The goal of this study is to measure Arabidopsis mRNA transcription and mRNA decay rates genome wide at two temperatures, and thus to calculate the temperature coefficient of both processes. Sensing and response to ambient temperature is important for controlling growth and development of many organisms, in part by regulating mRNA levels. mRNA abundance can change with temperature, but it is unclear whether this results from changes to transcription or decay rates and whether passive or active temperature regulation is involved. Results Using a base analogue labelling method we directly measured the temperature coefficient (Q10) of mRNA synthesis and degradation rates of the Arabidopsis transcriptome. We show that for most genes transcript levels are buffered against passive increases in transcription rates by balancing passive increases in the rate of decay. Strikingly, for temperature-responsive transcripts, increasing temperature raises transcript abundance primarily by promoting faster transcription relative to decay and not vice versa, suggesting a global transcriptional mechanism process exists for the activethat controls of mRNA abundance by temperature/
Direct measurement of transcription rates reveals multiple mechanisms for configuration of the Arabidopsis ambient temperature response.
Specimen part, Treatment, Time
View SamplesMaternal environment is an important regultor of seed dormancy, but the mechanisms underlying the process are poorly understood. We have found that genes in the circadian clock control dormancy, in part through their regulation of the canonical photoperiod pathway known from research into flowering time control. In this experiment we compare the affects of altering seed maturation temperature or maternal photoperiod on dry seed transcriptomes, and the photoperiod-insenstive ft-1 mutant to wt type Ler. In this way we are identifying gene expression programmes which result from the seed's response to maternal environmental experience.
Induction of dormancy in Arabidopsis summer annuals requires parallel regulation of DOG1 and hormone metabolism by low temperature and CBF transcription factors.
Specimen part
View SamplesHere we studied the effects of anticonvulsant drug exposure in a human embryonic stem cell (hESC) based neuro- developmental toxicity test (hESTn). During neural differentiation the cells were exposed, for either 1 or 7 days, to non-cytotoxic concentration ranges of valproic acid (VPA) or carbamazepine (CBZ), anti-epileptic drugs known to cause neurodevelopmental toxicity.
Gene Expression Regulation and Pathway Analysis After Valproic Acid and Carbamazepine Exposure in a Human Embryonic Stem Cell-Based Neurodevelopmental Toxicity Assay.
Time
View SamplesIn an ongoing translational research program involving microarray-based expression profiles in pediatric septic shock, we have now conducted longitudinal studies focused on the temporal expression profiles of canonical signaling pathways and gene networks. Genome-level expression profiles were generated from whole blood-derived RNA samples of children with septic shock (n = 30 individual patients) corresponding to days 1 and 3 of admission to the pediatric intensive care unit. Based on sequential statistical and expression filters, day 1 and day 3 of septic shock were characterized by differential regulation of 2,142 and 2,504 gene probes, respectively, relative to normal control patients. Venn analysis demonstrated 239 unique genes in the day 1 data set, 598 unique genes in the day 3 data set, and 1,906 genes common to both data sets. Analyses targeted toward derivation of biological function from these data sets demonstrated time-dependent, differential regulation of genes involved in multiple canonical signaling pathways and gene networks primarily related to immunity and inflammation. Notably, multiple and distinct gene networks involving T cell- and MHC antigen-related biological processes were persistently downregulated from day 1 to day 3. Further analyses demonstrated large scale and persistent downregulation of genes corresponding to functional annotations related to zinc homeostasis. These data represent the largest reported cohort of patients with septic shock, which has undergone longitudinal genome-level expression profiling. The data further advance our genome-level understanding of pediatric septic shock and support novel hypotheses that can be readily tested at both the experimental and translational levels.
Genome-level longitudinal expression of signaling pathways and gene networks in pediatric septic shock.
No sample metadata fields
View SamplesZebrafish embryos have been proposed as an attractive alternative model system for hepatotoxicity testing.
A transcriptomics-based hepatotoxicity comparison between the zebrafish embryo and established human and rodent in vitro and in vivo models using cyclosporine A, amiodarone and acetaminophen.
Compound
View SamplesIn acute promyelocytic leukemia (APL), differentiation therapy with all-trans retinoic acid (ATRA)
Chemokine induction by all-trans retinoic acid and arsenic trioxide in acute promyelocytic leukemia: triggering the differentiation syndrome.
Specimen part
View SamplesWT J1 and 3B3L cells (in which Dnmt3B and Dnm3L are constitutively expressed from an exogenous construct) were cultured under both serum/LIF and 2i/LIF conditions. 3B3L cells do not show ground state-associated hypomethylation phenotype. This experiment sought to analyse the gene expression changes between the two conditions. Overall design: Three biological replicates per condition J1 serum, J1 2i, 3B3-3l serum, 3B3-3l 2i.
DNA Methylation Directs Polycomb-Dependent 3D Genome Re-organization in Naive Pluripotency.
Specimen part, Cell line, Subject
View SamplesGoal of the experiment: To identify correlated genes, pathways and groups of patients with systemic inflammatory response syndrome and septic shock that is indicative of biologically important processes active in these patients.
Genome-level expression profiles in pediatric septic shock indicate a role for altered zinc homeostasis in poor outcome.
No sample metadata fields
View SamplesTFIID is a central player in activated transcription initiation. Recent evidence suggests that the role and composition of TFIID is more diverse than previously understood. To investigate the effects of changing the composition of TFIID in a simple system we depleted TAF1 from Drosophila cells and determined the consequences on metal induced transcription at an inducible gene, Metallothionein B (MtnB). We observe a marked increase in the levels of both the mature message and pre-mRNA in TAF1 depleted cells. Under conditions of continued metal exposure, we show that TAF1 depletion increases the magnitude of the initial transcription burst, but has no effect on the timing of that burst. We also show that TAF1 depletion causes delay in the shut-off of transcription upon removal of the stimulus. Thus TAFs are involved in both establishing an upper limit of transcription during induction and efficiently turning the gene off once the inducer is removed. Using genomewide nascent-seq we identify hundreds of genes that are controlled in a similar manner indicating that the findings at this inducible gene are likely generalizable to a large set of promoters. There is a long-standing appreciation for the importance of the spatial and temporal control of transcription. Here we uncover an important third dimension of control, the magnitude of the response. Our results show that the magnitude of the transcriptional response to the same signaling event, even at the same promoter, can vary greatly depending on the composition of the TFIID complex in the cell. Overall design: Nascent RNA was sequenced from replicate samples of Drosophila S2 cells treated with double-stranded RNA directed against E. coli LacI (Control) or against Drosophlia TAF1 (experimental). Reads per kilo-base per million (RPKM) was determined for each gene and the control and experimental samples were compared to determine the genes that were affected by the depletion of TAF1.
Holo-TFIID controls the magnitude of a transcription burst and fine-tuning of transcription.
Specimen part, Subject
View SamplesBACKGROUND. Human prostate cancer LNCaP and PC-3 cell lines have been extensively used as prostate cancer cell models to study prostate cancer progression and to develop therapeutic agents. Although LNCaP and PC-3 cells are generally assumed to represent early and late stages of prostate cancer development, respectively, there is limited information regarding comprehensive gene expression patterns between these two cells lines and relating these cells to prostate cancer progression based on their gene expression.
Unique patterns of molecular profiling between human prostate cancer LNCaP and PC-3 cells.
No sample metadata fields
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