Daphnia magna
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA95571 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:To determine toxicant specific effects of Ordnance Related Compound (ORC) exposure we performed microarray hybridizations with RNA isolated from Daphnia magna following different ORC exposures at the 1/10 LC50. The gene expression profiles revealed toxicant specific gene expression profiles allowed for the identification of specific biomarkers of exposure. Keywords: ecotoxicogenomic exposure study We exposed Daphnia magna the 1/10 LC50 of different Ordnance Related Compounds (Cu, Zn, Pb, WO4, RDX, TNT, 2-ADNT, 2-ADNT, TNB, DNB, 2,4-DNT, and 2,6-DNT) for 24 hours. For each exposure condition, we performed 3 exposures and 2 technical replicates (as dye swap) for each exposure (6 microarrays total, except TNT and Cu). All exposures were compared to a unexposed laboratory control (MHRW media).
2010-05-18 | E-GEOD-13169 | biostudies-arrayexpress
Project description:To determine toxicant specific effects of Ordnance Related Compound (ORC) exposure we performed microarray hybridizations with RNA isolated from Daphnia magna following different ORC exposures at the 1/10 LC50. The gene expression profiles revealed toxicant specific gene expression profiles allowed for the identification of specific biomarkers of exposure. Keywords: ecotoxicogenomic exposure study
2008-10-16 | GSE13169 | GEO
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: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.
2012-08-04 | E-GEOD-35150 | 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-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:Cadmium (Cd) is a toxic metal causing sublethal and chronic effects in crustaceans. Omic technologies offer unprecedented opportunities to better understand modes of toxicity by providing a holistic view of the molecular changes underlying physiological disruption. We sought to use gene expression and metabolomic analyses to reveal the processes leading to chronic Cd toxicity in the indicator species, Daphnia magna, after a 24-h sublethal exposure (18 ug/L, corresponding to 1/10 LC50). We first confirmed that metabolites can be detected and identified in small volumes (~3-6 ul) of D. magna hemolymph using Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry and NMR spectroscopy. We then compared the altered metabolite levels from a mass spectrometry metabolomics study to differentially expressed genes identified by a D. magna 44k oligonucleotide microarray. Metabolomics identified several essential amino acids, nucleotides and fatty acids as decreased in D. magna hemolymph following Cd exposure. Transcriptional changes included decreased levels of digestive enzymes and increased expression of genes related to embryonic development. The integration of metabolomic and transcriptomic profiles, as well as incorporation of results from previous studies, has enabled construction of a conceptual model detailing how sublethal Cd disrupts energy reserves and reproduction resulting in chronic toxicity. Daphnia magna were exposed to 18 micrograms/L Cadmium sulfate for 24 hours. RNA was extracted and hybridized to a custom Daphnia magna microarray to determine genes differentially expressed by the treatment. Two treament experiment:Unexposed and Cd treatment, 6 replicates for each condition
2010-12-31 | E-GEOD-20218 | biostudies-arrayexpress
Project description:Gene expression profiles of Daphnia magna exposed to Cd at the 1/10 LC50
| PRJNA124143 | ENA
Project description:Gene expression profiling in Daphnia magna, Part III: Uncovering Biomarkers for Metal and ORC exposures
| PRJNA109639 | ENA
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