Project description:An experiment was performed to determine the similarities on the RNA level between different conditions where cell division stops in the diatom Phaeodactylum tricornutum. Many of these conditions also increase the accumulation of lipids within the cell or impair photosynthesis. The different metabolic responses were evaluated and the dataset was mined for potential transcriptional regulators of these changes. The experimental setup was as follows: Cells from the pennate diatom Phaeodactylum tricornutum were grown in ESAW medium under continous fluorescent light at 21C in baffled shakeflasks. Exponentially growing cells were harvested by centrifugation and washed twice in 21gr/L NaCL to remove nutrients. Cells were subsequently resuspended in the five different media/conditions (control, darkness, no nitrate, no phosphate, nocodazole).
Project description:We have investigated both the response to prolonged darkness and the re-acclimation to “moderate intensity” white irradiance (E = 100 µmol m-2 s-1) in the diatom Phaeodactylum tricornutum, using an integrated approach involving global transcriptional profiling, pigment analyses, imaging and photo-physiological measurements. The responses were studied during continuous white light, after 48 h of dark treatment and after 0.5 h, 6 h, and 24 h of re-exposure to the initial irradiance.
Project description:Diatoms, which are important planktons widespread in various aquatic environments, are believed to play a vital role in primary production as well as silica cycling. The genomes of the pennate diatom Phaeodactylum tricornutum and the centric diatom Thalassiosira pseudonana have been sequenced, revealing some characteristics of the diatomsâ mosaic genome as well as some features of their fatty acid metabolism and urea cycle, and indicating their unusual properties. To identify microRNAs (miRNAs) from P. tricornutum and to study their probable roles in nitrogen and silicon metabolism, we constructed and sequenced small RNA (sRNA) libraries from P. tricornutum under normal (PT1), nitrogen-limited (PT2) and silicon-limited (PT3) conditions. A total of 13 miRNAs were identified. They were probable P. tricornutum-specific novel miRNAs. These miRNAs were differentially expressed in PT1, PT2 and PT3, and their potential targets were involved in various processes. Our results indicated that P. tricornutum contained novel miRNAs that differed from miRNAs of other organisms and that they might play important regulator roles in P. tricornutum metabolism.
Project description:Diatoms played an essential role in marine primary productivity. Polysaccharide chrysolaminarin and neutral lipid, mainly TAG, were necessary carbon fixation in diatom Phaeodactylum tricornutum. Our study speculated on the metabolism pathway of chrysolaminarin, fatty acid, fatty acid β-oxidation and TAG. Transcriptional levels coordinated with carbon fixation metabolism pathway were conjoint analysis in this study.
Project description:Here we use a transcriptomic approach to investigate the molecular underpinnings of thermal acclimation in the model diatom species Phaeodactylum tricornutum by comparing the differential gene expression in cultures acclimated to sub-optimal, optimal, and supra-optimal temperatures (10, 20 and 26.5 °C, respectively).
