Project description:We measured the mRNA abundance in E.coli using RNAseq to calculate mRNA lifetimes. The data is used in support of a larger paper on the proteome and transcriptome of E.coli.
Project description:A genome reduced E. coli strain MDS42M-NM-^TgalK::Ptet-gfp-kan were applied for the comparative transcriptome analysis. Genome-wide transcriptional changes under high osmotic prresure, high temperature condition and starvation were evaluated. Exponentially growing cells from recoverying stress response were collected for the transcriptome analysis. High osmotic prresure, high temperature condition and starvation were chosen as stressor. In each kind of stress, three level of stresses were applied. Every 3 biological replications were performed.
Project description:Microbes exhibit short and long term responses when exposed to challenging environmental conditions. To what extent these responses are correlated, what their evolutionary potential is and how they translate to cross-stress fitness is still unclear. In this study, we comprehensively characterized the response of Escherichia coli populations to four abiotic stresses (n-butanol, osmotic, acidic, and oxidative) and their combinations by performing genome-scale transcriptional analysis and growth profiling. We performed an analysis of their cross-stress behavior which identified 15 cases of cross- protection and one case of cross vulnerability. To elucidate the evolutionary potential of stress responses to individual stresses and stress combinations, we re-sequenced E. coli populations evolved in those four environments for 500 generations. We developed and applied a network-driven method that integrates mutations and differential expression to identify core and stress-specific gene communities that are likely to have a phenotypic impact. Our results suggest that beyond what is expected from the general stress response mechanisms, cross-stress behavior arises both from common pathways, several including metal ion binding and glycolysis/gluconeogenesis, and stress-specific expression programs. The stress-specific dependences uncovered, argue that cross-stress behavior is ubiquitous and central to understanding microbial physiology under stressful conditions.
Project description:S. cerevisae cells were exposed to different series of mild stresses. Stress type include heat shock, oxidative and osmotic stresses. Microarrays were used to follow the genome-wide transcriptional response to the stresses and to identify genes that can underlie the cross protection phenotype between heat shock and oxidative stress. Keywords: time course
Project description:Plant responses to abiotic stresses are accompanied by massive changes in transcriptome composition. To provide a comprehensive view of stress-induced changes in the Arabidopsis thaliana transcriptome, we have used whole-genome tiling arrays to analyze the effects of salt, osmotic, cold and heat stress as well as application of the hormone abscisic acid (ABA), an important mediator of stress responses.
Project description:Environmental stresses such as drought, heat and salinity limit plant development and agricultural productivity. While individual stresses have been studied extensively, much less is known about the molecular interaction of responses to multiple stresses. To address this problem, we investigated molecular responses of Arabidopsis thaliana to single, double, and triple combinations of salt, osmotic, and heat stresses. A metabolite profiling analysis indicated the production of specific compatible solutes depending on the nature of the stress applied. We found that in combination with other stresses, heat has a dominant effect on global gene expression and metabolites level patterns. Treatments that include heat stress lead to strongly reduced transcription of genes coding for abundant photosynthetic proteins and proteins regulating the cell life cycle, while genes involved in protein degradation are upregulated. Under combined stress conditions, the plants shifted their metabolism to a survival state characterized by low productivity. Our work provides molecular evidence for the dangers for plant productivity and future world food security posed by heat waves resulting from global warming. We highlight candidate genes, many of which are functionally uncharacterized, for engineering plant abiotic stress tolerance.
Project description:Escherichia coli release Extracellular Vesicles (EVs) which carry diverse molecular cargo. Pathogenic E.coli EVs contain virulence factors which assist during infection in the host in different mechanisms.The RNA cargo of E.coli EVs has not been assessed in their effect in the host. We used microarray data to asses and compare the global response of bladder cells to EV-RNA from pathogenic E.coli (Uropathogenic UPEC 536) and non-pathogenic E. coli (probiotic Nissle 1917)
Project description:In the present study, we investigated the transcriptional expression patterns of the model strain E. coli exposed to titanium dioxide nanoparticles (NP-TiO2), under dark conditions by using a microarray. Expression profiles were compared to unexposed E.coli and ratio of expression were analysed.
Project description:We probed the mechanism of cross-regulation of osmotic and heat stress responses by characterizing the effects of high osmolarity (0.3M vs. 0.0M NaCl) and temperature (43oC vs. 30oC) on the transcriptome of Escherichia coli K12 using E. coli Genome 2 Array (Affymetrix, Inc.). Independent array hybridizations were carried out for 3 biological replicates (independent cultures). Total RNA was extracted using a hot phenol-chloroform method. cDNA synthesis, fragmentation and labeling, and washing and scanning of E. coli GeneChip Arrays were performed according to the instructions of the manufacturer (Affymetrix Technical Manual, Affymetrix, Inc., USA). Labeled cDNA was hybridized to E. coli Genome 2 Array (Affymetrix, Inc.). Independent array hybridizations were carried out for 3 biological replicates (independent cultures) of each condition. A number of genes in the SoxRS and OxyR oxidative stress regulons were up-regulated by high osmolarity, high temperature, and/or by the combination of both stresses. This result could account for cross-protection of osmotic stress against oxidative stress. The trehalose biosynthetic genes were induced by both stresses, in accord with the proposed protective role of this disaccharide against thermal and oxidative damage. Keywords: Affymetrix microarrays