Comparative transcriptomics of Clostridium thermocellum wild type (Î?hpt) and Type I glutamine synthetase (Clo1313_2031) deletion strains using RNA-seq
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ABSTRACT:
ORGANISM(S): Ruminiclostridium thermocellum DSM 1313
SUBMITTER: Dawn Klingeman
PROVIDER: E-GEOD-78219 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Clostridium thermocellum is a candidate for cellulosic ethanol production. It expresses enzymes for both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Understanding how this organism regulates gene expression is of importance for developing a better fundamental understanding of this industrial relevant bacterium. We are primarily interested in gene regulation by three predicted LacI regulators. A previous report of one LacI regulator in C. thermocellum ATCC27405 (Cthe_2808) indicated this was a transcriptional repressor of neighboring genes with repressor activity relieved in the presence of laminaribiose (a β-1,3 disaccharide). The current work is aimed at understanding if a homolog of this LacI transcriptional regulator in C. thermocellum DSM1313 and two others putatively characterized as LacI regulators are in fact global regulatory proteins with extensive regulons or, if like the majority of LacI transcription factors, the regulation is limited to local genomic regions. Each of the three LacI regulators was deleted in C. thermocellum DSM1313. Genome re-sequencing was used to confirm the deletion and ensure nonspecific recombination events were avoided during the gene deletion strategy. Growth of each strain on cellobiose was unaffected by any of the gene deletions under pH controlled fermentations. Global gene expression patterns taken at mid-log phase for each strain identified glycoside hydrolase genes encoding hemicellulases, including cellulosomal enzymes, that were highly up-regulated (up to 9 fold) in the absence of each LacI regulator. Thus suggesting these were repressed under wild type conditions. Electrophoretic mobility shift assays have confirmed LacI transcription factor binding to specific regions of gene promoters with putative motifs ranging from 16-18 bp. Work is ongoing to confirm the specific binding motif recognized by the two previously un-characterized transcription factors and assess the occurrence of this motif in the C. thermocellum DSM1313 genome. The identification of LacI repressor activity on hemicellulose gene expression is a key result of this work and will add to the small body of existing literature on the area of gene regulation in C. thermocellum. Four strains of C. thermocellum DSM1313 including a parental strain (Îhpt) and three others with deletion in lacI transcription factors were characterised by RNA-seq. The strains were grown in 1L bioreactors, cells (from 50 ml samples) were harvested at mid exponential, late exponential and 30 min after acid production halted during the transition to stationary phase. The growth studies were performed in triplicate and thirty six samples were analyzed by RNA-sequencing.
2015-10-31 | E-GEOD-68423 | biostudies-arrayexpress
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.
2016-01-16 | E-GEOD-76916 | biostudies-arrayexpress
Project description:Background: Microorganisms are the major cause of food spoilage during storage, processing and distribution. Pseudomonas fluorescens is a typical spoilage bacterium that contributes to a large extent to the spoilage process of proteinaceous food. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Our previous work revealed that RpoS contributed to the spoilage activities of P. fluorescens by regulating resistance to different stress conditions, extracellular acylated homoserine lactone (AHL) levels, extracellular protease and total volatile basic nitrogen (TVB-N) production. However, RpoS-dependent genes in P. fluorescens remained undefined. Results: RNA-seq transcriptomics analysis combined with quantitative proteomics analysis basing on multiplexed isobaric tandem mass tag (TMT) labeling was performed for the P. fluorescens wild-type strain UK4 and its derivative carrying a rpoS mutation. A total of 375 differentially expressed genes (DEGs) and 212 differentially expressed proteins (DEPs) were identified in these two backgrounds. The DGEs were further verified by qRT-PCR tests, and the genes directly regulated by RpoS were confirmed by 5’-RACE-PCR sequencing. The combining transcriptome and proteome analysis revealed a role of this regulator in several cellular processes, including polysaccharide metabolism, intracellular secretion and extracellular structures, cell well biogenesis, stress responses, ammonia and biogenic amine production, which may contribute to biofilm formation, stress resistance and spoilage activities of P. fluorescens. Moreover, in this work we indeed observed that RpoS contributed to the production of the macrocolony biofilm’s matrix.
2019-11-12 | PXD010845 | Pride
Project description:Both embryonic and adult zebrafish Mycobacterium marinum infection studies have contributed to our knowledge of the development and function of tuberculous granulomas, which are typical for mycobacterial pathogenesis. In this review we discuss how transcriptome profiling studies have helped to characterize this infection process and we include new RNA sequencing (RNA-Seq) data that reveals three main phases in the host response to M. marinum during the early stages of granuloma development in zebrafish embryos and larvae. The late-phase response shares common components with the strong and acute host transcriptome response that has previously been reported for S. typhimurium infection in zebrafish embryos. In contrast, the early/mid-phase response to M. marinum infection, characterized by suppressed pro-inflammatory signaling, is strikingly different from the acute response to S. typhimurium infection. Furthermore, M. marinum infection shows a collective and strongly fluctuating regulation of lipoproteins, while S. typhimurium infection has pronounced effects on amino acid metabolism and glycolysis. Embryos were infected at 28 hpf by injecting 250 colony forming units of M. marinum Mma20 in 2%PVP into the caudal vein, or mock-injected with PBS/2%PVP. After injections, embryos were transferred into fresh egg water containing 0.003% 1-phenyl-2-thiourea (Sigma-Aldrich) to prevent melanization and incubated at 28°C. After the incubation period, infected and uninfected groups of 30 embryos were snap-frozen in liquid nitrogen and RNA was isolated for Illumina RNAseq analysis. Samples were taken at the following timepoints: 2, 4, 6, 8 hpi and 1, 2, 3, 4, 5 dpi.
2016-06-01 | E-GEOD-76499 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2015-04-16 | E-GEOD-66520 | biostudies-arrayexpress
Project description:In a previous study, we found that H2S alleviates salinity stress in cucumber by maintaining the Na+/K+ balance and by regulating H2S metabolism and the oxidative stress response. However, little is known about the molecular mechanisms behind H2S-regulated salt-stress tolerance in cucumber. Here, an integrated transcriptomic and proteomic analysis based on RNA-seq and 2-DE was used to investigate the global mechanism underlying H2S-regulated salt-stress tolerance. In total, 11 761 differentially expressed genes (DEGs) and 61 differentially expressed proteins (DEPs) were identified. Analysis of the pathways associated with the DEGs showed that salt stress enriched expression of genes in primary and energy metabolism, such as photosynthesis, carbon metabolism and biosynthesis of amino acids. Application of H2S significantly decreased these DEGs but enriched DEGs related to plant-pathogen interaction, sulfur-containing metabolism, cell defense and signal transduction pathways. Notably, changes related to sulfur-containing metabolism and cell defense were also observed through proteome analysis, such as Cysteine synthase 1, Glutathione S-transferase U25-like, Protein disulfide-isomerase and Peroxidase 2. We present the first global analysis of the mechanism underlying H2S regulation of salt-stress tolerance in cucumber through tracking changes in the expression of specific proteins and genes.
2021-09-09 | PXD020642 | Pride
Project description:We used zebrafish embryos as an in vivo system to investigate the role of the microRNA-146 family (consisting of 2 members miR-146a and miR-146b) in the innate immune response to S. typhimurium infection. To determine the role of miR-146 microRNAs in the response to S. typhimurium infection we used Illumina RNA sequencing to compare the mRNA expression profiles of control embryos versus embryos with knockdown of miR-146a and miR-146b. RNA sequencing analysis of miR-146 knockdown embryos showed no major effects on pro-inflammatory gene expression or on the expression of transcriptional regulators and signal transduction components of the immune response. In contrast, apoliprotein-mediated lipid transport emerged as an infection-inducible pathway under miR-146 knockdown conditions, suggesting a function of miR-146 in regulating lipid metabolism during inflammation. Embryos were injected at the one cell stage with a combination of two morpholinos targeting miR-146a and miR-146b, or with the standard control morpholino from GeneTools. Subsequently, at 28 hours post fertilzation (hpf) they were infected by injecting 200-250 colony forming units of S. typhimurium strain SL1027 into the caudal vein, or mock-injected with PBS. RNA was isolated at 8 hours post injection (hpi) for Illumina RNAseq analysis. Two independent experiments were performed for RNAseq analysis of biological duplicates.
2013-09-16 | E-GEOD-45209 | biostudies-arrayexpress
Project description:Pseudomonas aeruginosa is an opportunistic pathogen that requires iron for growth and virulence, yet this nutrient is sequestered by the innate immune system during infection. When iron is limiting, P. aeruginosa expresses the PrrF1 and PrrF2 small regulatory RNAs (sRNAs), which post-transcriptionally repress expression of non-essential iron-containing proteins thus sparing this nutrient for more critical processes.The genes for the PrrF1 and PrrF2 sRNAs are arranged in tandem on the chromosome, allowing for the transcription of a longer heme-responsive sRNA, termed PrrH. While the functions of PrrF1 and PrrF2 have been studied extensively, the role of PrrH in P. aeruginosa physiology and virulence is not well understood. In this study, we performed transcriptomic and proteomic studies to identify the PrrH regulon.
2023-08-11 | PXD040948 | Pride
Project description:Background: Neuronal and glial differentiation in the murine hypothalamus is not complete at birth, but continues over the first two weeks postnatally. Nutritional status and Leptin deficiency can influence the maturation of neuronal projections and glial patterns, and hypothalamic gliosis occurs in mouse models of obesity. Gnasxl constitutes an alternative transcript of the genomically imprinted Gnas locus and encodes a variant of the signalling protein Gαs, termed XLαs, which is expressed in defined areas of the hypothalamus. Gnasxl-deficient mice show postnatal growth retardation and undernutrition, while surviving adults remain lean and hypermetabolic with increased sympathetic nervous system (SNS) activity. Effects of this knock-out on the hypothalamic neural network have not yet been investigated. Results: RNAseq analysis for gene expression changes in hypothalami of Gnasxl-deficient mice indicated Glial fibrillary acid protein (Gfap) expression to be significantly down-regulated in adult samples. Histological analysis confirmed a reduction in Gfap-positive glial cell numbers specifically in the hypothalamus. This reduction was observed in adult tissue samples, whereas no difference was found in hypothalami of postnatal stages, indicating an adaptation in adult Gnasxl-deficient mice to their earlier growth phenotype and hypermetabolism. Especially noticeable was a loss of many Gfap-positive α-tanycytes and their processes, which form part of the ependymal layer that lines the medial and dorsal regions of the 3rd ventricle, while β-tanycytes along the median eminence (ME) and infundibular recesses appeared unaffected. This was accompanied by local reductions in Vimentin and Nestin expression. Hypothalamic RNA levels of glial solute transporters were, unchanged, indicating a potential compensatory up-regulation in the remaining astrocytes and tanycytes. Conclusion: Gnasxl deficiency does not directly affect glial development in the hypothalamus, since it is expressed in neurons, and Gfap-positive astrocytes and tanycytes appear normal during early postnatal stages. The loss of Gfap-expressing cells in adult hypothalami appears to be a consequence of the postnatal undernutrition, hypoglycaemia and continued hypermetabolism and leanness of Gnasxl-deficient mice, which contrasts with gliosis observed in obese mouse models. Since α-tanycytes also function as adult neural progenitor cells, these findings might indicate further developmental abnormalities in hypothalamic formations of Gnasxl-deficient mice, potentially including neuronal composition and projections. 6 wildtype and 6 Gnasxlm+/p- RNA isolates were used, which were pooled in pairs in equal concentrations prior to rRNA removal using the RiboMinus kit (Life Technologies)
2016-04-14 | E-GEOD-75878 | biostudies-arrayexpress
Project description:It is well known that bacteria often exist in naturally formed multispecies biofilms. Within these biofilms, interspecies interactions seem to play an important role in ecological processes. Little is known about the effects of interspecies interactions on gene expression in these multispecies biofilms. This study presents a comparative gene expression analysis of the Xanthomonas retroflexus transcriptome when grown in a single-species biofilm and in dual- and four-species consortia with Stenotrophomonas rhizophila, Microbacterium oxydans and Paenibacillus amylolyticus. The results revealed complex interdependent interaction patterns in the multispecies biofilms. Many of the regulated functions are related to interactions with the external environment and suggest a high phenotypic plasticity in response to coexistence with other species. Furthermore, the changed expression of genes involved in aromatic and branched chain amino acid biosynthesis suggests nutrient cross feeding as an contribution factor for the observed synergistic biofilm production when these four species coexists in a biofilm. X. retroflexus was cultivated in three replicates of single-species biofilm and combined with S. rhizophila, M. oxydans and P. amylolyticus in dual-species biofilms with three respective replicates. At last, we combined all four species in a multispecies biofilm with five replicates and conducted a RNA seq based comparative gene expression study utilizing the Illumina sequencing technology. Please note that the 'prodigal_all_new.txt' contains gene names (which are listed in the matrix_sum.txt) and their position in the genomes, which are included in the file 'all_contigs_500.fasta'.
2016-07-22 | E-GEOD-80267 | biostudies-arrayexpress