a fully sequenced genome has been selected as an aquatic model organism for ecotoxicological studies using molecular tools. A customized DNA microarray containing probes for the available gene sequences has been developed and tested to analyze the effects of a common pollutant, benzo(a)pyrene (BaP), at a sub-lethal concentration. This approach in diatoms has helped to elucidate pathway/metabolic processes involved in the mode of action of this pollutant, including lipid metabolism, silicon metabolism and stress response. A dose-response of BaP on diatoms has been made and the effect of this compound on the expression of selected genes was assessed by quantitative real time-PCR. Up-regulation of the long-chain acyl-CoA synthetase and the anti-apoptotic transmembrane Bax inhibitor, as well as down-regulation of silicon transporter 1 and a heat shock factor was confirmed at lower concentrations of BaP, but not the heat-shock protein 20. The study has allowed the identification of molecular biomarkers to BaP to be later on integrated into environmental monitoring for water quality assessment.