Project description:We have deep sequenced the small transcriptome of Escherichia coli growing in LB and in MOPS, in exponential and stationary phase, and analyzed the resulting reads by a novel pipeline STARPA (Stable RNA Processing Product Analyzer). Our analysis reveals over 14,000 small transcripts enriched during both growth stages. RNA samples were collected from total RNA pools or from crude ribosome pools and then size selected by electrophoresis to limit the products to 20-300nt.
Project description:MGAS315 is a wild type strain. RNA isolated in exponential phase and stationary phase were compared Keywords: Growth phase comparison
Project description:The transition between exponential and stationary phase is a natural phenomenon for all bacteria and requires a massive readjustment of the bacterial transcriptome. Exoribonucleases are key enzymes in the transition between the two growth phases. PNPase, RNase R and RNase II are the major degradative exoribonucleases in Escherichia coli. We analysed the whole transcriptome of exponential and stationary phases from the WT and mutants lacking these exoribonucleases (Δpnp, Δrnr, Δrnb, and ΔrnbΔrnr). When comparing the cells from exponential phase with the cells from stationary phase more than 1000 transcripts were differentially expressed, but only 491 core transcripts were common to all strains. There were some differences in the number and transcripts affected depending on the strain, suggesting that exoribonucleases influence the transition between these two growth phases differently. Interestingly, we found that the double mutant RNase II/RNase R is similar to the RNase R single mutant in exponential phase while in stationary phase it seems to be closer to the RNase II single mutant. This is the first global transcriptomic work comparing the roles of exoribonucleases in the transition between exponential and stationary phase.
Project description:E. coli RNA was hybridized to tiling arrays to study the pattern of gene expression across the chromosome. 1 sample for stationary phase and 1 for mid-exponential phase
Project description:Ms1 RNA is ~300 nt sRNA that is highly expressed in stationary phase of growth and binds to the RNA polymerase (RNAP) core. We assume that by binding to RNAP, Ms1 could regulate transcription. Our aim was to reveal the most prominent changes in the transcriptome upon entry into stationary phase that might be dependent on Ms1. We performed RNA-seq data to characterize exponential (Ms_WT_exp) and stationary phase (Ms_WT_stat) transcriptome in M. smegmatis in wild type cells. In addition, we compared the transcriptome of the Ms1 knockout cells (Ms_KO_stat) with wild type cells in stationary phase and in exponential phase (Ms_KO_exp).
Project description:RNA-seq of wild type Mycobacterium smegmatis mc2 155 (exponential and stationary phase) and Ms1 deletion strain (exponential and stationary phase)
Project description:Comparison of Bacillus subtilis wild type and cshA mutant at exponential versus stationary phase. Detailed description (other than provided below) of growth conditions, RNA preparation, cDNA synthesis and hybridization conditions can be found in the submitted paper.
Project description:Although proteins and peptides encoded in small open reading frames (ORFs < 100 AA) in microbial genomes can play critical roles as toxins, bacteriocins, transcriptional regulators, signaling molecules, and chaperones, many such ORFs remain annotated as M-bM-^@M-^\hypothetical proteinsM-bM-^@M-^]. In the genome of the hyperthermophilic bacterium, Thermotoga maritima, nearly 2/3 of the 167 small ORFs have no known function. As a strategy for investigating the potential significance of specific small ORFs, growth conditions that could trigger the expression of genes encoding small ORFs were sought. A defined medium supplemented with either 1 or 5 g/L yeast extract was used to track transcriptional response during the transition from exponential to stationary phase. RNA derived from exponential (1E) and stationary (1S) phase cultures grown on 1 g/l yeast extract was compared to RNA derived from exponential (5E) and stationary (5S) phase cultures grown on 5 g/l yeast extract using a four-slide loop design.
Project description:The cold shock proteins belong to a family of RNA binding proteins presenting a highly conserved domain, called cold shock domain (CSD). They are involved in various cellular processes, including adaptation to low temperature, nutritional stress, cell growth and stationary phase. Here we investigate the role of CspC in C. crescentus stationary phase and the molecular mechanisms underlying gene regulation by this protein. A global transcriptional profiling experiment comparing cspC and the wild type strain both at exponential and stationary phases was carried out. The results showed that the absence of cspC affected the transcription of 20 genes at exponential phase and 65 genes at stationary phase. Genes encoding enzymes of the glyoxylate cycle were severely downregulated in the mutant at stationary phase. The stationary phase-induced RNA binding protein CspC has an important role in gene expression at this phase. It is required for the expression of the essential gene sciP, the ECF sigma factor sigU, as well as of the genes for the glyoxylate cycle enzymes and for oxidative stress response.