Dataset Information

Synechocystis sp. PCC 6803 response to inorganic carbon limitation

ABSTRACT: Synechocystis 6803 cells was grown photoautotrophically at 32 °C buffered in BG-11 and bubbled with 3% CO2. A relatively mild Ci stress was applied by switching the aeration from 3% CO2 to air alone. After incubation under designated conditions, a 100-ml aliquot of culture was immediately combined with an equal volume of ice-cold mixture of phenol and ethanol (1:10, w/v) in an ice bath. The resultant cells were collected by centrifugation at 1000 x g for 10 min at 4 °C. Total RNA was isolated with RNeasy Midi Kit (Qiagen, Valencia, CA) and further treated with the DNA-free kit (Ambion, Austin, TX). Fluorescently labeled cDNA was produced via a two-step indirect procedure involving cDNA synthesis from 16 µg of total RNA in a reverse transcriptase reaction incorporating aminoallyl-modified deoxynucleotide, followed by the second step involving chemical coupling of fluorescent dye to the introduced amino moieties of the synthesized cDNA. Labeled cDNA were adjusted to 14.75 µl, and the remainder of the hybridization components containing 2.5 µl of 10 µg µl-1 salmon sperm DNA, 8.75 µl of 20x SSC, 0.25 µl of 10% SDS, and 8.75 µl of formamide were added. The mixture was then heated for 2 min at 99 °C and maintained at 42 °C until hybridization. Hybridizations were preformed in a static incubator at 42 °C for 12-16 h then washed by placing in a 250-ml solution of 2x SSC and 0.1% SDS at 42 °C for 5 min with gentle agitation provided by rotation of a magnetic stir bar. The slide was transferred quickly to a 250-ml solution of 0.1x SSC and 0.1% SDS, incubated for 10 min at room temperature with gentle agitation, and washed five additional times in 0.1x SSC for 1 min at room temperature. Hybridization signals from the microarray were quantified using GenePix Pro 4.1 (Axon Instruments, Union City, CA). The quality control procedures were conducted in the image analysis software, and then data were saved to Acuity 3.1 (Axon Instruments). Keywords: time-course

ORGANISM(S): Synechocystis sp. PCC 6803

PROVIDER: GSE1695 | GEO | 2004/08/24

SECONDARY ACCESSION(S): PRJNA90659

REPOSITORIES: GEO

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Project description:Batch cultures of Wild-type C. jejuni NCTC11168 were grown in 150 ml volumes of Mueller-Hinton broth in 250 ml baffled flasks. Microaerophilic conditions were generated using a MACS-VA500 microaerophilic work station (10 % O2, 10 % CO2, 80 % N2) from Don Whitley Scientific, Ltd which also maintained the growth temperature at 42 ÂºC. When mid-exponential phase was reached 0.25 mM GSNO was added to half of the cultures. After a 10 minute exposure samples of both treated and untreated cells were harvested into phenol/ethenol to stabilize the RNA and total RNA was purified using Qiagenâs RNeasy Mini kit (as recommended by the suppliers) prior to use in microarray analysis. A C. jejuni cgb mutant was grown in two parallel custom-built chemostats based on Sigma Proculture Dynalift spinner flasks with a working volume of 125 ml, and the dilution rate (which at steady state is equal to the specific growth rate) of 0.1 h-1. A gas mix of 10% O2, 10% CO2 and 80% N2 was passed into the head space of the culture vessel at a rate of 0.25 l min-1 to obtain a microaerobic atmosphere, and silicone water jackets maintained the temperature at 42 ÂºC. The flasks were placed on KMO 2 basic IKA-Werke stirrers (arbitrary setting, 260; Scientific Laboratory Supplies), which gaveeffective transfer of O2 from the gaseous atmosphere to the culture by virtue of a stable vortex. A fresh overflow sample was used to check the pH at the time of harvest (which was consistently between 6.6 and 7) and to ensure that there was no contamination by plating a 20 Î¼l sample onto both nutrient agar plates incubated at 37 Â°C at atmospheric oxygen, and Mueller-Hinton plates incubated at 42 Â°C in the microaerophilic work station. When staedy-state was reached, as verified by collecting at least 5 culture volumes, GSNO (final concentration 0.25 mM) was added to one culture. After a further 10 min the 125 ml volume was separated into 3 equal volumes and each was mixed immediately on ice with 3.56 ml 100% ethanol and 185 ml phenol to stabilize the RNA. The cells were subsequently harvested by centrifugation. Total RNA was purified by using a Qiagen RNeasy Mini kit as recommended by the supplier. cDNA synthesis was carried out using 12 Âµg of starting material, which was primed with 9 Âµg of pd(N)6 random hexamers (Amersham Biosciences). Reaction mixtures (20 Âµl) containing 0.5 mM ATP, 0.5 mM TTP, 0.5 mM GTP, 0.2 mM CTP, and 1 mM Cy3- or 1 mM Cy5-dCTP were incubated for 2 h at 42 Â°C with 200 U of Superscript II RNase H reverse transcriptase (Invitrogen). Following synthesis, cDNA was purified by using a PCR purification kit (Qiagen) to remove the unincorporated deoxynucloside triphosphates, fluorescent dye, and primers. Equal volumes of cDNA were combined and evaporated to near dryness with an SPD121P Speed Vac (Thermon Savant). For hybridisation to the microarray slides, cDNA was resuspended in an appropriate volume of salt-based hybridization buffer (provided by Ocimum Biosolutions). Prior to addition to the slides, cDNA samples were heated to 95 Â°C for 3 min, and then placed on ice for no more than 3 min. The slides were placed in MWG Biotech hybridization chambers and incubated for 16 to 24 h in a shaking water bath at 110 rpm and 42 Â°C. Following incubation , the slides were washed sequentially for 5 min in 2x SSC-1 % sodium dodecyl sulphate, 1x SSC, 0.5x SSC and 0.1x SSC at 37 Â°C with gentle agitation (1x SSC is 0.15 M NaCl plus 0.015 M sodium citrate). The slides were dried by centrifugation at 254 xg for 5 min and subsequently scanned with an Affymetrix 428 scanner. The average signal intensity and local background correction were obtained by using commercially available software from Biodiscovery, Inc. (Imagine version 4.0, and Genesight, version 3.5). The mean values from each channel were log2 transformed and normalized by using the subtract-by-mean method to remove intensity-dependent effects in the log2 (ratio) values. The Cy3/Cy5 fluorescence ratios were calculated from the normalized values. Biological experiments (i.e. chemostat growth with and without 0.25 mM GSNO addition) were carried out three times and a dye swap was performed for two of the three experiments which provided two technical repeats, one each for two of the three biological repeats. Data from the independent experiments were combined. Genes that were differentially expressed â¥ twofold and displayed and P value of â¤ 0.05 (as determined by a t test) were defined as being statistically significantly differentially transcribed.

Project description:To identify mRNAs associated with human PUM2 protein, we used a modified Ribonucleoprotein-ImmunoPrecipitation Microarray (RIP-Chip) approach on HeLa S3 cancer cells that express PUM2. PUM ribonucleoprotein (RNP) complexes were captured from cell-free extracts with specific anti PUM2 antibody coupled to protein A sepharose beads, and then eluted with SDS-EDTA. To control for non-specifically enriched RNAs, the same procedure was performed with beads that were not coupled with immunoprecipitating antibodies (mock samples). Total RNA was isolated from cell extracts and immunopurified samples with the mirVanaTM PARISTM kit (Ambion). RNA was quantified with a NanoDrop device (Witeg AG). Poly-adenylated RNAs were amplified in the presence of aminoallyl-UTP with Amino Allyl MessageAmp II aRNA kit (Ambion). For this purpose, 500 ng total RNA from extracts and half (50-100 ng) of the immunopurified RNAs were used for amplification. 8 ug of the amplified RNAs (aaRNA) were fluorescently labeled with NHS-monoester Cy3 and Cy5 dyes (GE HealthSciences), except for mock RNA samples, where an aaRNA amount proportional to the yield obtained from corresponding PUM affinity isolates was used.For PUM2 RIPs, we performed four biological replicates but omitted the dye swaps due to the lower aaRNA obtained after amplification (~10 ug aaRNA from PUM2 RIPs, 9 ug aaRNA from mock RIPs). The Cy3- and Cy5-labeled aaRNA samples were mixed and hybridized to human cDNA microarrays. Detailed methods for microarray experiments are available at http://cmgm.stanford.edu/pbrown/protocols/index.html. cDNA microarrays were produced by the Stanford Functional Genomic Facility and contained 43,197 human probes representing 26,524 Unigene cluster IDs (12,466 ENSEMBL annotated genes) spotted on Corning Ultra GAPS slides. Spotted cDNAs were cross-linked with 65 mJ of UV irradiation on slides, which were then post-processed for 1 hour at 42°C in pre-hybridization solution (5x SSC, 0.1% SDS, 0.1 mg/ml BSA), washed twice in 400 ml of 0.1x SSC for 5 min, dunked in 400 ml ultrapure water for 30 sec, and dried by centrifugation at 550 rpm for 5 min. Slides were used the same day. Cy3- and Cy5-labeled aaRNA probes were mixed and applied to arrays in hybridization solution (3x SSC, 20 ug poly(A) RNA [Invitrogen], 20 ug yeast tRNA [Invitrogen], 20 ug Human Cot-1 DNA [Invitrogen], 20 mM HEPES [pH 7.0] and 0.3% SDS) for 18 h at 65°C. The arrays were then washed sequentially in 400 ml of 2x SSC with 0.1% SDS, 1x SSC, and 0.2x SSC. The first wash was performed for 5 min at 65°C, the subsequent washes were performed for 5 min at RT. The arrays were dried by centrifugation and immediately scanned with an AxonScanner 4200A (Molecular Devices). Data were collected using GENEPIX 5.1 (Molecular Devices). Arrays were normalized computationally by the Stanford Microarray Database (SMD). The data were filtered for signal over background of greater than 1.5 in the channel measuring aaRNA from extract, and only features that met these criteria in > 50% of the arrays were included for further analysis. Log2 median ratios were retrieved and exported into Microsoft Excel. To identify transcripts that were specifically enriched by association with PUM2, we performed two class Significance Analysis of Microarrays (SAM) on median centered arrays. A replicate experimental design type is where a series of replicates are performed to evaluate reproducibility or as a pilot study to determine the appropriate number of replicates for a subsequent experiments. Antibody used in IP: 50 ug rabbit anti-PUMILIO 2 (Bethyl Laboratories, #300-202A) Keywords: replicate_design

Project description:This series repressents the data set from the paper "Expression microarray analysis and oligo array CGH of aquired gemcitabine resistance in mouse colon reveals selection for chromosomal aberrations". Biological material: One solid mouse tumor "Colon 26A" was routinely maintained by successive transplantation. A subset of mice with this tumor was treated at the maximum tolerable dosage of Gemcitabine and successively transplanted 5 times and similarly treated. The last passage was completly resistant and designated, "Colon 26G". Expression array: Total RNA was isolated from frozen mouse tumors using Tryzol. Single stranded cDNA was synthetized from 30 mg of total RNA by reverse transcription using aminoallyl labeled dUTP (Ambion). Labelling was performed according to the aminoallyl labeling protocol. Briefly, cDNA was incubated at room temperature for 1 h with fluorolink monofunctional cy5 or cy3 (Amersham) followed by 15 min 4 M hydroxylamine treatment. Uncoupled dyes were removed using Qiaquick PCR purification columns (Qiagen) and mixed with 12 mg poly(dA) (Amersham), 60 mg yeast tRNA (Sigma) and 24 mg Cot-1 DNA (Invitroen). The probe was dissolved in 127 ml hybridization mixture containing 46% formamide, 9.5% dextran sulfate, 2x SSC and 0.2% SDS. The probe was heated to 70°C for 10 min and annealed at 37°C for 1 h. Slides were hybridized for 14 h at 37°C over-night (HyArray 12™, Perkin Elmer). After hybridization the slides were washed in the HybArray 12™ with 50% formamide, 2x SSC, pH 7 at 35°C for 15 min, followed b PI buffer (0.1 M sodium phosphate, 0.1% Igepal Ca630, pH 8) at room temperature and 3 washes of 0.2x SSC, 0.1x SSC and 0.01x SSC at room temperature followed by centrifugation. Arrays were scanned using a laser scanner (ScanArray Express, Perkin Elmer) and analysed using ImaGene version 5.6. Cy5 cy3 ratios are calculating by taking the log2 of the signal mean of each spot minus the median background mean of all spots on the array. This is followed by a standard normalization for spot intensity and calculation of the ratios. Keywords: other

Project description:Ambient temperature affects organisms comprehensively, however cold responses are different among tissues. Here, we adopt a transcript screening approach to explore and compare the cold responses in zebrafish gills and brain. Zebrafish were exposed to cold and the oligonucleotide-based microarray was used to identify cold-induced genes. Principle component analysis (PCA) of the gene expression profiles indicated that gills develop different strategies for the increasing of exposure period while brain relatively remained stable. Combining statistic and clustering methods, we found that gills showed higher protein metabolism and cell activity while brain showed higher stress responses and detoxification during cold acclimation. According to the microarray data sets, we extended the study on ionocyte- and isotocin neuron-related genes in gills and brain, respectively, and found these genes were broadly stimulated by cold. These data suggest that cold activates specific physiological functions in different tissues. Taken together, our results provide molecular evidences to elucidate the cold acclimation in zebrafish gills and brain. Keywords: Time course, Tissue types After the low-temperature treatment, brain and gill tissues dissected from 10 individuals were pooled as a sample and then homogenized in 0.8 ml Trizol reagent (Invitrogen, Carlsbad, CA). 120 individuals (60 for low-temperature treatment and 60 for control) were sacrificed for each microarray hybridization experiment, and another 200 individuals were used for quantitative reverse-transcription polymerase chain reaction. After chloroform extraction, RNA precipitation and ethanol washing, the RNA samples were purified and treated with DNase1 to remove the genomic DNA by using RNeasy Mini Kit (Qiagen, Huntsville, Alabama). The quantity and quality of total RNA were assessed by spectrophotometry and Bioanalyzer (Aglient Technologies, Foster City, CA). The commercial zebrafish 14K oligonucleotides set (MWG Biotech AG, Ebersbach, Germany) were obtained and were printed on UltraGAPS Coated slide (Corning, New York, NY ) with use of the OmniGrid 100 microarrayer (Genomic Solutions, Ann Arbor, MI) according to the manufactureâ??s instructions. The 14,067 oligonucleotides represent 9666 genes (7009 singlet genes and 2657 redundant genes), and the redundancy of this chip is 31 %. The detailed description of the oligonucleotides information can be obtained on the Ocimun Biosolution website. cDNA probes were synthesized and purified by reverse transcription of 20 Î¼g total RNA using a SuperScript indirect cDNA labeling system (Invitrogen) and MinElute PCR purification kit (Qiagen) and were labeled with Alexa 647 dye (cold treatment groups) and Alexa 555 dye (control groups)(Invitrogen), respectively. The zebrafish 14K OciChip array chip was pretreated with 1% bovine serum albumin (BSA) (fraction V), 4x saline-sodium citrate (SSC), and 1% sodium dodecylsulfate (SDS) at 42 Â°C for 45 min, and then hybridized overnight in a cocktail containing 5x Denhardt's solution, 6x SSC, 0.5% SDS, 50% formamide, 50 mM sodium phosphate, and 2 Âµg/Âµl yeast tRNA. Slides were washed with 2x SSC and 0.1% SDS (5 min), 1x SSC and 0.1% SDS (5 min), 0.5x SSC (5 min), and twice with 0.1x SSC (2 min each). Scanning was performed with a Genepix scanner (Molecular Devices, Sunnyvale, CA). The acquired images were analyzed using Genepix and Genespring software (Aglient Technologies, Foster City, CA). The measurements of spots were filtered by flags, and the Lowess normalization was performed after subtraction of the median background. Each experiment contained 3 biological replicates (including 1 dye swap) with different samples. The differentially expressed genes were selected from those with at least 2 of 3 significant signals (ratio > 2 or < 0.5), and then the Significant Analysis of Microarray method (SAM 3.02) was used to determine statistical significances.

Project description:Wild-type Campylobacter jejuni NCTC11168 was grown in 2 homemade, parallel chemostats. Cells were grown in 125 ml volumes of Mueller-Hinton Broth where the growth rate was controlled by the dilution rate (0.1 h-1). A gas mix of 80% nitrogen, 10% carbon dioxide and 10% oxygen was pumped into the head-space of the vessels at a rate of 0.25 l/min to obtain a microaerobic environment and the culture was maintained at 42 ÂºC via a water jacket. Cells were grown as above until steady-state had been reached. At steady-state one of the cultures was exposed to 10 uM NOC-5 & -7 (final concentration) for a period of 10 min. Samples of both the control and stressed cultures were harvested into phenol/ethanol to stabilize the RNA and total RNA was purified using Qiagenâ??s RNeasy Mini kit (as recommended by the suppliers) prior to use in microarray analysis. Equal quantities of RNA from control and GSNO-supplemented cultures were labelled using nucleotide analogues of dCTP containing either Cy3 or Cy5 fluorescent dyes. The average signal intensity and local background correction were obtained using a commercially available software package from Biodiscovery, Inc (Imagene, version 4.0 and GeneSight, version 4). The mean values from each channel were log2 transformed and normalised using the Lowess method to remove intensity-dependent effects in the log2(ratios) values. The Cy3/Cy5 fluorescent ratios were calculated from the normalized values. C. jejuni NCTC11168 was grown in two parallel custom-built chemostats based on Sigma Proculture Dynalift spinner flasks with a working volume of 125 ml, and the dilution rate (which at steady state is equal to the specific growth rate) of 0.1 h-1. A gas mix of 10% O2, 10% CO2 and 80% N2 was passed into the head space of the culture vessel at a rate of 0.25 l min-1 to obtain a microaerobic atmosphere, and silicone water jackets maintained the temperature at 42 ÂºC. The flasks were placed on KMO 2 basic IKA-Werke stirrers (arbitrary setting, 260; Scientific Laboratory Supplies), which gaveeffective transfer of O2 from the gaseous atmosphere to the culture by virtue of a stable vortex. A fresh overflow sample was used to check the pH at the time of harvest (which was consistently between 6.6 and 7) and to ensure that there was no contamination by plating a 20 Î¼l sample onto both nutrient agar plates incubated at 37 Â°C at atmospheric oxygen, and Mueller-Hinton plates incubated at 42 Â°C in the microaerophilic work station. When staedy-state was reached, as verified by collecting at least 5 culture volumes, NOC-5 & -7 (final concentration 10 uM) was added to one culture. After a further 10 min the 125 ml volume was separated into 3 equal volumes and each was mixed immediately on ice with 3.56 ml 100% ethanol and 185 ml phenol to stabilize the RNA. The cells were subsequently harvested by centrifugation. Total RNA was purified by using a Qiagen RNeasy Mini kit as recommended by the supplier. cDNA synthesis was carried out using 12 Âµg of starting material, which was primed with 9 Âµg of pd(N)6 random hexamers (Amersham Biosciences). Reaction mixtures (20 Âµl) containing 0.5 mM ATP, 0.5 mM TTP, 0.5 mM GTP, 0.2 mM CTP, and 1 mM Cy3- or 1 mM Cy5-dCTP were incubated for 2 h at 42 Â°C with 200 U of Superscript II RNase H reverse transcriptase (Invitrogen). Following synthesis, cDNA was purified by using a PCR purification kit (Qiagen) to remove the unincorporated deoxynucloside triphosphates, fluorescent dye, and primers. Equal volumes of cDNA were combined and evaporated to near dryness with an SPD121P Speed Vac (Thermon Savant). For hybridisation to the microarray slides, cDNA was resuspended in an appropriate volume of salt-based hybridization buffer (provided by Ocimum Biosolutions). Prior to addition to the slides, cDNA samples were heated to 95 Â°C for 3 min, and then placed on ice for no more than 3 min. The slides were placed in MWG Biotech hybridization chambers and incubated for 16 to 24 h in a shaking water bath at 110 rpm and 42 Â°C. Following incubation , the slides were washed sequentially for 5 min in 2x SSC-1 % sodium dodecyl sulphate, 1x SSC, 0.5x SSC and 0.1x SSC at 37 Â°C with gentle agitation (1x SSC is 0.15 M NaCl plus 0.015 M sodium citrate). The slides were dried by centrifugation at 254 xg for 5 min and subsequently scanned with an Affymetrix 428 scanner. The average signal intensity and local background correction were obtained by using commercially available software from Biodiscovery, Inc. (Imagine version 4.0, and Genesight, version 3.5). The mean values from each channel were log2 transformed and normalized by using the subtract-by-mean method to remove intensity-dependent effects in the log2 (ratio) values. The Cy3/Cy5 fluorescence ratios were calculated from the normalized values. Biological experiments (i.e. chemostat growth with and without 0.25 mM GSNO addition) were carried out three times and a dye swap was performed for two of the three experiments which provided two technical repeats, one each for two of the three biological repeats. Data from the independent experiments were combined. Genes that were differentially expressed â?¥ twofold and displayed and P value of â?¤ 0.05 (as determined by a t test) were defined as being statistically significantly differentially transcribed.

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