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: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:Although it is well established the seasonal effect of the photoperiod over the transcriptional expression patterns in plants, this effect has not been studied in microalgae. Here we fill the gap using the model microalgae Ostreococcus tauri.
Project description:Engineered nanoparticles (ENPs) are increasingly used to generate innovative industrial and medical goods. Because of their broad applications, they form a new class of pollutants with potential eco-toxicological impacts on marine ecosystems. Attempting to evaluate the risk, we investigated the toxicity of Iron and Zinc oxide ENPs on three picophytoplanktonic strains of algae: Micromonas commoda, Ostreococcus tauri and Nannochloris sp. Microalgae responses are highly species-dependent, Micromonas commoda growth being severely impaired by both ENP types whereas Ostreococcus tauri or Nannochloris sp. are resistant. ZnO ENPs have higher toxicity than iron ENPs though growth of M. commoda was severely inhibited by Fe2O3 ENPs. Transcriptome-wide analysis after exposure of M. commoda to ENPs shows that the altered biological processes mainly take place in the cytoplasm and that the response to ENPs is largely metabolic in nature: stimulation of carbohydrate metabolism, light harvesting processes and alteration of the nitrogen pathway. In addition, a severe disruption of ribosome structure and translation processes is observed.
