Project description:In mammalian tissues circadian gene expression can be driven by local oscillators or systemic signals controlled by the master pacemaker in the suprachiasmatic nucleus. Here we show that simulated body temperature cycles, but not peripheral oscillators, can control the rhythmic expression of Cold-Inducible RNA binding Protein (CIRP) in cultured fibroblasts. In turn, loss-of-function experiments indicate that CIRP is required for high amplitude circadian gene expression. The transcriptome-wide identification of CIRP-bound RNAs by a biotin-streptavidin based CLIP-seq procedure revealed several CIRP-bound transcripts encoding circadian oscillator proteins. One of these, CLOCK, accumulated to particularly low levels in CIRP-depleted fibroblasts. Since ectopic expression of CLOCK improved circadian gene expression in these cells, we surmise that CIRP confers robustness to circadian oscillators via the regulation of CLOCK expression.
Project description:We analysed the effect of cold priming on cold and high light regulation of gene expression. 5 days after the first cold treatment the primary stress response was widely reset. Then, a second (triggering) cold stimulus (24 h 4 °C) and a triggering high-light stimulus (2 h 800 µmol quanta m-2 s-1), which regulate many stress responsive genes in the same direction in naïve plants, caused widely specific and even inverse regulation of priming-responsive genes.
Project description:Characterization of RCI1A role in the control of the response to low temperature of cold induced genes. Two-condition experiment, rci1a vs. WT plants. Biological replicates: 3 aclimated and 3 control replicates.
Project description:In mammalian tissues circadian gene expression can be driven by local oscillators or systemic signals controlled by the master pacemaker in the suprachiasmatic nucleus. Here we show that simulated body temperature cycles, but not peripheral oscillators, can control the rhythmic expression of Cold-Inducible RNA binding Protein (CIRP) in cultured fibroblasts. In turn, loss-of-function experiments indicate that CIRP is required for high amplitude circadian gene expression. The transcriptome-wide identification of CIRP-bound RNAs by a biotin-streptavidin based CLIP-seq procedure revealed several CIRP-bound transcripts encoding circadian oscillator proteins. One of these, CLOCK, accumulated to particularly low levels in CIRP-depleted fibroblasts. Since ectopic expression of CLOCK improved circadian gene expression in these cells, we surmise that CIRP confers robustness to circadian oscillators via the regulation of CLOCK expression. Identification of CIRP-interacting RNA molecules in NIH3T3 cells and RNA expression in NIH3T3 cells treated with Control or CIRP siRNA after incubation of the cells at 33M-BM-0C for 8 hours
Project description:We analysed the effect of a short 24 hours cold exposure (priming-stimulus) on gene regulation upon the first two hours of a second cold (4°C) stimulus (cold-triggering) and upon the first two hours of excess light exposure (800 µmol photons m-2 s-1, light triggering). The first and the second stress treatment was seperated by 5 days long lag-phase, which is long enough to reset most of the primary stress response. Several early light and early cold responsive genes showed however a altered transcript abundance in plants, which received five days befor the cold priming stimulus. Espicially JA responsive genes showed a common priming regulation within the cold and light exposure.
Project description:In mammals body temperature fluctuates diurnally around a mean value of 36-37°C. Despite the small differences between minimal and maximal values, body temperature rhythms can drive robust cycles in gene expression in cultured cells and, likely, in, animals. Here we studied the mechanisms responsible for the temperature-dependent expression of Cold- Inducible RNA-Binding Protein (CIRBP). In NIH3T3 fibroblasts exposed to simulated mouse body temperature cycles Cirbp mRNA oscillates about 3-fold in abundance, as it does in mouse liver. This daily mRNA accumulation cycle is directly controlled by temperature oscillations and does not depend on the cells’ circadian clocks. Here, we show that the temperature-dependent accumulation of Cirbp mRNA is controlled primarily by the regulation of splicing efficiency, defined as the fraction of Cirbp pre-mRNA processed into mature mRNA. As revealed by genome-wide “approach-to-steady-kinetics”, this posttranscriptional mechanism is wide-spread in the temperature-dependent control of gene expression.
Project description:To understand the gene network that controls plant tolerance to cold stress, we carried out a near full genome transcript expression profiling in Arabidopsis using Affymetrix GeneChips that contain approximately 24,000 genes. For microarray analysis, Arabidopsis seedlings were cold treated at 0 C for 0 h, 3 h, 6 h, and 24 h. A total of 939 genes were statistically determined to be cold-regulated with 655 being up-regulated and 284 down-regulated. A large number of the early cold-responsive genes encode transcription factors that likely control late-responsive genes, which implies a multitude of transcriptional cascades. In addition, many genes involved in post-transcriptional and chromatin level regulation were also cold regulated suggesting their involvement in cold responsive gene regulation. A number of genes important for the biosynthesis or signaling of plant hormones, such as abscisic acid, gibberellic acid and auxin, are regulated by cold stress, which is of potential importance in coordinating cold tolerance with growth and development. We compared the cold-responsive transcriptomes of wild type and ice1, a mutant defective in an upstream transcription factor required for chilling and freezing tolerance. The transcript levels of many cold-responsive genes were altered in the ice1 mutant not only during cold stress conditions, but also before cold treatments. Our study provides a global picture of the Arabidopsis cold-responsive transcriptome and its control by ICE1, and thus will be valuable for understanding gene regulation under cold stress and the molecular mechanisms of cold tolerance. Keywords: Cold Stress response
Project description:RNA-Seq was performed to study the change of gene expression before and after cold treatment in Brachypodium. Different change patterns were identified. We have provided a complete view of transcriptome under cold stress condition, which will deepen our understanding of gene expression regulation in cold stress response as well as cold stress response mechanism for monocot plants.