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: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:We used trimethylpsoralen intercalation to map supercoiling across the E. coli chromosome. We treated E. coli cells with trimethylpsoralen and exposed them to UV light. Psoralen enters cells, intercalates between DNA base pairs, and crosslinks the two strands of DNA at a rate proportional to the local superhelical density. We then fragmented DNA and hybridized crosslinked and non-crosslinked DNA fragments separately to tiling microarrays.
Project description:To determine sites where RpoS binds (and hence likely plays a direct role in transcription), we used ChIP-seq to map the association of RpoS across the Escherichia coli chromosome during stationary phase growth in minimal medium. To facilitate ChIP, RpoS was C-terminally SPA-tagged at its native locus.
Project description:Investigation of whole genome gene expression level in E. coli rpoS knock-out strain grown up to stationary phase in M9 minimal media supplemented with 0.2% glucose E. coli rpoS deletion mutant grown up to OD600nm 1.5 (stationary phase) in M9 minimal media supplemented with 0.2% glucose. The high-density oligonucleotide tiling arrays used were consisted of 371,034 oligonucleotide. Data for wild type controls are GSM389302, GSM389303, and GSM389304.
Project description:Differential expression of genes in E. coli MG1655 strains with deletions of fis and hns was assessed under early-exponential, mid-exponential, transition-to-stationary and stationary phases of growth in LB medium.
Project description:Per- and polyfluoroalkyl substances (PFAS) are highly stable chemical contaminants of emerging concern for human and environmental health due to their non-natural chemistry, widespread use, and environmental persistence. Despite conventional metrology, mitigation strategies, and removal technologies, the complexity of this growing problem necessitates the need for alternative approaches to tackle the immense challenges associated with complex environmental PFAS contamination. Recently, biology has emerged as an alternative approach to detect and mitigate PFAS and understand the molecular-level responses of living organisms, including microorganisms, to these compounds. However, further study is needed to understand how microorganisms in different environments and growth phases respond to PFAS. In this study, we performed RNA sequencing at mid-exponential, early stationary phase, and late stationary phase of bacterial growth to determine the global transcriptional response of a model chassis, Escherichia coli MG1655, induced by two PFAS, perfluorooctanoic acid (PFOA) and perfluorododecanoic acid (PFDoA), and equivalent non-fluorinated carboxylic acids (NFCA), octanoic acid and dodecanoic acid. Differential gene expression analysis revealed PFOA and PFDoA induced distinct changes in gene expression throughout cultivation. Specifically, we identified significant changes in expression of the formate regulon and sulfate assimilation at mid-exponential phase and ferrous iron transport, central metabolism, the molecular chaperone network, and motility processes during stationary phase. Importantly, many of these changes are not induced by NFCAs. In summary, we found PFAS induced a system-level change in gene expression, and our results expand the understanding of bacterial-PFAS interactions that could enable the development of future real-time environmental monitoring and mitigation technologies.
Project description:To compare the transcriptional profiling of a FimZ-expressing strain or non-expressing strain in E. coli under stationary phase. For overexpression of fimZ gene was cloned into pBAD33 plasmid under control of the arabinose-inducible PBAD promoter, which was induced by addition of 0.2% arabinose. Goal was to determine the FimZ regulon in E. coli. Biological replicates: 2 replicates.
Project description:The sensibility of the used low-density arrays was tested by applying the lab strain S. cerevisiae H155. Important abiotic parameters were tested as they were introduced as elevated osmotic, pH or ethanol stress to the cells.
Project description:Quorum signal uptake is an indispensable part of quorum sensing regulations. The coperative regulation of uptake repressor and kinase precisely signale the cells for quorum sensing uptake and terminate the quorum sensing signal production. We use the DNA microarray to detail the E. coli quorum sensing uptake reuglations and related gene regulations. Experiment Overall Design: W3110 wild type and its isogenic mutants lsrR, lsrK's RNA samples were extracted and hybridized for Affymetrix array.