Project description:This SuperSeries is composed of the following subset Series: GSE9660: Profiling the transcriptome of Thalassiosira pseudonana under environmentally relevant growth conditions GSE9661: Profiling the transcriptome of Thalassiosira pseudonana under silicon replete and deplete growth Refer to individual Series
Project description:T. pseudonana gene-specific arrays were used for differential gene expression. Seven hundred nine genes were differentially expressed by more than 2-fold (Bayesian t-test, p< 0.001) under at least one growth-limiting condition relative to nutrient-replete conditions. A striking result of the hierarchical cluster analysis was the identification of a common set of genes that were upregulated by both iron and silicon limitation, but no other treatment. Together, these two treatments accounted for about one fourth of all differentially expressed genes but almost two thirds of the differentially expressed novel genes, further emphasizing the distinctive aspects of silicon manipulation in diatoms. Keywords: silicon, stress response, cell wall, iron, temperature, carbon dioxide
Project description:T. pseudonana gene-specific arrays were used for differential gene expression. Seven hundred nine genes were differentially expressed by more than 2-fold (Bayesian t-test, p< 0.001) under at least one growth-limiting condition relative to nutrient-replete conditions. A striking result of the hierarchical cluster analysis was the identification of a common set of genes that were upregulated by both iron and silicon limitation, but no other treatment. Together, these two treatments accounted for about one fourth of all differentially expressed genes but almost two thirds of the differentially expressed novel genes, further emphasizing the distinctive aspects of silicon manipulation in diatoms. We analyzed 6 different sets of arrays from 6 growth conditions. Four biological replicates (=4 arrays) were used for each growth condition.
Project description:T. pseudonana tiling arrays were used to validate gene models and to predict new genes in the genome of this diatom. The tiling array data validated transcription of about 41% (4,653) of the 11,390 computationally predicted genes. An additional 1,132 transcripts were identified that did not correspond to modeled genes with few of these transcripts (<17%) predicted to encode proteins with homology (e-value < 10-05) to publicly available proteins. These newly identified transcripts have an average length of 1,549 bp, comparable to the average length of the computationally derived genes. Whole genome tiling arrays were conducted under silicon replete and deplete growth conditions to identify new genes involved in the synthesis of the diatom silica cell wall. Keywords: silicon, stress response, cell wall
Project description:Transcript levels of all T. pseudonana genes was measured every twelve hours throughout the batch (non-chemostatic) growth of axenic cells grown in large glass bioreactors on a 12hr:12hr dark:light cycle for five days. The data were analyzed to reveal the physiological and regulatory changes that recurred in this diatom when transitioning between dark and light conditions, as well as from exponential phase to stationary, nutrient limited conditions. The longitudinal experiment was performed with two replicates, at 400 and 800ppm CO2.