title: Gene biomarkers in diatom Thalassiosira pseudonana exposed to polycyclic aromatic hydrocarbons from contaminated marine surface sediments.
abstract: Marine diatoms have a key role in the global carbon fixation and therefore in the ecosystem. We used Thalassiosira pseudonana as a model organism to assess the effects of exposure to environmental pollutants at the gene expression level. Diatoms were exposed to polycyclic aromatic hydrocarbons mixture (PAH) from surface sediments collected at a highly PAH contaminated area of the Mediterranean Sea (Genoa, Italy), due to intense industrial and harbor activities. The gene expression data for exposure to the sediment-derived PAH mixture was compared with gene expression data for in vitro exposure to specific polycyclic aromatic hydrocarbons. The data shows that genes involved in stress response, silica uptake, and metabolism were regulated both upon exposure to the sediment-derived PAH mixture and to the single component. Complementary monitoring of silica in the diatom cultures provide further evidence of a reduced cellular uptake of silica as an end-point for benzo[a]pyrene exposure that could be linked with the reduced gene and protein expression of the silicon transporter protein. However some genes showed differences in regulation indicating that mixtures of structurally related chemical compounds can elicit a slightly different gene expression response compared to that of a single component. The paper provides indications on the specific pathways affected by PAH exposure and shows that selected genes (silicon transporter, and silaffin 3) involved in silica uptake and metabolism could be suitable molecular biomarkers of exposure to PAHs.
authors.affiliation: European Commission-Joint Research Centre, Institute for Environment and Sustainability, Ispra (VA), Italy.
authors.forename: Raquel N
authors.initials: RN
authors.lastname: Carvalho
authors.forename: Alina D
authors.initials: AD
authors.lastname: Burchardt
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Sena
authors.forename: Giulio
authors.initials: G
authors.lastname: Mariani
authors.forename: Anne
authors.initials: A
authors.lastname: Mueller
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Bopp
authors.forename: Gunther
authors.initials: G
authors.lastname: Umlauf
authors.forename: Teresa
authors.initials: T
authors.lastname: Lettieri
mesh_terms: D000595:Amino Acid Sequence; D001564:Benzo(a)pyrene / Q000633:toxicity; D015153:Blotting, Western; D017931:DNA Primers / Q000235:genetics; D017377:Diatoms / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D005786:Gene Expression Regulation / Q000187:drug effects*; D005819:Genetic Markers / Q000187:drug effects / Q000235:genetics; D019015:Geologic Sediments / Q000032:analysis*; D007558:Italy; D008522:Mediterranean Sea; D010455:Peptides / Q000235:genetics; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012822:Silicon Dioxide / Q000378:metabolism / Q000493:pharmacokinetics; D053719:Tandem Mass Spectrometry
chemical_list: D017931:DNA Primers; D005819:Genetic Markers; D010455:Peptides; D011084:Polycyclic Aromatic Hydrocarbons; D001564:Benzo(a)pyrene; D012822:Silicon Dioxide