Technical variation between RNA isolations from individual embryos
Ontology highlight
ABSTRACT:
ORGANISM(S): Danio rerio
SUBMITTER: Mark Jong
PROVIDER: E-GEOD-17738 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Publications
RNA isolation method for single embryo transcriptome analysis in zebrafish.
de Jong Mark M Rauwerda Han H Bruning Oskar O Verkooijen Jurgo J Spaink Herman P HP Breit Timo M TM
BMC research notes 20100316
<h4>Background</h4>Transcriptome analysis during embryogenesis usually requires pooling of embryos to obtain sufficient RNA. Hence, the measured levels of gene-expression represent the average mRNA levels of pooled samples and the biological variation among individuals is confounded. This can irreversibly reduce the robustness, resolution, or expressiveness of the experiment. Therefore, we developed a robust method to isolate abundant high-quality RNA from individual embryos to perform single em ...[more]
Similar Datasets
Project description:Transcriptome analysis during embryogenesis usually requires pooling of embryos to obtain sufficient RNA. Hence, the measured levels of gene-expression represent the average mRNA levels of pooled samples and the biological variation among individuals is lost for inclusion into statistical models used to analyze transcriptome data. This can irreversibly reduce the robustness, resolution and expressiveness of the experiment. Therefore, we developed a robust method to isolate abundant high-quality RNA from individual embryos to perform single embryo transcriptome analyses using the zebrafish as a model. RNA from 8 individual embryos (16-cell, 128-cell, sphere, dome, germ ring, shield, 75%-epiboly & 8-somite stage) was isolated and hybridized against a common reference (pool of these 8 samples).
2010-04-01 | E-GEOD-17736 | biostudies-arrayexpress
Project description:Background; The gut is a major energy consumer, but a comprehensive overview of the adaptive response to fasting is lacking. Gene-expression profiling, pathway analysis, and immunohistochemistry were therefore carried out on mouse small intestine after 0, 12, 24, and 72 hours of fasting. Results; Intestinal weight declined to 50% of control, but this loss of tissue mass was distributed proportionally among the gutâs structural components, so that the microarraysâ tissue base remained unaffected. Unsupervised hierarchical clustering of the microarrays revealed that the successive time points separated into distinct branches. Pathway analysis depicted a pronounced, but transient early response that peaked at 12 hours, and a late response that became progressively more pronounced with continued fasting. Early changes in gene expression were compatible with a cellular deficiency in glutamine and metabolic adaptations directed at glutamine conservation, inhibition of pyruvate oxidation, stimulation of glutamate catabolism via aspartate and phosphoenolpyruvate to lactate, and enhanced fatty-acid oxidation and ketone-body synthesis. In addition, the expression of key genes involved in cell cycling and apoptosis was suppressed. At 24 hours of fasting, many of the early adaptive changes abated. Major changes upon continued fasting implied the production of glucose rather than lactate from carbohydrate backbones, a downregulation of fatty-acid oxidation and a very strong downregulation of the electron-transport chain. Cell cycling and apoptosis remained suppressed. Conclusion; The changes in gene expression indicate that the small intestine rapidly looses mass during fasting to generate lactate or glucose and ketone bodies. Meanwhile, intestinal architecture is maintained by downregulation of cell turnover. Experiment Overall Design: Male FVB mice (Charles River, Maastricht, The Netherlands) were housed at 20-22°C, 50-60% humidity, a 12 hours light/dark cycle, and food and water ad libitum. At 6 weeks of age, mice were fasted by removing chow for up to 72 hours before sacrifice (n = 6 per group). The animals were kept in metabolic cages to prevent the consumption of beddings and were kept warm with an infrared lamp starting at 24h. Experiment Overall Design: All animals were sacrificed between 9:00 and 10:00 a.m. by cervical dislocation. The small intestine was removed quickly in such a way that adherent tissue remained behind. It was opened longitudinally, rinsed in phosphate-buffered saline, blotted, weighed, snap-frozen in liquid N2, and stored at -80°C. We opted to use extracts of full-thickness intestine for gene-expression profiling, because the epithelial component of the murine small intestine comprises over 70% of its volume The suitability of this strategy is underscored by a recent microarray study of transporters in the mouse intestine [Anderle P et al., BMC Genomics 2005, 6: 69.]. In addition, isolation of enterocytes is time-consuming and, hence, entails a risk of mRNA degradation, while mucosal scraping harvests villi more efficiently than crypts , whereas many mRNAs are most abundant in the crypts. Experiment Overall Design: Total intestinal RNA was extracted from frozen tissue with guanidiniumthiocyanate [Chomczynski P, Sacchi N: Analytical Biochemistry 1987, 162: 156-159.], followed by cesium-chloride centrifugation [Glisin V, Crkvenjakov R BC: Biochemistry 1974, 13: 2633-2637.] to avoid contamination with mucus. The quality of RNA was assessed with the RNA 6000 Nano LabChip® Kit in an Agilent 2100 bioanalyzer (Agilent Technologies, Palo Alto, USA). Microarray-based quantification of 8 mRNAs with a 1.3-9.2-fold change in expression was validated by qPCR, as described [58]. mRNA concentration was calculated using the LinReg program [59]. In the absence of reverse transcriptase, the signal was < 0.1% of that in its presence for each primer pair (not shown). Experiment Overall Design: Microarrays. The 60-mer Mouse Development (22K) Oligo Microarray G4120A (Agilent) was used. Three arrays per experimental condition were used. Per microarray, 20 μg mRNA, pooled from 2 intestines, was reverse transcribed with Cy3-labelled dCTP (Perkin Elmer, Boston, USA), using the Agilent Fluorescent Direct Label Kit. Cy5-labeled cDNA produced from RNA pooled from 6 fed animals served as the common reference across all arrays (Figure 1A). Hybridized cDNAs were detected with Agilentâs dual-laser microarray slide scanner. The data were retrieved with Agilentâs Feature Extraction software 6.1.1.
2009-05-13 | E-GEOD-8019 | biostudies-arrayexpress
Project description:A comparative transcriptome approach was used to assess genes involved in metabolism and pathogenesis that are specifically activated during anaerobic growth of the spore-forming food-borne human pathogen Bacillus cereus ATCC 14579. Growth under anaerobic conditions in Brain Heart Infusion broth revealed a reduced growth rate and a lower yield as compared to that under aerobic conditions. Comparative transcriptome analysis of cells harvested at early- and mid-exponential growth phase, transition phase and stationary phase, subsequently showed hundreds of genes to be induced under anaerobic condition. These included novel genes identified for anaerobic growth of B. cereus, encoding metabolic pathways, such as the arginine deiminase pathway (ArcABDC), a formate dehydrogenase (FdhF) and a pyruvate fomate lyase (Pfl), and alternative respiratory proteins, such as arsenate reductases. Furthermore, the nitrosative stress response was induced in the anaerobic transition phase of growth, conceivably due to the production of nitric oxide as a by-product of nitrite and nitrate respiration. Notably, both hemolytic enzyme and enterotoxin encoding genes were activated in different oxygen limiting conditions, i.e. hemolytic enzyme encoding genes were induced during anaerobic growth, whereas enterotoxin encoding genes were induced in the transition and stationary phase of aerobic cultures reaching a high cell density. These data point to metabolic rearrangements, stress adaptation and activation of the virulent status of B. cereus under anaerobic conditions, such as encountered in the human GI-tract. B. cereus ATCC 14579 was grown in BHI in 50 ml. Aerobic in a Erlenmeyer flask, shaking at 200 rpm. Anaerobic in a closed flask, flushed with Nitrogen-gas for 30 min, also shaking at 200 rpm. Transcriptome analyses Phase compared to mid-exponential phase Anaerobic (OD600) 0.2 compared to 0.4 Early-exponential 1.0 compared to 0.4 Transition 1.1 compared to 0.4 Stationary Aerobic (OD600) 0.2 compared to 0.8 Early-exponential 4.0 compared to 0.8 Transition 8.0 compared to 0.8 Stationary Aerobic to anaerobic (OD600) Anaerobic 0.6 to aerobic 0.6
2008-05-11 | E-GEOD-9846 | biostudies-arrayexpress
Project description:A common bacterial strategy for monitoring environmental challenges is to use two-component systems, which consist of a sensor histidine kinase (HK) and a response regulator (RR). In the food-borne pathogen Bacillus cereus, the alternative sigma factor ÏB is activated by the RR RsbY. Here we present strong indications that the PP2C-type phosphatase RsbY receives its input from the multi-sensor hybrid kinase BC1008 (renamed RsbK). Genome analyses revealed that, across bacilli, rsbY and rsbK are located in a conserved gene cluster. A B. cereus rsbK deletion strain was shown to be incapable of inducing ÏB upon stress conditions and was impaired in its heat adaptive response. Comparison of the wild-type and rsbK mutant transcriptomes upon heat shock revealed that RsbK was primarily involved in the activation of the ÏB-mediated stress response. Truncation of the RsbK RR receiver domain demonstrated the importance of this domain for ÏB induction upon stress. The domain architecture of RsbK suggests that in the B. cereus group and in other bacilli, environmental and intracellular stress signalling routes are combined into one single protein. This strategy is markedly different from the ÏB activation pathway in other low-GC Grampositives. Two different comparisons were performed (both in duplo and Cy5-Cy3 dye-swapped): (1) B. cereus WT 30°C versus B. cereus WT 42°C (10 min heat shock) (2) B. cereus WT 42°C versus B. cereus FM1404 42°C Data from comparisons (2) were subsequently compared with transcriptome data obtained previously by Van Schaik et al., 2007
2010-06-24 | E-GEOD-14589 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE13711: Comparative transcriptome and phenotype analysis of acid-stressed Bacillus cereus strain ATCC 14579 GSE13729: Comparative transcriptome and phenotype analysis of acid-stressed Bacillus cereus strain ATCC 10987 Refer to individual Series
2010-06-25 | E-GEOD-13773 | biostudies-arrayexpress
Project description:The food-borne human pathogen Bacillus cereus is found in environments that often have a low pH, such as food and soil. The physiological response upon exposure to several levels of acidity were investigated of B. cereus model strain ATCC 14579, to elucidate the response of B. cereus to acid stress. pH 5.4, pH 5.0, pH 4.8 and pH 4.5 were selected to conduct microarray analyses, based on the differences in physiological response upon exposure to the acid conditions. The transcriptome data revealed response specific profiles. Showing mechanisms induced upon all the different acid down-shocks, such as nitrate reductase and energy production genes, and several genes specifically expressed differentially in mild or lethal levels of acidity, such as F1F0-ATPase and cydAB. Furthermore, mechanisms involved in oxidative stress response were found highly up-regulated in response to both mild and lethal acid stress. The induction of oxidative stress related genes may be a response to the formation of reactive oxygen species by a perturbation of the electron transport chain. Therefore, the formation of hydroxyl radicals and/ or peroxynitrite was monitored upon exposure to the different levels of acidity with a fluorescent probe in a flow cytometer. The formation of these oxidative compounds was shown to be specific for lethal pHs and a model to relate radical formation with the observed transcriptome profiles was proposed. Per acid down-shock three exposure times (i.e., 10, 30 and 60 min) were each compared with non-exposed cells (i.e., t0). In total 4 different acid down-shocks were applied, pH 5.4, pH 5.0, pH 4.8 and pH 4.5. The experiments were performed in duplicate and the duplicate samples were hybridised with a dye-swap.
2010-06-25 | E-GEOD-13711 | biostudies-arrayexpress
Project description:Here, the role of σM and its regulon in stress response and survival of B. cereus ATCC 14579 was assessed by comparative transciptome and phenotypic analysis of this strain and its sigM deletion strain. Exposure of B. cereus ATCC 14579 to a wide range of stresses revealed expression of sigM, encoding σM, to be up-regulated mainly in the presence of ethanol and after alkaline pH-shock. Next to this, disc diffusion tests showed the sigM deletion strain to be more sensitive to oxidizing agents and to be more resistant to cell-wall targeting antibiotics than the wild-type strain. The σM regulon was subsequently determined by comparative transcriptional analyses of the wild-type and its sigM-deletion strain after exposure to ethanol. The putative σM-regulon was shown to consist of 29 genes, several of these genes are predicted to be involved in counteracting oxidative stress, such as an NADH oxidase, a ferredoxin, and a lysine decarboxylase or could encode enzymes involved in methionine metabolism, leading toward L-cysteine production, including luxS. Screening of promoter upstream regions allowed for the assessment of a B. cereus consensus promoter binding site for σM. Since the consensus promoter binding site for B. cereus ATCC 14579 σM, its regulon and the predicted functionalities are different from the corresponding features in B. subtilis, it can be concluded that σM plays a unique role in B. cereus stress response and survival. The sigM deletion strain of B. cereus ATCC 14579 was cultured to an OD600 of ~0.6. Here the first RNA sample was taken, 0 min. After sampling 4% of ethanol was added (v/v), and samples were taken after 10, 30 and 60 minutes of exposure. Comparisons performed were 0 min - 10 min, 0 min - 30 min, and 0 min - 60 min.
2008-05-11 | E-GEOD-9856 | biostudies-arrayexpress
Project description:The stress response of B. cereus ATCC 14579 is monitored true time, showing an enormous response in gene expression. The wild-type strain of B. cereus ATCC 14579 was cultured to an OD600 of ~0.6. Here the first RNA sample was taken, 0 min. After sampling 4% of ethanol was added (v/v), and samples were taken after 10, 30 and 60 minutes of exposure. Comparisons performed were 0 min - 10 min, 0 min - 30 min, and 0 min - 60 min.
2008-05-11 | E-GEOD-9855 | biostudies-arrayexpress
Project description:Bacteria are able to cope with the challenges of sudden increase of salinity by activating adaptation mechanisms. In this study, exponentially growing cells of the food-borne pathogen Bacillus cereus ATCC 14579 were exposed to both mild (2.5% NaCl w/v) and severe (5% NaCl w/v) salt stress conditions. B. cereus continued growth at a reduced rate when shifted to mild salt stress. Exposure to severe salt stress resulted in a lag period, and after 60 min cellular growth was resumed filamentously. Whole-genome expression analyses of cells exposed to 2.5% salt stress revealed an overlap with that of cells exposed to 5% salt stress, suggesting that the corresponding genes (n = 147) were involved in a general salt stress response. Up-regulation of osmolyte, Na+/H+ and di-/tripeptide transporters and activation of an oxidative stress response were important aspects of this general salt stress response. Activation of this response may confer cross-protection towards other stresses, and increased resistance to heat and H2O2 was indeed observed. Notably, a temporal shift was observed between the observed transcriptome and phenotype responses of severely salt-stressed cells including cellular filamentation, reduced chemotaxis performance, catalase activity and optimal oxidative stress resistance. The linkage of transcriptomes and phenotypic characteristics can contribute to a better understanding of cellular stress adaptation strategies and possible cross protection mechanisms. ATCC 14579 was grown to an OD600 of ~0.5, after that 2.5% or 5% NaCl (w/v) was added. Before addition of NaCl and after 10, 30 and 60 minutes of NaCl-exposure a sample was taken for RNA isolation. Comparisons (untreated versus salt-treated) performed were in duplicate with dye swap.
2010-06-24 | E-GEOD-13713 | biostudies-arrayexpress
Project description:The stress response of as sigZ deletion strain of B. cereus ATCC 14579 is monitored true time by use of microarrays. The sigZ regulon in ethanol stress response was determined and compared with the regulon determined by micorarray analysis of overexpression of sigZ. The sigZ deletion strain of B. cereus ATCC 14579 was cultured to an OD600 of ~0.6. Here the first RNA sample was taken, 0 min. After sampling 4% of ethanol was added (v/v), and samples were taken after 10, 30 and 60 minutes of exposure. Comparisons performed were 0 min - 10 min, 0 min - 30 min, and 0 min - 60 min.
2008-05-10 | E-GEOD-9858 | biostudies-arrayexpress