Project description:Custom D. magna gene expression microarray (Design ID: 023710, Agilent Technologies)were used to characterise gene expression profiles of Daphnia magna neoantes exposed to silver nanoparticles ( AgNPs ) or silver nitrate ( AgNO3 ) for 24 hours.
Project description: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.
Project description:In the past years, the research focus on the effects of microplastics (MP) on aquatic organisms extended from marine systems towards freshwater systems. An important freshwater model organism in the MP field is the cladoceran Daphnia, which plays a central role in lacustrine ecosystems and has been established as a test organism in ecotoxicology. To investigate the effects of MP on Daphnia magna, we performed a chronic exposure experiment with polystyrene MP under strictly standardized conditions. Chronic exposure of D. magna to PS microparticles led to a significant reduction in body length and number of offspring. To shed light on underlying molecular mechanisms induced by microplastic ingestion in D. magna, we assessed the effects of PS-MP at the proteomic level.
Project description:This SuperSeries is composed of the following subset Series: GSE29854: Daphnia magna exposed to narcotics and polar narcotics - aniline GSE29856: Daphnia magna exposed to narcotics and polar narcotics - 4-chloroaniline GSE29857: Daphnia magna exposed to narcotics and polar narcotics - 3,5-dichloroaniline GSE29858: Daphnia magna exposed to narcotics and polar narcotics - 2,3,4-trichloroaniline GSE29862: Daphnia magna exposed to narcotics and polar narcotics - ethanol GSE29864: Daphnia magna exposed to narcotics and polar narcotics - isopropanol GSE29867: Daphnia magna exposed to narcotics and polar narcotics - methanol Refer to individual Series
Project description: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.
Project description:Transcriptomics studies are more likely to achieve predictive results when they rely on tissue- and cell-specific transcriptional data. Identification of cell types in novel model organisms by their transcriptional profiles is difficult without data on transcriptional differences among major tissues and anatomical features. Here we report the first dataset on tissue- and organ-specific transcriptomics in freshwater plankton crustacean Daphnia magna, reporting markers of eggs, hemocytes, gut, carapace, antennae and head (as well as the remaining carcass).
Project description:We determined lithium cobalt oxide LCO’s effects on pathways in the model organism Daphnia magna through RNA-Seq global gene expression analysis.