Transcritptome of a reeS deletion mutant of Clostridium perfringens during exponential phase growth.
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ABSTRACT: ReeS, previously named as CPE1512, was originally annotated as the only hybrid sensor histidine kinase/response regulator in Clostridium perfringens. Further evidence suggests that ReeS is more likely to function as an orphan sensor histidine kinase. A reeS deletion mutant was constructed and the transcriptome analysed using microarrays. Total RNA was isolated from the reeS mutant and the wild-type control cells during exponential phase growth. Gene expression levels were compared between the reeS mutant and wild-type strain 13
Project description:The MalNO is a putative two-component signal transduction system, previously known as the VirJI sytem. MalO is the putative cognate response regulator of the MalN sensor histidine kinase. Based on previous evidence that suggested the plc gene, encoding ?-toxin, was upregulated during stationary phase in the malO mutant, microarrays were used to analyse the transcriptome of a malO mutant during stationary phase growth. Total RNA was isolated from stationary phase cells of the malO mutant and the wild-type control. Gene expression levels were compared between the malO mutant and wild-type strain 13
Project description:RevR is a putative orphan response regulator with a high degree of similarity to YycF from Bacilus subtilis and PhoB from Clostridium kluyveri. A revR deletion mutant of C. perfringens strain 13 was generated and the transcriptome analysed using microarrays. Total RNA was isolated from exponentially growing cells from the revR mutant and the wild-type control. Gene expression levels were compared between the revR mutant and wild-type strain 13
Project description:Gene expression profiling of biopsied human lymph node (LN) tissue comparing each patient sample against mobilised peripheral blood stem cells (PBSC), the reference channel Evaluate whether gene expression microarray can diagnose lymph node biopsies as reactive or as one of three main types of lymphoma: classical Hodgkin’s lymphoma (cHL), diffuse large B cell lymphoma (DLBCL) or follicular lymphoma (FL). Two condition experiment, LN vs mobilised PBSC, 116 cases assayed, 1 replicate per array
Project description:Group A streptococci (GAS) may engage different sets of virulence strategies, depending on the site of infection and host context. We previously isolated 2 phenotypic variants of a globally disseminated M1T1 GAS clone: a virulent wild-type (WT) strain, characterized by a SpeB(+)/SpeA(-)/Sda1(low) phenotype, and a hypervirulent animal-passaged (AP) strain, better adapted to survive in vivo, with a SpeB(-)/SpeA(+)/Sda1(high) phenotype. This AP strain arises in vivo due to the selection of bacteria with mutations in covS, the sensor part of a key 2-component regulatory system, CovR/S. To determine whether covS mutations explain the hypervirulence of the AP strain, we deleted covS from WT bacteria (DeltaCovS) and were able to simulate the hypervirulence and gene expression phenotype of naturally selected AP bacteria. Correction of the covS mutation in AP bacteria reverted them back to the WT phenotype. Our data confirm that covS plays a direct role in regulating GAS virulence. A dye-swapped cyclic design was used in this study in order that each strain could be compared across all samples in silico. For each strain treated, 2 biological replicates were each analysed in dye-swapped technical replicates, giving a total of n=10 peplicates for each strain.
Project description:We identified a mutation that is a frameshift mutation in a mononucleotide run of eight consecutive T's in the coding region of the gene SSY1, which encodes a key component of a plasma-membrane sensor of extracellular amino acids.We introduced it into the S288c background and examined the effect on gene expression. Keywords: Total gene expression analysis S288C wt, S288C ssy1-t9 and S288C ssy1-ko were compared
Project description:Chickens were kept under a regimen of 12 hours of light and 12 hours of dark for 7 days. At LD2, 2 hours into the light cycle on the 8th day, 3 chickens were sacrificed by decapitation and their retinas dissected and pooled. Similarly, at LD18, 6 hours into the dark cycle on the 8th day, retinas were harvested from 3 chickens. Total RNA was extracted from each set of retinas using Trizol Reagent (Invitrogen). The total RNA samples were amplified to produce aRNA using the Message Amp Kit (Ambion). Randomly primed fluorescent probes were produced from the aRNA samples using a Genisphere 3DNA Array 900MPX expression array detection kit. The fluorescent dye on the probe derived from the experimental aRNA (LD2) was Cy5 while the dye on the control probe (LD18) was Cy3. Hybridizations and washes were as suggested by Genisphere. Labeled arrays were scanned in an Affymetrix 428 array scanner. The images obtained were subsequently analyzed by GenePixPro software (Axon Instruments). The GenePix results (.gpr) file was further analyzed by GeneSpring 5 (Silicon Genetics) which applied intensity dependent LOWESS normalization to the results and calculated normalized Cy5 to Cy3 ratios. This GEO Series was created by the GEO staff as part of a cleanup effort to ensure that all GEO Samples are included within a Series entry.
Project description:Leptospirosis is a globally significant zoonotic disease caused by Leptospira spp. Iron is essential for growth of most bacterial species. Since availability of iron is low in the host, pathogens have evolved complex iron acquisition mechanisms to survive and establish infection. Virulence genes in some bacteria have been shown to be iron-regulated. In many bacteria, expression of iron-uptake and storage proteins is regulated by Fur. L. interrogans encodes four predicted Fur homologs; we have constructed a mutant in one of these, la1857. We conducted microarray analysis to identify differentially expressed genes in L. interrogans serovar Manilae grown under low iron compared with normal iron conditions found in EMJH medium. We also compared the transcriptional profile of the la1857 mutant versus wild-type Manilae under normal and low iron conditions. Analysis used RNA derived from L. interrogans serovar Manilae grown under low iron (EMJH medium + 40 µM 2,2-dipyridyl) and normal iron as experimental and control samples, respectively. We have a serovar Manilae mutant in la1857, one of four predicted fur homologs. The mutant was also grown under low iron and normal iron conditions and compared with wild-type Manilae grown under low and normal iron conditions respectively. Three independent RNA samples (biological replicates) from parent and mutant strains grown with or without 2,2-dipyridyl were compared in a loop design resulting in 12 arrays. The orientation of Cy3 to Cy5 labeling was the same for replicates 1 and 3, while replicate 2 was a dye swap. Direct comparisons were made between arrays of experimental and control samples using raw data pulled from two different channels for data analysis. Data from wild-type Manilae grown under low iron versus normal iron and mutant versus wild-type under normal iron conditions is reported in the manuscript.
Project description:L. interrogans, a causative agent of leptospirosis, can survive in the environment for lengthy periods of time in between infection of mammalian hosts. In order to identify genes involved in survival in the early spirochetemic phase of infection, we performed a transcriptional analysis of L. interrogans serovar Copenhageni upon exposure to serum in comparison with EMJH medium. Analysis used RNA derived from serum- and EMJH-treated L. interrogans serovar Copenhageni as experimental and control samples, respectively. The samples were composed of 3 biological replicates with dye swap for each replicate, resulting in 6 arrays. Direct comparisons were made between arrays of experimental and control samples using raw data pulled from two different channels for data analysis.
Project description:Herpes simplex virus mutants lacking the vhs gene are severely attenuated in animal models of pathogenesis and exhibit reduced growth in primary cell culture. As a result of these properties vhs-deleted virus have been proposed as live-attenuated viruses. Despite these findings and their implications for vacccines, the mechanisms by which vhs promotes infection in cell culture and in vivo are not understood. In this study we demonstrate that vhs-deficent viruses replicate to reduced levels in interferon(IFN)- primed cells. Furthermore, vhs-defective viruses induce increased levels of IFN? and IFN?-stimulated genes, and increased levels of eIF2? phosphorylation in infected cells. In addition, we demonstrate a generalized over-expression of viral RNAs following infection with a vhs-deficient virus. This suggests increased expression of IFN pathway inducing double stranded RNA, a potent pathogen-associated molecular pattern (PAMP). Together these data show that vhs likely functions to reduce innate immune responses and thereby acts as critical determinant of viral pathogenesis. Keywords: time course, genetic modification Time course (1,3,6,9 & 12h) of HSV infected mouse embryo fibroblasts. Wild type (KOS) virus is co-hybridized with vhs null virus (NHB). Each time-point is hybridized in quadruplicate.
Project description:Gene expression profile of Human hepatocellular carcinoma were investigated with spotted cDNA microarray technology. Tumor and non-tumorous region used this experiment were hybridization with normal liver total RNA in same cDNA chip, respectivly. All tests were accompanied with dye-swap normalization.