Transcriptional response of Ostreococcus tauri to Cu challenge
Ontology highlight
ABSTRACT: We test the transcriptional response of O. tauri RCC745 cells to two different copper concentration (0,4 and 2 µM), after 1, 4 and 12 h of copper amendments.
Project description:cDNA macroarray expression profiling was carried out in poplar roots in order to identify genes regulated in response to exposition to copper stress. For this purpose, plants of a Populus deltoides clone grown in a hydroponic system during four weeks were incubated in a nutrient solution (Hoagland's modiefied salt, ¼ strength) supplemented with copper (0 µM (control), 30 µM and 60 µM). Roots were sampled at 12 and 24 h after exposition in a time-course experiment.
Project description:The gene expression profile of E. coli K-12 MG1655 grown in minimal medium supplemented with elevated copper concentrations (as copper-glycine) has been analysed using whole genome oligonucleotide microarrays. “Pool” RNA was isolated from five independently grown 50ml DMA cultures of E. coli K-12 MG1655. “Test” RNA was isolated from three independently grown 50ml DMA cultures of E. coli K-12 MG1655, for each growth condition (no added CuSO4, or supplemented with either 0.75mM or 2mM copper glycine). A sample of each culture was taken at mid to late exponential growth phase at OD600 0.8 (measured using a Pharmacia Biotech Ultrospec 2000 in a cuvette with a path length of 10mm). Keywords: dose response
Project description:The cyanobacterium Microcystis aeruginosa PCC 7806 was used for a systematic survey of the relationship between copper and microcystins synthesis. Here we have used microarrays to interrogate the global responses to copper additions at 0.5 micromolar (µM) and 3 µM of copper. From the gene level, microarray studies (3 µM copper supplementation) showed effects on iron, sulfur, glutaredoxin and dehydratase homeostasis gene expression. However, in 0.5 µM groups, those genes that significantly enriched in 3 µM groups regulatory were not all found. In the microarray data for copper stress (3 µM) revealed a broad effect on the expression of iron-sulphur cluster associated pathways, such as cysteine biosynthesis. All of these data indicate that Fe / S cluster biogenesis and/or repair were affected by copper in M. aeruginosa.
Project description:Genome wide rhythmic transcription under light/dark cycles is associated with sequential transcription of specific biological processes genes in Ostreococcus tauri. Transcriptional profiling of Ostreococcus tauri under light/dark cycles. In order to identify genes with a diurnal rhythm, cells entrained under 12:12 light/dark cycles were sampled every 3 hours for 27 hours with two overlapping time points at Time 9 (Light ON at Time 9; Light OFF at Time 21) in 3 independent experiments. Two-conditions experiment, test situation (kinetic point) vs. Pool of each samples. Biological triplicates: 3 independant kinetics, 9 points per kinetics, Technical triplicates per array.
Project description:Despite the increased utilization of nanoparticles, the behavior and effect in the environment is largely unknown and few resources are available for health and environmental effect studies. Enchytraeids are extensively used in studies of soil ecotoxicology and recently, a cDNA microarray for Enchytraeus albidus was developed, allowing also toxicogenomic studies in this species. These organisms are ecologically relevant small worms that indirectly contribute to the regulation and degradation of organic matter. In this study we compared the gene expression profiles of E. albidus when exposed to copper-salt (CuCl2) and copper nanoparticles (Cu-NP) spiked soil. The worms were exposed for 48 hours in soil to a range of concentrations. Microarray hybridizations revealed different response patterns between copper-salt and copper nanoparticles exposed organisms, these differences are mainly related with transcripts involved in the energy metabolism of the organisms. Despite unknown gene function in the data-set there are indications that Cu-salt and Cu-NP exposure induced specific gene level responses.
Project description:Genome wide rhythmic transcription under light/dark cycles is associated with sequential transcription of specific biological processes genes in Ostreococcus tauri. Transcriptional profiling of Ostreococcus tauri under light/dark cycles. In order to identify genes with a diurnal rhythm, cells entrained under 12:12 light/dark cycles were sampled every 3 hours for 27 hours with two overlapping time points at Time 9 (Light ON at Time 9; Light OFF at Time 21) in 3 independent experiments.
Project description:A 3 x 2 factorial design was used to elucidate the genome-wide transcriptional response to the deletion of yeast ortholog of Wilson and Menkes disease causing gene; CCC2, at changing copper levels. Homozygous deletion mutant of CCC2, which encodes Cu+2 transporting P-type ATPase required to export copper from the cytosol into the extracytosolic compartment, and the reference strain were cultivated in fully controlled fermenters in duplicates in glucose-rich defined medium containing three different levels of copper. The three different copper concentrations were selected such that; copper deficient condition, which was prepared by excluding the CuSO4.7H2O from the defined medium, low copper or adequate copper concentration, which is the standard amount of copper in defined medium (0.04 ?M) and high copper concentration (0.5 mM), which was able to restore respiration deficiency in ccc2?/ccc2? strain.
Project description:The present work describes the effects on iron homeostasis when copper transport was deregulated in Arabidopsis thaliana by overexpressing copper transporters (COPTOE). A genome-wide analysis conducted on COPT1OE plants, highlighted that iron homeostasis gene expression was affected, both under copper deficiency and excess. Among the inhibited genes were those encoding the iron uptake machinery and their transcriptional regulators. Subsequently, COPTOE seedlings contained less iron and were more sensitive than controls to iron deficiency. These results emphasized the importance of appropriate spatiotemporal copper uptake for iron homeostasis under copper deficiency. The deregulation of copper-I uptake difficulted the transcriptional activation of the subgroup Ib of basic helix-loop-helix (bHLH-Ib) factors. Oppositely, copper excess inhibited the expression of the master regulator FIT but activate bHLH-Ib expression in COPTOE plants, in both cases leading to the lack of an adequate iron uptake response. As copper increased in the media, iron-III was accumulated in roots, accounting for a defective iron mobilization to the aerial parts, and this effect was exacerbated in COPTOE plants. Thus, iron-III overloading in roots inhibited local iron deficiency responses, aimed to metal uptake from soil, leading to a general lower iron content in the COPTOE seedlings. The understanding of the role of copper uptake in iron metabolism could be applied for increasing crops resistance to iron deficiency
Project description:Despite the increased utilization of nanoparticles, the behavior and effect in the environment is largely unknown and few resources are available for health and environmental effect studies. Enchytraeids are extensively used in studies of soil ecotoxicology and recently, a cDNA microarray for Enchytraeus albidus was developed, allowing also toxicogenomic studies in this species. These organisms are ecologically relevant small worms that indirectly contribute to the regulation and degradation of organic matter. In this study we compared the gene expression profiles of E. albidus when exposed to copper-salt (CuCl2) and copper nanoparticles (Cu-NP) spiked soil. The worms were exposed for 48 hours in soil to a range of concentrations. Microarray hybridizations revealed different response patterns between copper-salt and copper nanoparticles exposed organisms, these differences are mainly related with transcripts involved in the energy metabolism of the organisms. Despite unknown gene function in the data-set there are indications that Cu-salt and Cu-NP exposure induced specific gene level responses. Fluorescently labelled cDNA, from enchytraeids exposed during 2 days to control soil (from Hygum site in Denmark) and to the different exposure conditions (Cy5), was synthesized for microarray analysis and hybridizations were performed. After scanning, spots were identified and ratios quantified using the QuantArray (Packard Biochip Technologies). Statistical analysis of the microarrays was performed using limmaGUI package (1.18.0) (Smyth, 2005) in the R (2.8.0) software environment (http://www.R-project.org/). After being submitted to local background subtraction, microarrays were normalized using global loess method. To statistically evaluate the differential gene expression between the different conditions, a gene-per-gene linear model (limma – linear model for microarray analysis) and empirical Bayes methods were applied. The results were then corrected for multiple testing using the Benjamini-Hochberg’s method (adjusted p<0.05 was considered significant) (Benjamini and Hochberg, 1995).