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:Transcriptomic profilling of 4 daphnia magna clones. One laboratory clone (Clone F +/+), one heterozygotic Clone (Clone 13 +/-) , two homozygotic Clones (Clone 16 and 17 -/-)
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.
Project description:Comparison of female and male Daphnia magna gene expression with age. The sexes in Daphnia magna are genetically identical. The aim of this study was to identify possible differences in gene expression between genders with age.
Project description:Epigenetic mechanisms have been found to play important roles in environmental stress response and regulation. These can, theoretically, be transmitted to future unexposed generations, yet few studies have shown persisting stress-induced transgenerational effects, particularly in invertebrates. Here, we focus on the aquatic microcrustacean Daphnia, a parthenogenetic model species, and its response to salinity stress. Salinity is a serious threat to freshwater ecosystems and a relevant form of environmental perturbation affecting freshwater ecosystems. We exposed one generation of D. magna to high levels of salinity (F0) and found that the exposure provoked specific methylation patterns that were transferred to the three consequent non-exposed generations (F1, F2 and F3). This was the case for the hypomethylation of six protein-coding genes with important roles in the organisms’ response to environmental change: DNA damage repair, cytoskeleton organization and protein synthesis. This suggests that epigenetic changes in Daphnia are particularly targeted to genes involved in coping with general cellular stress responses. Our results highlight that epigenetic marks are affected by environmental stressors and can be transferred to subsequent unexposed generations. Epigenetic marks could therefore prove to be useful indicators of past or historic pollution in this parthenogenetic model system. Furthermore, no life history costs seem to be associated with the maintenance of hypomethylation of across unexposed generations in Daphnia following a single stress exposure.
Project description:This experiment was conducted to study the short-term (12h) transcriptional responses in Daphnia magna after exposure to the anti-sea lice chemical emamectin benzoate (EMB). The microarray results were further vefiried using qPCR. The gene exression responses were linked to adverse effects after 48h exposure, in order to supply knowledge for environmental hazard assessment of this chemical in non-target crustaceans. Neonatal (<24h) Daphnia magna were exposed to 7.8-2000 pM waterborne emamectin benzoate for 12h. Microarray analysis was performed using pooled whole-organism D. magna (8 individuals) and 4 biological replicates were analyzed for each treatment group.
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