RNA-seq analysis of Escherichia coli str. K-12 substr. MG1655
ABSTRACT: Expression profiles of wild-type and SgrR mutant E. coli strains under aMG and 2-DG-induced stress. Expression profiles of E. coli overexpressing SgrS sRNA. Illumina RNA-Seq of total RNA extracted from wild-type, SgrR/SgrS mutant and SgrS overexpressing E. coli strains grown in different conditions.
Project description:We performed whole-genome transcriptomic analyses of the Salmonella Typhimimurium genome during glucose-phosphate stress. In particular, we wanted to elucidate the role of the the small RNA SgrS and protein regulator SgrT in the stress response. Wild-type Salmonella cells, mutants of Salmonella either lacking sgrS or lacking SgrS RNA/ SgrT peptide function were subject to glucose-phoshate stress
Project description:Hundreds of small RNAs (sRNAs) have been identified in diverse bacterial species, and while the functions of most remain unknown, some regulate key processes, particularly stress responses. The sRNA DicF was identified over twenty-five years ago as an inhibitor of cell division, but since then has remained uncharacterized. DicF is 53 nucleotides and is encoded on a prophage (Qin) in the genomes of many Escherichia coli strains. Here, we performed RNA-Seq analyses of an E. coli strain with chromosomal deletion of dicF and overexpressing either empty plasmid or dicF from a plasmid. Systems analysis using computational methods identified additional mRNA targets of DicF: xylR and pykA mRNAs, encoding the xylose uptake and catabolism regulator and pyruvate kinase, respectively. We have further validated these target genes experimentally. RNA-Seq analyses was performed on E. coli strains overexpressing either the vector control or the small RNA DicF.
Project description:We recovered RNA from exponential and stationary phase cell cultures of MGAS2221 and utilized two distinct methods to remove rRNA from our samples, the RiboZero kit from Epicenter, and the terminator- 5--Phosphate-Dependent Exonuclease (TEX). This gave us 4 distinct RNAs with which we performed RNAseq analysis. Both rRNA removal methods worked well, with only a small percentage of the final total read counts being derived from rRNA sequences. A single group A Streptococcus strain was investigated.
Project description:RNA-seq analysis was carried out on N. gonorrhoeae grown in vitro to verify accuracy of a novel RNA-seq analysis program, Rockhopper Three replicates of N. gonorrhoeae grown in vitro
Project description:Bacteria respond to stimuli in the environment using transcriptional control, but this may not be the case for most marine bacteria having small, streamlined genomes. Candidatus Pelagibacter ubique, a cultivated representative of the SAR11 clade, which is the most abundant clade in the oceans 4, has a small, streamlined genome and possesses an unusually small number of transcriptional regulators. This observation leads to the hypothesis that transcriptional control is low in Pelagibacter and limits its response to environmental conditions. However, the extent of transcriptional control in Pelagibacter is unknown. Here we show that transcriptional control is extremely low in Pelagibacter and another oligotroph (SAR92) compared to two marine copiotrophic bacterial taxa, Polaribacter MED152 and Ruegeria pomeroyi. We found that ~0.1% of protein-encoding genes in Pelagibacter are under transcriptional control compared to >10% of genes in other marine bacteria. Regardless of the growth condition, the same genes were highly expressed while most genes were always expressed at very low levels. Quantitative RNA sequencing revealed that abundances of most Pelagibacter transcripts were <0.01 copies per cell whereas transcript abundances were 1 to 10 copies per cell in some other bacteria. Our results demonstrate that Pelagibacter can change growth without shifts in transcript levels, suggesting that transcriptional control plays a minimal role in the adaptive strategy for one of the most successful organisms in the biosphere. Bacteria were grown in batch culture and sampled twice during the initial, rapid phase of exponential growth and twice during the phase of slower growth that followed.
Project description:The goal of this study is to compare gene expression data for a well known model organism (Escherichia coli) using different technologies (NGS here, microarray from GSE48776). mRNA profiles of Wild Type and two Mutant Strains (ydcR (b1439) MUTANT and yjiR (b4340) MUTANT), growth in minimal medium, were generated by deep sequencing, in triplicate, using Illumina MiSeq.
Project description:We show that treatment with HPUra (for S. pneumoniae) and trimethoprim (for E. coli) leads to a skewed gene dosage profile (increase around the origin of replication), which is also propagated to the transcriptome level. Kanamycin, however, does not have this effect. In case of S. pneumoniae this shift in gene dosage distribution leads to the population-wide activation of competence. Pairwise comparison of untreated to antibiotic-treated cells (either DNA-seq or RNA-seq). It was performed with deep sequencing, using an Illumina HiSeq 2000 machine with 100 bp read length. S. pneumoniae samples treated with kanamycin was analysed from a single sample, while all other conditions were from duplicate samples.
Project description:The rapid pace of evolution in bacteria is widely attributed to the promiscuous horizontal transfer and recombination of protein-coding genes. However, it is not known whether the same forces also drive the evolution of non-coding regulatory regions. Here we demonstrate that regulatory region can ‘switch’ between non-homologous alternatives and that such switching is ubiquitous, occurring across the bacterial domain. We show that such regulatory switching strongly impacts promoter architecture and expression divergence. We further show that regulatory transfer facilitates rapid phenotypic diversification of a human pathogen. This regulatory mobility enables bacterial genes to access a vast pool of potential regulatory elements, facilitating efficient exploration of the regulatory landscape. Examination of 2 E. coli strains in 2 conditions
Project description:To identify YehT-regulated genes, the transcriptome profiles of E. coli cells overproducing either the response regulator (RR) YehT or the RR KdpE (control) were comparatively analyzed. The expression level of 32 genes varied more than 8-fold.