High-throughput 16S rRNA amplicon pyrosequencing of contaminated aquifer sediment
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ABSTRACT:
ORGANISM(S): unidentified
SUBMITTER: Giovanni Pilloni
PROVIDER: E-GEOD-25345 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:The characterization of microbial community structure via 16S rRNA gene profiling has been greatly advanced in recent years by the application of amplicon pyrosequencing. The possibility of barcode-tagged sequencing of templates gives the opportunity to massively screen multiple samples from environmental or clinical sources for community details. However, an on-going debate questions the reproducibility and semi-quantitative rigour of pyrotag sequencing and, as in the early days of genetic community fingerprinting, pros and cons are continuously provided. In this study we investigate the reproducibility of bacterial 454 pyrotag sequencing over biological and technical replicates of natural microbiota. Moreover, via quantitatively defined template spiking to the natural community, we explore the potential for recovering specific template ratios within complex microbial communities. For this reason, we pyrotag sequenced three biological replicates of three samples, each belonging from yearly sampling campaigns of sediment from a tar oil contaminated aquifer in Düsseldorf, Germany. Furthermore, we subjected one DNA extract to replicate technical analyses as well as to increasing ratios (0, 0.2, 2 and 20%) of 16S rRNA genes from a pure culture (Aliivibrio fisheri) originally not present in the sample. Unexpectedly, taxa abundances were highly reproducible in our hands, with max standard deviation of ~3% abundance across biological and ~2% for technical replicates. Furthermore, our workflow was also capable of recovering A. fisheri amendmend ratios in reliable amounts (0, 0.29, 3.9 and 23.8%). These results highlight that pyrotag sequencing, if done and evaluated with due caution, has the potential to robustly recapture taxa template abundances within environmental microbial communities. 9 Biological and 3 technical replicates were evaluated, as well as potential to recover qPCR-defined ratios of DNA, in 454 pyrotag sequencing
2012-07-16 | E-GEOD-35631 | biostudies-arrayexpress
Project description:Contaminated aquifer (Dusseldorf-Flinger, Germany) templates extracted from 5 sediment depths ranging between 6.4 and 8.4 m below ground and over 3 years of sampling were amplified for amplicon pyrosequencing using the primers Ba27f (5’-aga gtt tga tcm tgg ctc ag-3’) and Ba519r (5’- tat tac cgc ggc kgc tg-3’), extended as amplicon fusion primers with respective primer A or B adapters, key sequence and multiplex identifiers (MID) as recommended by 454/Roche. Amplicons were purified and pooled as specified by the manufacturer. Emulsion PCR (emPCR), purification of DNA-enriched beads and sequencing run were performed following protocols and using a 2nd generation pyrosequencer (454 GS FLX Titanium, Roche) as recommended by the developer. Quality filtering of the pyrosequencing reads was performed using the automatic amplicon pipeline of the GS Run Processor (Roche), with a slight modification concerning the valley filter (vfScanAllFlows false instead of TiOnly) to extract the sequences. Demultiplexed raw reads were furhter trimmed for quality and lenght (>250 bp).
2012-11-11 | GSE25345 | GEO
Project description:Bioavailability of electron acceptors is probably the most limiting factor in the restoration of anoxic, contaminated environments. The oxidation of contaminants such as aromatic hydrocarbons, particularly in aquifers, often depends on the reduction of ferric iron or sulphate. We have previously detected a highly active fringe zone beneath a toluene plume at a tar-oil contaminated aquifer in Germany, where a specialized community of contaminant degraders co-dominated by Desulfobulbaceae and Geobacteraceae had established. Although on-site geochemistry links degradation to sulphidogenic processes, dominating catabolic (benzylsuccinate synthase alpha-subunit, bssA) genes detected in situ appeared more related to those of Geobacter spp. Therefore, a stable isotope probing (SIP) incubation of sediment samples with 13C7-toluene and comparative electron acceptor amendment was performed. We introduce pyrosequencing of templates from SIP microcosms as a powerful new strategy in SIP gradient interpretation (Pyro-SIP). Our results reveal the central role of Desulfobulbaceae for sulphidogenic toluene degradation in situ, and affiliate the detected bssA genes to this lineage. This, and the absence of 13C-labelled DNA of Geobacter spp. in SIP gradients preclude their relevance as toluene degraders in situ. In contrast, Betaproteobacteria related to Georgfuchsia spp. became labelled under iron-reducing conditions. Furthermore, secondary toluene degraders belonging to the Peptococcaceae detected in both treatments suggest the possibility of functional redundancy amongst anaerobic toluene degraders on site. 2 samples examined from the different electron-acceptors (sulphate or ferric iron) incubates at the time point of maximal toluene degradation.
2011-03-18 | E-GEOD-25449 | biostudies-arrayexpress
Project description:Chronic acid suppression by proton pump inhibitor (PPI) has been hypothesized to alter the gut microbiota via a change in intestinal pH. To evaluate the changes in gut microbiota composition by long-term PPI treatment. Twenty-four week old F344 rats were fed with (n = 5) or without (n = 6) lansoprazole (PPI) for 50 weeks. Then, profiles of luminal microbiota in the terminal ileum were analyzed. Pyrosequencing for 16S rRNA gene was performed by genome sequencer FLX (454 Life Sciences/Roche) and analyzed by metagenomic bioinformatics.
2015-04-14 | E-GEOD-67800 | biostudies-arrayexpress
Project description:Four cDNA libraries from immature embryos, mature embryos, microspore derived embryos and mature leaves were constructed. cDNA were sequenced by the Roche-454 GS-FLX.
2017-01-11 | E-MTAB-3226 | biostudies-arrayexpress
Project description:Rationale: The cellular and molecular pathways in asthma are highly complex. Increased understanding can be obtained by unbiased transcriptomic analysis (RNA-Seq). Hypothesis and Aims: We hypothesized that the transcriptomic profile of whole human endobronchial biopsies differs between patients with asthma and controls. First, we investigated the feasibility to obtain RNA from whole endobronchial biopsies suitable for RNA-Seq. Second, we examined the difference in transcriptomic profiles between asthma and controls. Methods: This cross-sectional study compared 4 steroid-free atopic asthma patients and 5 healthy non-atopic controls. RNA of ASM from 4 endobronchial biopsies per subject was isolated and sequenced (GS FLX+, 454/Roche). Ingenuity Pathway Analysis was used to identify gene networks. Comparison of the numbers of reads per gene in asthma and controls was based on the Poisson distribution. At the current sample size the estimated false discovery rate was 4%. Results: Yield of isolated RNA was 900-9,300ng. We identified 10,167 and 11,006 unique genes for asthma and controls, respectively. Forty-six genes were differentially expressed between asthma and controls, including pendrin, periostin, and BCL2. Ten gene networks involved in cellular morphology, movement, and development had an IPA network score ≥2. Conclusion:RNA isolated from whole human endobronchial biopsies is suitable for RNA-Seq, showing different transcriptomic profiles between asthma and controls. Novel and confirmative genes were found to be linked to asthma. These results indicate that biological processes in the airways of asthma patients are differently regulated compared to healthy controls, which may be relevant for the pathogenesis and treatment of the disease. This cross-sectional transcriptomics study consisted of 2 visits. At visit 1, atopic asthma patients (n=4), and healthy non-atopic controls (n=5) were screened for eligibility to participate according to the in- and exclusion criteria. Spirometry and a methacholine bronchoprovocation test were performed. At visit 2, FEV1 reversibility was measured and 4 endobronchial biopsies per subject were collected during a bronchoscopy. Total RNA from whole endobronchial biopsies was collected. cDNA was prepared using the Ovation RNA-Seq System (NuGEN). RNA-Seq was performed using the GS FLX+ instrument (454/Roche). Sequence reads were mapped against the human genome (hg19; UCSC). Comparison of the numbers of reads per gene between asthma and healthy controls was based on the Poisson distribution.
2013-01-18 | E-GEOD-38994 | biostudies-arrayexpress
Project description:The small RNAs of Selaginella moellendorffii were sampled by direct pyrosequencing (454 Life Sciences). These data represent microRNAs, siRNAs, and other expressed small RNAs of ~18-~28 nts. in length. Keywords: Small RNA sequencing - high throughput One sample of above-ground tissues of greenhouse-grown S. moellendorffii was used to extract and sequence small RNAs.
2007-06-29 | E-GEOD-7320 | biostudies-arrayexpress
Project description:Rationale: Asthma and atopy shares common features including Th2-inflammation. However, impairment of airway function seems to be absent in atopy. Increased understanding of the complex cellular and molecular pathways defining the similarities and differences between asthma and atopy may be achieved by transcriptomic analysis (RNA-Seq). Hypothesis and Aims: As the airway smooth muscle (ASM) layer plays an important role in airway function, we hypothesized that the transcriptomic profile of the ASM layer in endobronchial biopsies is different between atopic asthma patients and atopic healthy controls. First, we examined the differences in transcriptomic profiles of the ASM layer in endobronchial biopsies between atopic mild, steroid-free asthma patients, and atopic and non-atopic healthy controls. Second, we investigated the association between the transcriptomic profiles of the ASM layer and airway function. Methods: This cross-sectional study included 12 steroid-free atopic asthma patients, 6 atopic, and 6 non-atopic healthy controls. RNA of ASM from 4 endobronchial biopsies per subject was isolated and sequenced (GS FLX+, 454/Roche). Ingenuity Pathway Analysis was used to identify gene networks. Comparison of the numbers of reads per gene in asthma and controls was based on the negative binomial distribution. At the current sample size the estimated false discovery rate was approximately 1%. Results: Yield of isolated RNA was 30-821ng. We identified 174 differentially expressed genes between asthma and atopic controls, 108 between asthma and non-atopic controls, and 135 between atopic and non-atopic controls. A set of 8 genes was identified, which seems to define asthma patients from non-asthmatic controls regardless of atopy. Four of these genes were significantly associated with airway hyperresponsiveness. Conclusion: A difference in transcriptomic profile of the airway smooth muscle layer in asthma patients compared to atopic and non-atopic healthy controls may lead to a different regulation of inflammatory pathways and of airway smooth muscle function and development resulting in impaired airway function. This cross-sectional transcriptomics study consisted of 2 visits. At visit 1, asthma patients (n=12), and healthy atopic (n=6) and non-atopic (n=6) controls were screened for eligibility to participate according to the in- and exclusion criteria. Spirometry and a methacholine bronchoprovocation test were performed. At visit 2, FEV1 reversibility was measured and 4 endobronchial biopsies per subject were collected during a bronchoscopy. Airway smooth muscle was collected from the biopsies by laser capture microdissection and total RNA isolated. cDNA was prepared using the Ovation RNA-Seq System (NuGEN). RNA-Seq was performed using the GS FLX+ instrument (454/Roche). Sequence reads were mapped against the human genome (hg19; UCSC). Comparison of the numbers of reads per gene between asthma and healthy controls was based on the negative binomial distribution and carried out with the R package DESeq including correction for multiple testing.
2014-08-15 | E-GEOD-38003 | biostudies-arrayexpress
Project description:Rationale: Steroids are the mainstay of asthma therapy. However, it is unclear whether the benefits of steroids in asthma are merely based on anti-inflammatory properties. Steroids may also alter gene expression of airway smooth muscle (ASM). Hypothesis and Aims: We hypothesized that the transcriptomic profile of the ASM layer in endobronchial biopsies of atopic asthma patients changes by oral steroid therapy. First, we examined the change in ASM transcriptomic profile in endobronchial biopsies after 14 days of oral steroid therapy. Second, we investigated the association between changes in ASM transcriptomic profile and airway function. Methods: 12 atopic steroid-free asthma patients were included in this double-blind intervention study. Endobronchial biopsies were taken before and after 14 days of oral prednisolon (n=6) or placebo (n=6). RNA of laser-dissected ASM was sequenced (RNA-Seq) using the GS FLX+ System (454/Roche). Gene networks were identified using Ingenuity Pathway Analysis. RNA-Seq reads were assumed to follow a negative binomial distribution. At the current sample size the estimated false discovery rate was approximately 3%. Results: 15 genes were significantly changed by 14 days of oral prednisolon. 2 of these genes (FAM129A, SYNPO2) were associated with the methacholine PC20 (r=0.637, p=0.035; r=0.662, p=0.027). Pathway analysis revealed 3 gene networks that were associated with cellular functions including cellular growth, proliferation, and development. Conclusion: Oral prednisolon changes the gene expression profile of the ASM layer in asthma. This indicates that steroids also exert effects on the transcriptomic level of ASM in addition to their anti-inflammatory properties, which can promote improved airway function. The current randomized, double-blind, parallel, placebo-controlled intervention study comprised 4 visits. At visit 1, asthma patients were screened according to the in- and exclusion criteria prior to enrollment. Additionally, spirometry and methacholine bronchoprovocation test were performed. At visit 2, FEV1 reversibility was measured and endobronchial biopsies were collected during a bronchoscopy. Asthma patients were then prescribed oral prednisolon at a dose of 0.5 mg/kg per day or placebo for 14 consecutive days. The dosage and dosing scheme was based on international recommendations for the treatment of acute exacerbations [1]. On the 11th day after visit 2, the patients visited the lung function laboratory for spirometry and methacholine bronchoprovocation test. Finally, at visit 4 (15th day after visit 2) FEV1 reversibility was measured and endobronchial biopsies were collected by bronchoscopy. Airway smooth muscle was collected from the biopsies by laser capture microdissection and total RNA isolated. cDNA was prepared using the Ovation RNA-Seq System (NuGEN). RNA-Seq was performed using the GS FLX+ instrument (454/Roche). Sequence reads were mapped against the human genome (hg19; UCSC). Comparison of the numbers of reads per gene between the prednisolon and placebo study group was carried out with the R package DESeq.
2013-05-15 | E-GEOD-40996 | biostudies-arrayexpress
Project description:We report the DNA-methylation profiling of 10 regions selected from the DLK1-DIO3 domain on chromosome 14q32 in BM/PB samples from patients with acute promyelocytic leukaemia (APL), other subclasses of acute myeloid leukaemia and healthy donors, using high-throughput amplicon bisulfite sequencing with Roche 454 technology. We identify monoallelic-hypermethylation in APL only at the differentially methylated region (DMR) located upstream from the MEG3 gene (MEG3-DMR), whereas no changes in the DNA methylation profile were detected at the imprinting control region of the domain (IG-DMR) among the samples analysed. We show that the expression profile of 6 miRNAs clustered downstream from the MEG3-DMR correlates with the methylation profile at both DMRs. We demonstrate that miRNAs expression negatively correlates with DNA-methylation at the IG-DMR and MEG3 gene-body, whereas the correlation was positive for the CpGs located in the promoter of MEG3, including the binding sites for the insulator CTCF. We propose a loss of imprinting at the CTCF binding sites in patients with APL. These results are consistent with the previously reported DLK1-DIO3 miRNAs overexpression in APL, indicating a possible involvement of these ncRNAs in the pathogenesis of the disease. Investigation of the epigenetic regulation of the miRNAs clustered in 14q32 by next-generation sequencing
2014-02-13 | E-GEOD-42543 | biostudies-arrayexpress