Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-35150 - Toxicogenomic Responses of Nanotoxicity in Daphnia magna Exposed to Silver Nitrate and Coated Silver Nanoparticles
Released on 4 August 2012, last updated on 13 August 2012
Applications for silver nanomaterials in consumer products are rapidly expanding, creating an urgent need for toxicological examination of the exposure potential and ecological effects of silver nanoparticles (AgNPs). The integration of genomic techniques into environmental toxicology has presented new avenues to develop exposure biomarkers and investigate the mode of toxicity of novel chemicals. In the present study we used a 15k oligonucleotide microarray for Daphnia magna, a freshwater crustacean and common indicator species for toxicity, to differentiate between particle specific and ionic silver toxicity and to develop exposure biomarkers for citrate-coated and PVP-coated AgNPs. Gene expression profiles revealed that AgNO3 and AgNPs have distinct expression profiles suggesting different modes of toxicity. However, the gene expression profiles of the different coated AgNPs were similar revealing similarities in the cellular effects of these two particles. Major biological processes disrupted by the AgNPs include protein metabolism and signal transduction. In contrast, AgNO3 caused a downregulation of developmental processes, particularly in sensory development. Metal responsive and DNA damage repair genes were induced by the PVP AgNPs, but not the other treatments. In addition, two specific biomarkers were developed for the environmental detection of PVP AgNPs; although further verification under different environmental conditions is needed. We exposed Daphnia magna to the 1/10 LC50 and LC25 of citrate coated and PVP-coated Ag nanoparticles and Ag+ as AgNO3 for 24-h. For each exposure condition, we performed 6 replicate exposures with 5 individuals in each. All exposures were compared to a unexposed laboratory control.
transcription profiling by array
Helen C Poynton <email@example.com>, Alexandre Loguinov, Bonnie J Blalock, Christopher A Impellitteri, H J Allen, J Heckman, James M Lazorchak, Kim Rogers, Shekar Govindasmawy