Transcription profiling of rat colon after dietary treatment with fructo oligosaccharides
Ontology highlight
ABSTRACT:
ORGANISM(S): Rattus norvegicus
SUBMITTER: Wendy Rodenburg
PROVIDER: E-GEOD-5943 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:To increase our knowledge of the effects of Fructo oligosaccharides (FOS) on Salmonella infection in fats, a controlle rat infection study was performed. Two groups of 12 rats were adapted for 14 days to a cellulose diet and one group of 12 rats to a FOS diet. One cellulose-fed group and the FOS-fed group were infected with Salmonella. Two days post infection mRNA was collected from the mucosa of the colon and changes in gene expression were assessed using an Agilent rat whole genome microarray (G4131A Agilent Technologies). Results indicate that Salmonella affects colonic mucosal gene expression, which is further enhanded by dietary FOS. Experiment Overall Design: In the present study, large-scale gene expression analysis was performed to reveal whether Salmonella induced changes of colonic mucosal gene expression in rats. Furthermore, we compared the colonic gene expression changes of infected rats fed a diet supplemented with Fructo oligosaccharides (FOS) or cellulose as control. Two groups of Wistar rats (n=12) were adapted for 14 days to a cellulose diet and one group (n=12) to a FOS diet. One cellulose-fed group and the FOS-fed group were infected with Salmonella. RNA was isolated from colonic mucosal scrapings. mRNA samples of 12 rats per group were pooled. Each group-sample was hybridised in duplicate on Agilent rat whole genome microarrays containing 44290 60-mer spots.
2008-06-15 | E-GEOD-7472 | biostudies-arrayexpress
Project description:Due to its aquatic saprophytic lifestyle, the fungus Blastocladiella emersonii seems to be adapted to low aerated environments and thus can be an interesting model of study of the hypoxic stress response. Iron deprivation, a hypoxia-mimicking stimulus due to HIF-1 stabilization, and geldanamycin, that causes HIF-1 depletion by HSP90 inhibition, are helpful parameters to find an evidence of an oxygen-dependent regulatory mechanism in B. emersonii similar to the metazoan HIF-1 pathway. Direct transcript comparison between cells grown under normoxic conditions (70%sat. O2 in air) and cells submitted to oxygen deprivation (direct and gradual) and iron (II) deprivation. It was also compared transcripts of cells submitted to direct 1-hour hypoxia (1%sat. O2) with cells treated with geldanamycin for 1 hour, followed to 1-hour hypoxia (1%sat. O2). There are at least 3 biological replicates (independent harvest) and 2 technical replicates of each array (L - left and R - right).
2010-06-24 | E-GEOD-17524 | biostudies-arrayexpress
Project description:Blastocladiella emersonii life cycle presents a number of drastic biochemical and morphological changes, mainly during two cell differentiation stages: the germination and the sporulation. To investigate the transcriptional changes taking place during the sporulation phase, which culminates with the production of the zoospores, motile cells responsible for the dispersal of the fungus, microarray experiments were performed. Transcription comparisons between cell at the begining of the sporulation phase (zero min.) and at different time points throughout zoospore differentiation were performed in order to associate the gene expression profile with the morphologial changes which culminate with zoospore differentiation. Microarray experiments along the sporulation phase were also realized in the presence of 1% glucose, once such carbohydrate is able to block zoospore differentiation. The results obtained from both sets of experiments were compared in order to understand the glucose effect on sporulation. There are at least 3 biological replicates (independent harvest) and 2 technical replicates of each array (L - left and R - right).
2009-10-27 | E-GEOD-18718 | biostudies-arrayexpress
Project description:Background: Xylella fastidiosa, a Gram-negative fastidious bacterium, grows exclusively in the xylem of several plants, causing diseases such as citrus variegated chlorosis. As the xylem sap contains low concentrations of amino acids and other compounds, X. fastidiosa needs to cope with nitrogen limitation in its natural habitat. Results: In this work, we performed a whole-genome microarray analysis of the X. fastidiosa nitrogen starvation response. A time-course experiment (2, 8 and 12 hours) revealed many differentially expressed genes under nitrogen starvation, such as genes related to transport, nitrogen assimilation, amino acid biosynthesis, transcriptional regulation, and many genes encoding hypothetical proteins. In addition, a decrease in the expression levels of many genes involved in carbon metabolism and energy generation pathways was also observed. Comparison of gene expression profiles between the wild type strain and the rpoN null mutant allowed the identification of genes induced by nitrogen starvation in a ?54-dependent manner. A more complete picture of the ?54 regulon was achieved by combining the transcriptome data with an in silico search for potential ?54-dependent promoters, using a position weight matrix approach. One of these ?54-predicted binding sites, located upstream of the glnA gene (encoding a glutamine synthetase), was validated by primer extension assays, confirming that this gene has a ?54-dependent promoter and contains a predicted NtrC binding site. Conclusions: Together, these results show that nitrogen starvation causes intense changes in the X. fastidiosa transcriptome and some of these differentially expressed genes belong to the ?54 regulon. For time-course studies, cells cultivated at late-exponential phase in PWG medium were used to inoculate a culture in 100 ml XDM2 medium to an optical density at 600 nm (OD600 nm) of 0.1. Cells were grown during 12 days in the XDM2 medium (mid-log phase) and harvested by centrifugation. Then, the culture was divided into two 6 portions and cells were washed with XDM2 medium (zero time) or XDM2 medium lacking all nitrogen sources (XDM0), respectively. The cultivation was continued for 2h, 8h and 12h in XDM0 to establish nitrogen starvation conditions. For each time point, cells in a 25-ml culture were collected by centrifugation and rapidly frozen in dry ice, until RNA isolation. Three RNA samples isolated from independently grown cultures of the cells at each starvation period (2h, 8h and 12h) were examined, and each preparation was subjected to microarray analysis. As the genes were spotted at least in duplicate, we obtained six replicates for each gene from three independent data sets per gene per starvation period. Comparison of gene expression profiles between the wild type strain and the rpoN null mutant allowed the identification of genes induced by nitrogen starvation in a ?54-dependent manner. To determine the effect of rpoN inactivation on gene expression after nitrogen starvation, the transcriptomes of the wild type and the rpoN strains were compared using DNA microarrays, with both strains grown on XDM2 medium and submitted to nitrogen starvation (XDM0) during 2 hours. Three RNA samples isolated from independently grown cultures of the cells were examined. Due to the platform design, each microarray slide was divided into "LEFT" and "RIGHT", allowing the probing of two technical replicates per slide.
2010-12-21 | E-GEOD-21647 | biostudies-arrayexpress
Project description:The phytopathogen Xylella fastidiosa produces two classes of pili, long type IV pili and short type I pili, which are involved in motility and adhesion. In this work, we have investigated the role of Ï54 factor and its involvement in the regulation of fimbrial biogenesis in X. fastidiosa. An rpoN null mutant was constructed from citrus strain J1a12, and analyses of global gene expression profile by microarrays comparing the wild type and rpoN mutant strains showed that few genes exhibited differential expression. At least one gene, pilA1 (XF2542), which encodes the structural pilin protein of type IV fimbriae, showed decreased expression in the rpoN mutant whereas an operon encoding proteins of type I fimbriae were twofold more expressed in the mutant. Quantitative real time RT-PCR (qRT-PCR) analysis confirmed that pilA1 transcript was significantly reduced in the rpoN mutant. The transcriptional start site of pilA1 was determined by primer extension, and a canonical Ï54-dependent promoter was found upstream of the start site. Genome sequence analysis of X. fastidiosa revealed five paralogues of pilA, but microarray and qRT-PCR data demonstrated that only the pilA1 transcript was significantly affected in the rpoN mutant. The rpoN mutant made more biofilm than the wild type strain and presented a cell-cell aggregative phenotype. These results indicate that Ï54 regulates biofilm formation, probably via differential regulation of genes involved in type IV and type I fimbrial biogenesis. Direct comparison between wild type strain J1a12 and mutant strain rpoN-.
2010-06-25 | E-GEOD-8097 | biostudies-arrayexpress
Project description:The global transcriptional response of the phytopathogenic bacterium X. fastidiosa to a sudden increase in salinity and osmolarity of the medium was investigated using DNA microarrays. Time-course experiments were carried out by exposing bacterial cells to high salinity (250 mM NaCl) and high osmolarity (300 mM sucrose) conditions revealing 142 upregulated genes under both stresses, including pathogenicity related genes, genes encoding transcriptional regulators, as well as genes related to DNA metabolism and mobile genetic elements. In addition, 38 genes were downregulated under both conditions, most of them related to ribosomal and heat shock proteins. A total of 192 genes were upregulated exclusively in the presence of NaCl, including genes encoding transporters, genes involved in oxidative-stress response and genes related to cell structure. A smaller number of genes (44 genes) were induced only in the presence of sucrose, most of them encoding hypothetical and conserved hypothetical proteins. Interestingly, 57% of the genes differentially expressed under both stress conditions have no putative function assigned, emphasizing the importance of high-throughput experiments to start the characterization of these genes in X. fastidiosa. Keywords: stress response, osmotic and salt stress Direct comparison between osmotic or salt stress condition and control (29oC) condition. Some hybridizations are dye-swaped. There are at least 3 biological replicates (independent harvest) and 2 technical replicates of each array (L - left and R - right).
2014-05-25 | E-GEOD-7126 | biostudies-arrayexpress
Project description:The study comprises various components: We aim to screen out different gene expression profile in acute rejection on the kidney. We aim to screen out different gene expression profile in acute tubular necrosis on the kidney. We aim to screen out different gene expression profile in borderline change on the kidney. We aim to screen out different gene expression profile in non-rejection on the kidney. We aim to screen out different gene expression profile in presumed rejection on the kidney. We aim to screen out different gene expression profile in renal recipients with stable function. Results from the various study components can help to diagnose renal allograft dysfunction with different causes by distinct gene expression profile. Keywords: acute rejection, acute tubular necrosis, borderline change, non-rejection, presumed rejection, renal recipients with stable function, Samples GSM456771-GSM456800: This study has been accomplished with 15 patients of acute rejection on the kidney.Technical replicates: 2 replicates(except AR10 and AR13) Samples GSM456801-GSM456810: This study has been accomplished with 5 patients of acute tubular necrosis on the kidney. Technical replicates: 2 replicates(except ATN4) Samples GSM456811-GSM456831: This study has been accomplished with 11 patients of borderline change on the kidney.Tecnical replicates:2 replicates(except BL8 and BL11) Samples GSM456833-GSM456850: This study has been accomplished with 9 patients of non-rejection on the kidney.Technical replicates: 2 replicates Samples GSM456851-GSM456864: This study has been accomplished with 7 patients of presumed rejection on the kidney.Technical replicates: 2 replicates Samples GSM456865-GSM456894: This study has been accomplished with 15 patients of renal recipients with stable function.Technical replicates: 2 replicates
2010-06-25 | E-GEOD-19130 | biostudies-arrayexpress
Project description:Xylella fastidiosa is the etiologic agent of a wide range of plant diseases including citrus variegated chlorosis (CVC), a major threat to the Brazilian citrus industry. Genome sequences of several strains of this phytopathogen are accessible, enabling large-scale functional studies. Transcript levels in different iron availabilities were assessed with DNA microarrays representing 2608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c. When treated with the iron chelator 2,2-dipyridyl, 193 CDS were considered as up-regulated and 216 as down-regulated. In the presence of 100uM of ferric pyrophosphate, 218 and 256 CDS were considered as up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription - quantitative PCR that showed a Pearson correlation of 0.77 with array results. The CDS differentially expressed upon the iron concentration shift participate in diverse cellular functions. Many CDS involved with regulatory functions, pathogenicity and cell structure, were modulated in both conditions tested suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to pili/fimbriae functions. We also investigated the contribution of the ferric uptake regulator Fur to the iron regulon of X. fastidiosa. The promoter regions of strain 9a5c genome were screened for putative Fur boxes and candidates were analyzed by electrophoretic mobility shift assays. Taken together, our data support the hypothesis that Fur is not solely responsible for the modulation of the iron regulon of X. fastidiosa and present novel evidence for iron regulation of pathogenicity determinants. Keywords: stress response; response to iron-depleted condition Direct comparison between low iron content (200uM 2,2-dipyridyl) and control condition. Hybridizations are dye-swaped. There are 2 biological replicates (independent harvest) and 2 technical replicates of each array (L - left and R - right).
2007-08-31 | E-GEOD-5888 | biostudies-arrayexpress
Project description:Xylella fastidiosa is the etiologic agent of a wide range of plant diseases including citrus variegated chlorosis (CVC), a major threat to the Brazilian citrus industry. Genome sequences of several strains of this phytopathogen are accessible, enabling large-scale functional studies. Transcript levels in different iron availabilities were assessed with DNA microarrays representing 2608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c. When treated with the iron chelator 2,2-dipyridyl, 193 CDS were considered as up-regulated and 216 as down-regulated. In the presence of 100uM of ferric pyrophosphate, 218 and 256 CDS were considered as up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription - quantitative PCR that showed a Pearson correlation of 0.77 with array results. The CDS differentially expressed upon the iron concentration shift participate in diverse cellular functions. Many CDS involved with regulatory functions, pathogenicity and cell structure, were modulated in both conditions tested suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to pili/fimbriae functions. We also investigated the contribution of the ferric uptake regulator Fur to the iron regulon of X. fastidiosa. The promoter regions of strain 9a5c genome were screened for putative Fur boxes and candidates were analyzed by electrophoretic mobility shift assays. Taken together, our data support the hypothesis that Fur is not solely responsible for the modulation of the iron regulon of X. fastidiosa and present novel evidence for iron regulation of pathogenicity determinants. Direct comparison between high iron content (100uM ferric pyrophosphate) and control condition. Hybridizations are dye-swaped. There are 2 biological replicates (independent harvest) and 2 technical replicates of each array (L - left and R - right).
2007-09-01 | E-GEOD-5886 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE4968: Sugarcane transcriptome - ABA treatment GSE4971: Sugarcane transcriptome - Drought response GSE14730: Expression profile in internodes 1, 5 and 9 from high and low brix plants for sucrose content GSE14731: Expression profile between internodes 1 and 9 from high and low brix plants for sucrose content Refer to individual Series
2010-06-30 | E-GEOD-14732 | biostudies-arrayexpress