Project description:The existence of two separate lineages of Escherichia coli O157:H7 has previously been reported, and research indicates that one of these lineages (lineage I) might be more pathogenic towards human hosts. We have previously shown that the more pathogenic lineage expresses higher levels of Shiga toxin 2 (Stx2) than the non-pathogenic lineage II. To evaluate why lineage 2 isolates do not express appreciable levels of toxin, two lineage 2 isolates (FRIK966 and FRIK2000) were chosen as representatives of lineage 2 and whole genome microarrays were performed using Agilent microarrays using the E. coli O157:H7 EDL933 lineage I clinical type isolate as a reference. Microarray results were utilized to evaluate what genes and pathways might be missing or differentially expressed. Quantitative RT-PCR was utilized to validate the microarray data. Based upon the transcriptome of Escherichia coli O157:H7 EDL933 an oligonucleotide microarray, made up of 60 mers was designed. A total of 4873 genes in an 8 x 15K Agilent microarray design. Designed using a custom script, specifications for gene specific oligos were based upon various design characteristics such as temperature of melting, 3’ location, specificity, lack of repeat nucleotides, etc. (Charbonnier et al., 2005). Arrays were manufactured using Agilent Sure-print technology. Each array consisted of duplicate elements for each gene randomly distributed with Agilent control elements included. All procedures were performed according to respective manufacturer protocols. Lineage I and lineage II strains were grown overnight as described, a total of 10e7 cells were washed twice in fresh media, normalized based upon optical density, inoculated into fresh media, incubated at 37oC shaking 120 x g for 3 hours and then suspended in RNAprotect bacteria reagent (Qiagen Inc., Valencia, CA.). Total RNA was extracted using RNeasy Bacteria Mini Kit (Qiagen Inc., Valencia, CA.) and trace amounts of DNA were removed using RNase-Free DNase Set (Qiagen Inc., Valencia, CA.). RNA was quantified using Nanodrop system (NanoDrop Technologies, Wilmington, DE) and quality confirmed by electrophoresis on a Bio-rad Experion system (BioRad XXX). For each sample, 10 ug of RNA were labeled with either CyDye3-dCTP or CyDye5-dCTP (Perkin Elmer) using the LabelStar kit (Qiagen Inc., Valencia, CA.) and Random nonamers (Integrated DNA Technologies ). Labeled cDNA were hybridized to the microarray using Agilent Hi-RPM hybridization solution in an Agilent Hybridization chamber (Agilent.). A total of 8 arrays, each with duplicate elements for each gene, alternating dye swap for each replicate (4 biological replicates), were analyzed to obtain genes that were consistently and differentially regulated in comparison to EDL933, while limiting false discover rate (FDR) below a stringent 5% (Benjamini and Hochberg, 1995).

Project description:Anopheles gambiae mosquitoes exhibit an endophilic, nocturnal blood feeding behavior. Despite the importance of light as a regulator of malaria transmission, our knowledge on the molecular interactions between environmental cues, the circadian oscillators and the host seeking and feeding systems of the Anopheles mosquitoes is limited. In the present study, we show that the blood feeding behavior of mosquitoes is under circadian control and can be modulated by light pulses, both in a clock dependent and in an independent manner. Short light pulses (~2-5 min) in the dark phase can inhibit the blood-feeding propensity of mosquitoes momentarily in a clock independent manner, while longer durations of light stimulation (~1-2 h) can induce a phase advance in blood-feeding propensity in a clock dependent manner. The temporary feeding inhibition after short light pulses may reflect a masking effect of light, an unknown mechanism which is known to superimpose on the true circadian regulation. Nonetheless, the shorter light pulses resulted in the differential regulation of a variety of genes including those implicated in the circadian control, suggesting that light induced masking effects also involve clock components. Light pulses (both short and longer) also regulated genes implicated in feeding as well as different physiological processes like metabolism, transport, immunity and protease digestions. RNAi-mediated gene silencing assays of the light pulse regulated circadian factors timeless, cryptochrome and three takeout homologues significantly up-regulated the mosquito's blood-feeding propensity. In contrast, gene silencing of light pulse regulated olfactory factors down-regulated the mosquito's propensity to Our study suggests that the mosquitoâs feeding behavior is under circadian control. Long and short light pulses can induce inhibition of blood-feeding through circadian and unknown mechanisms, respectively, that involve chemosensory factors. A series of assays were performed to assess transcriptomic changes in mosquitoes upon light stimulation and blood feeding in order to assess relationships between photic stimulation and modulation of feeding behavior.

Project description:Background: The mosquito Anopheles gambiae is a major vector of human malaria. Increasing evidence indicates that blood cells (hemocytes) comprise an essential arm of the mosquito innate immune response against both bacteria and malaria parasites. To further characterize the role of hemocytes in mosquito immunity, we undertook the first genome-wide transcriptomic analyses of adult female An. gambiae hemocytes following infection by two species of bacteria and a malaria parasite. Results: We identified 4047 genes expressed in hemocytes, using An. gambiae genome-wide microarrays. While 279 transcripts were significantly enriched in hemocytes relative to whole adult female mosquitoes, 959 transcripts exhibited immune challenge-related regulation. The global transcriptomic responses of hemocytes to challenge with different species of bacteria and/or different stages of malaria parasite infection revealed discrete, minimally overlapping, pathogen-specific signatures of infection-responsive gene expression; 105 of these represented putative immunity-related genes including anti-Plasmodium factors. Of particular interest was the specific co-regulation of various members of the Imd and JNK immune signaling pathways during malaria parasite invasion of the mosquito midgut epithelium. Conclusion: Our genome-wide transcriptomic analysis of adult mosquito hemocytes reveals pathogen-specific signatures of gene regulation and identifies several novel candidate genes for future functional studies. In order to identify hemocyte-specific and immune-responsive transcripts, we first compared transcripts expressed in hemocytes from one day old sugar-fed mosquitoes to transcripts detected in whole mosquitoes of the same age and feeding status. This resulted in identification of the hemocyte-enriched transcriptome. We then compared hemocytes from 1 day old mosquitoes, 1 hour after immune challenge with heat-killed Escherichia coli or Micrococcus luteus, to control female mosquitoes injected with sterile PBS to determine the bacteria challenge responsive transcriptomes. We used heat-killed bacteria in these assays, because our primary interest was in identifying the bacterial responsive transcriptome and to avoid the potentially confounding effects of altered gene expression due to the lethal effects of a systemic infection associated with injection of living bacteria. Lastly, we compared hemocytes from mosquitoes at 24 hours and 19 days after ingestion of a blood meal infected with Plasmodium berghei to mosquitoes of the same age fed a non-infected blood meal to determine the ookinete and sporozoite infection responsive transcriptomes, respectively. This design resulted in a total of five experimental treatments. The following samples are not included in this submission: Hemo E coli vs. hemo unchallenged A Hemo E coli vs. hemo unchallenged B Hemo m luteus vs. hemo unchallenged A Hemo m luteus vs. hemo unchallenged B

Project description:This series represents the effects of OVA, tg-IL-13, and direct effects of IL-13 on airway epithelial cells. Experiment Design: Type of experiment: comparison of three related murine models of asthma, 1) Ova model, 2) tg-IL-13 model, 3) IL-13/Epi model. Two control groups were used: PBS challenged mice to control for the effects of OVA and tg-IL-13+ and STAT6-/- mice as controls for tg-IL-13 and IL-13/Epi mice. Measurements were made in each model in two types of tissue samples, whole lung and tracheal perfusate. Experimental factors: Allergen vs sham challenge, natural STAT6 expression vs transgenic expression and no expression. The number of hybridizations performed in the experiment: 50 (25 whole lung and 25 tracheal perfusate). The type of reference used for the hybridizations, if any: Pooled reference from lung (whole lung or tracheal perfusate) from untreated wildtype mice. Hybridization design: two-color hybridizations with reference design. Each individual sample was hybridized to a separate array. Quality control steps taken: 5 experimental replicates per group. RNA integrity assessed by Agilent Bioanalyzer. Arrays with low signals, high background, or high spatial variation rejected and corresponding samples reanalyzed. URL of any supplemental websites or database accession numbers:GEO (http://www.ncbi.nlm.nih.gov/geo, accession number GSE1438). ********** Samples used, extract preparation and labeling: The origin of the biological sample: homogenized whole lung from mouse and perfusate of mouse trachea. Manipulation of biological samples and protocols used: Whole lungs mechanically homogenized in 7.0 ml Trizol reagent (Invitrogen) for total RNA collection. Tracheas perfused with lysis buffer (Qiagen Rneasy kit) for total RNA collection. Protocol for preparing the hybridization extract and labeling: Preparation of aminoallyl-UTP labeled whole lung cDNA was performed as described [1]. Total RNA from tracheal perfusate (1.0 - 1.5 g per sample) was amplified and labeled with aminoallyl-dUTP using the MessageAmp aRNA kit (Ambion). Labeled cRNAs were coupled to Cy3 or Cy5 dyes (CyScribe, Amersham Biosciences) and purified as described [1]. Labeling protocol(s): Coupled to Cy3 or Cy5.External controls (spikes): none. ********** Hybridization procedures and parameters: Hybridizations were performed as described [1] except Ambion SlideHyb Glass Array Hybridization Buffer #1 (neat concentration) was used as hybridization buffer and hybridizations were carried out for 40 h at 55 Â°C. Following hybridization, arrays were washed in 1X SSC with 0.03% SDS (wash 1), 0.2X SSC (wash 2), and 0.05X SSC (wash 3) for five minutes for each wash. ********** Measurement data and specifications: Arrays were scanned using an Axon Genepix 4000B scanner and GenePix Pro Analysis 5.0 software; laser power 100%, 10 micron resolution, PMT optimized for each array. Data from GPR files are available from GEO (http://www.ncbi.nlm.nih.gov/geo, accession number GSE1438).The âprint-tip loessâ normalization was used to correct for within-array dye and spatial effects and single channel quantile normalization was used to facilitate comparison between arrays. No background subtraction was performed. We used functions in the library marrayNorm of the R / Bioconductor package to perform these normalizations. After normalization we determined the log2 ratio of experimental sample intensity to reference sample intensity for each probe on each array. ********** Array Design: General array design Array design name: UCSF 10Mm Mouse v.2 Oligo Array (GEO GPL1089) and UCSF Gladstone 18K Mouse v.2 Oligo Array (GPL1196) Platform type: spotted oligonucleotides (70mers) Surface and coating specification: aminosilane coated glass slides Physical dimensions of array support (e.g. of slide): 25 x 75 x 1.0 mm Number of features on the array: GPL1089: 19152, GPL1196: 18240 (including empty and duplicate features) For production protocol, see http://www.microarrays.org/pdfs/PrintingArrays.pdf Feature information is available from GEO (GSE1438). Reporters: synthetic single stranded oligonucleotides. Sequence and annotation information available from GEO (GPL1089 and GPL1196) Method of reporter preparation: synthesized by Operon. The spotting protocols used, including the array substrate, the spotting buffer, and any post-printing processing, including cross-linking: see http://www.microarrays.org/pdfs/PrintingArrays.pdfAny additional treatment performed prior to hybridization: none. ********** Reference: 1. Barczak A, Rodriguez MW, Hanspers K, Koth LL, Tai YC, et al. (2003) Spotted long oligonucleotide arrays for human gene expression analysis. Genome Res 13: 1775-1785. Keywords = IL-13 Keywords = Epithelial Keywords = differential gene expression Keywords = microarray

Project description:We have designed a zebrafish genomic microarray to identify DNA-protein interactions in the proximal promoter regions of over 11,000 zebrafish genes. Using these microarrays, together with chromatin immunoprecipitation with an antibody directed against tri-methylated lysine 4 of Histone H3, we demonstrate the feasibility of this method in zebrafish. This approach will allow investigators to determine the genomic binding locations of DNA interacting proteins during development and expedite the assembly of the genetic networks that regulate embryogenesis. Genomic array design Microarrays were designed as described below and manufactured by Agilent Technologies (www.agilent.com). Further information on design can be found at http://jura.wi.mit.edu/bioc/gbell/zfish_chip/. Selection of transcription start sites and identification of promoter sequences We interrogated 5 databases: Ensembl, VEGA, Refseq, ZGC full length clones and a database provided by Dr. Leonard Zon (Harvard Medical School, Boston, USA) in order to assemble an extensive list of zebrafish transcripts. The Zon lab database is a hand-curated database of zebrafish genes that have homologues in other species. We included all transcripts that appeared in the manually annotated databases (VEGA, Zon) and in the ZGC full length database. We also identified genes present in any 2 of the 5 databases and included those not already selected. The transcripts were mapped to the zebrafish genome (Zv4, June 2004) obtained from UCSC Bioinformatics (http://genome.ucsc.edu) and the transcription start site (TSS) for each transcript was determined. Transcripts with TSSs within 500bp were clustered into a transcriptional unit (TU) and promoter regions were identified relative to the most upstream TSS. This resulted in the identification of 13,413 TUs and corresponding promoter regions. Each promoter region was extracted and masked for repetitive sequence by RepeatMasker. If the promoter region contained a gap the upstream sequence was also masked. Information on the transcriptional units that were included in the final design can be found at http://jura.wi.mit.edu/bioc/gbell/zfish_chip/. Selection of oligonucleotides 60-mer oligonucleotide probes representing the region between 1.5kb upstream and 0.5kb downstream of the annotated TSS of each transcriptional unit were then designed. Although transcription factors and other DNA binding proteins are known to regulate genes from distances of greater than -1.5kb or + 0.5kb, much information can be gained from regions close to the TSS [45], and the H3K4Me3 mark studied in this paper is found at the most 5â end of a gene, close to the TSS. Selection of 60-mers for the microarrays was essentially as described in [14] using the Zv4 build of the zebrafish genome and a locally customized version of ArrayOligoSelector. 60-mers were chosen so that promoter regions contained approximately one probe every 250bp with a maximum distance between probes for each promoter region set at 600bp. In cases where only one probe could be designed for a particular TU these were not included in the final design. This process yielded 80,839 probes for 11,171 promoter regions We also incorporated several sets of control probes, both positive and negative. On each array there are 1090 probes designed against âgene desertâ regions, which are genomic regions that are unlikely to be bound by transcriptional regulators, and 270 probes designed against Arabidopsis thaliana genes, which are not present in the zebrafish genome (by BLAST). In addition, because our main motivation for making these microarrays is to identify mesodermally-regulated genes we included 7 genes expressed in mesoderm during gastrulation as positive controls (wnt11, flh, vent, msgn1, myod, fgf8, pcdh8). Probes designed against these promoters, which flank from 3-4kb around each TSS, are arrayed 2-4 times on each slide. Since these genes are expressed at gastrula stages to varying degrees, they also serve as a positive controls in this study. Finally there are 2256 controls added by Agilent and a variable number of blank spots. These probes were divided between two microarray slides each with 44,290 features. We refer to these two microarray slides as the âproximal promoter setâ. A proximal promoter set based on these designs as well as an expanded set of 9 slides which contain regions from â9kb to + 3kb relative to the TSS, are available by contacting Agilent (www.agilent.com) or by downloading the design files from http://jura.wi.mit.edu/bioc/gbell/zfish_chip/ for self-manufacture.

Project description:NOD mice (8- to 13-wk-old) were bred and maintained at the La Trobe University Central Animal House (Bundoora, Melbourne, Australia). All experiments were conducted in accordance with the Australian code of practice for the care and use of animals for scientific purposes (National Health and Medical Research Council 1997), after approval by the La Trobe University Animal Ethics committee (Melbourne, Australia). A total of 124 female mice were divided into three groups. The immunized group comprised 91 mice injected s.c. into the lower flanks with 200 micrograms of MOG35-55 peptide (MEVGWYRSPFSRVVHLYRNGK; Auspep) emulsified in CFA containing 4 mg/ml Mycobacterium tuberculosis (Difco). An i.v. injection of 350 ng of Bordetella pertussis toxin was administered both immediately thereafter and 48 h later. The 26 mice in the control group were injected with adjuvant and pertussis toxin only. The seven animals used for the baseline group (time, day 0) were naive, not injected mice. Except for the seven naive animals from the baseline group, nine animals (seven from the EAE and two from the control group) were sacrificed (at the same time of the day) at each of 13 time points after immunization, which are detailed as days 3, 5, 7, 9, 11, 12, 13, 14, 15, 16, 17, 18, and 19 postimmunization. Lymph nodes from the remaining four animals of the immunized and from the two control groups were dissected, immersed in RNAlater (Ambion), and frozen at 20C. Lymph nodes were removed from RNAlater and homogenized in TRIzol (Invitrogen Life Technologies) using an electric homogenizer. After resuspending the final RNA pellet in water, samples were repurified using the RNeasy kit (Qiagen). cDNA was synthesized from 15 micrograms of total RNA using Superscript II RT (Invitrogen Life Technologies) and a modified dNTP mix containing dUTP. Samples were hydrolyzed by adding 10 microliters of 0.1 N NaOH, neutralized with 25 microliters of 1 M HEPES, and precipitated with 3 M sodium acetate and ethanol. Resuspension in 0.05 M sodium bicarbonate was followed by 1 h incubation with either N-hydroxysuccinimide ester Cy3 or Cy5 fluorescent dyes (Amersham Biosciences). Probes were quenched by the addition of 4 M hydroxylamine and neutralized with 100 mM sodium acetate. Final probe cleanup was conducted using the QIA Quick PCR purification kit (Qiagen). We followed a common reference design in which each Cy3-labeled lymph node probe was combined with a Cy5-labeled probe derived from a pool of RNA. Hybridization onto glass slides containing 18,240 spotted 60- to 70-mer oligonucleotides, followed by washing and scanning was performed at the Gladstone microarray core facility at the University of California (San Francisco, CA) Keywords: Time series NOD mice (8- to 13-wk-old) were injected s.c. into the lower flanks with 200 micrograms of MOG35–55 peptide (MEVGWYRSPFSRVVHLYRNGK; Auspep) emulsified in CFA containing 4 mg/ml Mycobacterium tuberculosis (Difco). An i.v. injection of 350 ng of Bordetella pertussis toxin was administered both immediately thereafter and 48 h later. The mice in the control group were injected with adjuvant and pertussis toxin only. Disease and control mice were sacrificed at 13 identical timepoints and microarrays were processed for each timepoint.

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