Project description:Modifications of RNA, known as the epitranscriptome, affect mRNA stability, translation, and splicing in eukaryotes and have implications for developmental processes, cancer, and viral infections. In prokaryotes, however, the landscape of the epitranscriptome is still poorly understood. To address this knowledge gap, we used direct RNA sequencing with Nanopore technology to study RNA modifications in the model bacterium Escherichia coli. With a single sequencing reaction, we were able to simultaneously identify and map most of the known modification types in rRNA, tRNA, and mRNA. Subsequently, a multifaceted approach integrating different algorithms for data analysis, deletion mutants, mass spectrometry, qPCR, and in vitro methylation was implemented to evaluate the presence of m5C and m6A in E. coli. Known m5C and m6A sites in rRNA were confirmed, but these modifications could not be localized in the mRNA. Nevertheless, based on the sequencing data, modifications were found to be enriched in the coding regions of genes associated with general metabolism and RNA processing. This study provides a useful resource for experimental and bioinformatic approaches to gain new insights into post-transcriptional regulation in a prokaryotic model.
Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
Project description:Despite the characterization of many aetiologic genetic changes. The specific causative factors in the development of sporadic colorectal cancer remain unclear. This study was performed to detect the possible role of Enteropathogenic Escherichia coli (EPEC) in developing colorectal carcinoma.
Project description:Escherichia coli exhibits diauxic growth in sugar mixtures due to CRP-mediated catabolite repression and inducer exclusion related to phosphotransferase system enzyme activity. Replacement of the native crp gene with a catabolite repression mutant (referred to as crp*) alleviates diauxic effects in E. coli and enables co-utilization of glucose and other sugars. While previous studies have examined the effects of expressing CRP* mutants on the expression of specific catabolic genes, little is known about the global transcriptional effects of CRP* expression. In this study, we compare the transcriptome of E. coli W3110 (expressing wild-type CRP) to that of mutant strain PC05 (expressing CRP*) in the presence and absence of glucose.
Project description:Study of the mechanisms of RecB mutant terminus DNA loss in Escherichia coli. FX158: WT MG1655 FX35: recB- FX37: ruvAB- FX51: matP- MIC18: recB- sbcD- sbcC- MIC20: recB- ruvAB- MIC24: matP- recB- MIC25: recA- recB- MIC31: sbcB- sbcD- MIC34: recA- recD- MIC40: linear chromosome MIC41: linear chromosome recB- MIC42: matP- ftsKC- MIC43: matP- ftsKC- recB- MIC48: recA- Cells were grown in M9 minimal medium supplemented with 0.4 % glucose to exponential phase (0.2 OD 650 nm). Chromosomal DNA was extracted using the Sigma GenElute bacterial genomic DNA kit. 5 μg of DNA were used to generate a genomic library according to Illumina's protocol. The libraries and the sequencing were performed by the High-throughput Sequencing facility of the I2BC (http://www.i2bc.paris-saclay.fr/spip.php?article399&lang=en, CNRS, Gif-sur-Yvette, France). Genomic DNA libraries were made with the ‘Nextera DNA library preparation kit’ (Illumina) following the manufacturer’s recommendations. Library quality was assessed on an Agilent Bioanalyzer 2100, using an Agilent High Sensitivity DNA Kit (Agilent technologies). Libraries were pooled in equimolar proportions. 75 bp single reads were generated on an Illumina MiSeq instrument, using a MiSeq Reagent kit V2 (500 cycles) (Illumina), with an expected depth of 217X. An in-lab written MATLAB-based script was used to perform marker frequency analysis. Reads were aligned on the Escherichia coli K12 MG1655 genome using BWA software. Data were normalized by dividing uniquely mapping sequence reads by the total number of reads. Enrichment of uniquely mapping sequence reads in 1 kb non-overlapping windows were calculated and plotted against the chromosomal coordinates.
Project description:Up-regulation of motility genes and biosynthesis genes were found in the pck expressing high ATP cell by transcriptome analysis while catabolism genes were down-regulated. Keywords: response depends on intracellular ATP concentration derived by pck or ppc overexpression 1. pck or ppc overexpressing E. coli at early log phase using glucose-minimal medium 2. pck or ppc overexpressing E. coli at chemostat culture (D=0.1 h-1)using LB-glucose medium
Project description:Inorganic polyphosphate (polyP) is synthesized by bacteria in response to various stresses, but the mechanism of its regulation is unknown. Mutants of Escherichia coli lacking the RNA polymerase-binding transcription factor dksA are defective in polyP synthesis after a nutrient limitation stress, and this defect is reversed in a dksA greA mutant. In this work, we used RNA sequencing to compare transcription in wild-type, dksA, and dksA greA strains of E. coli before and after nutrient limitation, to identify genes whose expression pattern correlates with ability to synthesize polyP.
Project description:Nucleic Acid Sequencing for the study of division induced double strand breaks in the terminus region of Escherichia coli cells lacking RecBCD DNA repair enzymes.