Daphnia magna
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA128983 | ENA |
REPOSITORIES: ENA
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Project description:There is still a lot of contradiction on whether metal ions are solely responsible for the observed the toxicity of ZnO and CuO nanoparticles to aquatic species. While most tests have studied nanoparticle effects at organismal levels (e.g. mortality, reproduction), effects at suborganismal levels may clarify the role of metal ions, nanoparticles and nanoparticle aggregates. In this study, the effect of ZnO, CuO nanoparticles and zinc, copper salts was tested on the gene expression levels in Daphnia magna. D. magna was exposed during 96 hours to 10% immobilization concentrations of all chemicals, after which daphnids were sampled for a differential gene expression analysis using microarray. When comparing the nanoparticle exposed daphnids (ZnO or CuO) to the metal salt exposed daphnids (zinc or copper salt), the microarray results showed no significantly differentially expressed genes. These results indicate that the toxicity of the tested ZnO and CuO nanoparticles to D. magna caused is solely caused by toxic metal ions. 4 replicate exposures of ZnO nanoparticles, ZnCl2, Blank (for Zn); 4 replicate exposures of CuO nanoparticles, CuCl2.2H2O, Blank (for Cu); Individual reference design with swapped dyes for zinc (e.g. ZnO-REFZn; REFZn-bl) and copper exposure (e.g. CuO-REFCu; REFCu-bl); Zinc reference sample is a mixture of equal aliquots of ZnO nanoparticle, ZnCl2 and blank; Copper reference sample is a mixture of equal aliquots of CuO nanoparticle, CuCl2.2H2O and blank
2014-03-01 | E-GEOD-54738 | biostudies-arrayexpress
Project description:There is still a lot of contradiction on whether metal ions are solely responsible for the observed the toxicity of ZnO and CuO nanoparticles to aquatic species. While most tests have studied nanoparticle effects at organismal levels (e.g. mortality, reproduction), effects at suborganismal levels may clarify the role of metal ions, nanoparticles and nanoparticle aggregates. In this study, the effect of ZnO, CuO nanoparticles and zinc, copper salts was tested on the gene expression levels in Daphnia magna. D. magna was exposed during 96 hours to 10% immobilization concentrations of all chemicals, after which daphnids were sampled for a differential gene expression analysis using microarray. When comparing the nanoparticle exposed daphnids (ZnO or CuO) to the metal salt exposed daphnids (zinc or copper salt), the microarray results showed no significantly differentially expressed genes. These results indicate that the toxicity of the tested ZnO and CuO nanoparticles to D. magna caused is solely caused by toxic metal ions. 4 replicate exposures of ZnO nanoparticles, ZnCl2, Blank (for Zn); 4 replicate exposures of CuO nanoparticles, CuCl2.2H2O, Blank (for Cu); Individual reference design with swapped dyes for zinc (e.g. ZnO-REFZn; REFZn-bl) and copper exposure (e.g. CuO-REFCu; REFCu-bl); Zinc reference sample is a mixture of equal aliquots of ZnO nanoparticle, ZnCl2 and blank; Copper reference sample is a mixture of equal aliquots of CuO nanoparticle, CuCl2.2H2O and blank
2014-03-01 | E-GEOD-54736 | biostudies-arrayexpress
Project description:Zinc Oxide nanoparticles (ZnO NPs) are being rapidly developed for use in consumer products, wastewater treatment and chemotherapy providing several possible routes for ZnO NP exposure to humans and aquatic organisms. Recent studies have shown that ZnO NPs undergo rapid dissolution to Zn+2, but the relative contribution of Zn+2 to ZnO NP bioavailability and toxicity is not clear. Gene expression profiling of D. magna exposed to ZnO NPs or ZnSO4 at equitoxic concentrations demonstrated that the particles cause toxicity through a distinct mechanism compared with Zn+2. D. magna were also exposed to a SiO NPs as a particle control at equimolar concentrations. The SiO NPs resulted in few differentially expressed genes and there was very little overlap between the genes affected by the ZnO NPs and the SiO NPs, suggesting that ZnO NPs cause a distinct pattern of differentially expressed genes. In the ZnO NP exposures, effects were observed to genes involved in cytoskeletal transport, cellular respiration and reproduction. Three biomarker genes including a multi-cystatin, ferritin and a C1q containing gene were confirmed as differentially expressed in a specific pattern by ZnO NP and provide a suite of biomarkers for identifying environmental exposure to ZnO NP and differentiating between NP and ionic exposure. We exposed Daphnia magna to the 1/10 LC50 and LC25 of ZnO nanoparticles and Zn++ as ZnSO4 for 24-h. For each exposure condition, we performed 3 exposures and 2 technical replicates (as dye swap) for each exposure (6 microarrays total). All exposures were compared to a unexposed laboratory control
2010-12-31 | E-GEOD-22051 | biostudies-arrayexpress
Project description:There is still a lot of contradiction on whether metal ions are solely responsible for the observed the toxicity of ZnO and CuO nanoparticles to aquatic species. While most tests have studied nanoparticle effects at organismal levels (e.g. mortality, reproduction), effects at suborganismal levels may clarify the role of metal ions, nanoparticles and nanoparticle aggregates. In this study, the effect of ZnO, CuO nanoparticles and zinc, copper salts was tested on the gene expression levels in Daphnia magna. D. magna was exposed during 96 hours to 10% immobilization concentrations of all chemicals, after which daphnids were sampled for a differential gene expression analysis using microarray. When comparing the nanoparticle exposed daphnids (ZnO or CuO) to the metal salt exposed daphnids (zinc or copper salt), the microarray results showed no significantly differentially expressed genes. These results indicate that the toxicity of the tested ZnO and CuO nanoparticles to D. magna caused is solely caused by toxic metal ions.
2014-03-01 | GSE54738 | GEO
Project description:There is still a lot of contradiction on whether metal ions are solely responsible for the observed the toxicity of ZnO and CuO nanoparticles to aquatic species. While most tests have studied nanoparticle effects at organismal levels (e.g. mortality, reproduction), effects at suborganismal levels may clarify the role of metal ions, nanoparticles and nanoparticle aggregates. In this study, the effect of ZnO, CuO nanoparticles and zinc, copper salts was tested on the gene expression levels in Daphnia magna. D. magna was exposed during 96 hours to 10% immobilization concentrations of all chemicals, after which daphnids were sampled for a differential gene expression analysis using microarray. When comparing the nanoparticle exposed daphnids (ZnO or CuO) to the metal salt exposed daphnids (zinc or copper salt), the microarray results showed no significantly differentially expressed genes. These results indicate that the toxicity of the tested ZnO and CuO nanoparticles to D. magna caused is solely caused by toxic metal ions.
2014-03-01 | GSE54736 | GEO
Project description:Zinc Oxide nanoparticles (ZnO NPs) are being rapidly developed for use in consumer products, wastewater treatment and chemotherapy providing several possible routes for ZnO NP exposure to humans and aquatic organisms. Recent studies have shown that ZnO NPs undergo rapid dissolution to Zn+2, but the relative contribution of Zn+2 to ZnO NP bioavailability and toxicity is not clear. Gene expression profiling of D. magna exposed to ZnO NPs or ZnSO4 at equitoxic concentrations demonstrated that the particles cause toxicity through a distinct mechanism compared with Zn+2. D. magna were also exposed to a SiO NPs as a particle control at equimolar concentrations. The SiO NPs resulted in few differentially expressed genes and there was very little overlap between the genes affected by the ZnO NPs and the SiO NPs, suggesting that ZnO NPs cause a distinct pattern of differentially expressed genes. In the ZnO NP exposures, effects were observed to genes involved in cytoskeletal transport, cellular respiration and reproduction. Three biomarker genes including a multi-cystatin, ferritin and a C1q containing gene were confirmed as differentially expressed in a specific pattern by ZnO NP and provide a suite of biomarkers for identifying environmental exposure to ZnO NP and differentiating between NP and ionic exposure.
2010-12-31 | GSE22051 | GEO
Project description:The effect of ZnO nanoparticles on gene expression patterns in Daphnia magna
| PRJNA237528 | ENA
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.
2016-04-01 | E-MTAB-4041 | biostudies-arrayexpress
Project description:Background: Toxicogenomics provides new opportunities for innovative and proactive approaches to chemical screening, risk assessment, and predictive toxicology. If applied to ecotoxicology, genomics tools could greatly enhance the ability to detect toxicants and understand the modes of toxicity in an environmental setting. However, few studies have yet to illustrate the potential of genomic techniques in ecotoxicology. Objective: Therefore, our objective was to demonstrate the potential utility of gene expression profiling in ecotoxicology using Daphnia magna, a standard aquatic ecotoxicity test organism. Methods: D. magna were exposed to copper, cadmium, and zinc at the 1/10 LC50 for 24 hours. Following each exposure, RNA was isolated, reverse transcribed, and the cDNA was hybridized to a 5000 clone cDNA microarray for D. magna. Differentially expressed cDNAs were sequenced and homology searches revealed each gene product's potential function. Real time PCR was used to verify the differential expression of several genes, and enzyme assays were used to assess the significance of these changes. Results: We identified distinct expression profiles in response to acute copper, cadmium, and zinc exposures and discovered specific biomarkers of exposure including two probable metallothioneins, and a ferritin mRNA with a functional IRE. The gene expression patterns support known mechanisms of metal toxicity and reveal novel modes of action including zinc inhibition of chitinase activity. Conclusions: Using a cDNA microarray for traditional ecotoxicology organism, D. magna, we have identified novel biomarkers of exposure and revealed possible modes of toxicity, providing experimental support for the utility of ecotoxicogenomics. Keywords: comparative toxicant exposure
2006-12-22 | GSE4759 | GEO
Project description:To determine dose-dependent effects of metal exposure we performed microarray hybridizations with RNA isolated from Daphnia magna following Cu, Cd, and Zn exposures over a range of concentrations that included a tolerated concentration, a sublethal concentration, and a highly toxic concentration. The gene expression profiles revealed effects to digestion related genes, immune related genes, metallothioneins, and oxidative stress genes at the higher concentrations. We also observed that the highest concentrations produced less specific gene expression profiles than the lower concentrations suggesting a more general stress response at the higher concentrations. The lowest concentration tested, representing tolerated concentrations of the metals, caused differential expression of only a few genes and were distinct from the expression profiles of the higher concentrations. This result provides support for the presence of a No Observed Transcriptional Effect Level (NOTEL) for metal exposure in D. magna and suggests that gene expression analysis may offer a strategy for distinguishing between toxic and nontoxic concentrations of metals in the environment. Keywords: ecotoxicogenomic exposure study
2008-06-09 | GSE7668 | GEO