Filters
Technology
Platform
SRP019833
Saccharomyces cerevisiae
24 Downloadable Samples
Illumina Genome Analyzer IIx
Description
Transfer RNA (tRNA) modifications enhance the efficiency, specificity and fidelity of translation in all organisms. The anticodon modification mcm5s2U34 is required for normal growth and stress resistance in yeast; mutants lacking this modification have numerous phenotypes. Mutations in the homologous human genes are linked to neurological disease. The yeast phenotypes can be ameliorated by overexpression of specific tRNAs, suggesting that the modifications are necessary for efficient translation of specific codons. We determined the in vivo ribosome distributions at single codon resolution in yeast strains lacking mcm5s2U. We found accumulations at AAA, CAA, and GAA codons, suggesting that translation is slow when these codons are in the ribosomal A site, but these changes appeared too small to affect protein output. Instead, we observed activation of the GCN4-mediated stress response by a non- canonical pathway. Thus, loss of mcm5s2U causes global effects on gene expression due to perturbation of cellular signaling. Overall design: WT yeast and mutants lacking anticodon tRNA modifications were grown in YPD, and subjected to ribosome footprint profiling (ribo-seq) and RNA-seq of poly-A selected RNA. Dataset contains biological replicates for WT, ?ncs6 and ?uba4. Technical replicates were also performed for all RNA-seq datasets (using a different poly-A selection method).
Publication Title
Loss of a conserved tRNA anticodon modification perturbs cellular signaling.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 8 Downloadable Samples
Affymetrix Human Exon 1.0 ST Array [transcript (gene) version (huex10st)
Description
Background: The vast majority of human genes (.70%) are alternatively spliced. Although alternative pre-mRNA processing is modified in multiple tumors, alternative hyper-splicing signatures specific to particular tumor types are still lacking. Here, we report the use of Affymetrix Human Exon Arrays to spot hyper-splicing events characteristic of myasthenia gravis (MG)-thymoma, thymic tumors which develop in patients with MG and discriminate them from colon cancer changes. Methodology/Principal Findings: We combined GO term to parent threshold-based and threshold-independent ad-hoc functional statistics with in-depth analysis of key modified transcripts to highlight various exon-specific changes. These denote alternative splicing in MG-thymoma tumors compared to healthy human thymus and to in-house and Affymetrix datasets from colon cancer and healthy tissues. By using both global and specific, term-to-parent Gene Ontology (GO) statistical comparisons, our functional integrative ad-hoc method allowed the detection of disease-relevant splicing events. Conclusions/Significance: Hyper-spliced transcripts spanned several categories, including the tumorogenic ERBB4 tyrosine kinase receptor and the connective tissue growth factor CTGF, as well as the immune function-related histocompatability gene HLA-DRB1 and interleukin (IL)19, two muscle-specific collagens and one myosin heavy chain gene; intriguingly, a putative new exon was discovered in the MG-involved acetylcholinesterase ACHE gene. Corresponding changes in spliceosome composition were indicated by co-decreases in the splicing factors ASF/SF2 and SC35. Parallel tumor-associated changes occurred in colon cancer as well, but the majority of the apparent hyper-splicing events were particular to MGthymoma and could be validated by Fluorescent In-Situ Hybridization (FISH), Reverse TranscriptionPolymerase Chain Reaction (RT-PCR) and mass spectrometry (MS) followed by peptide sequencing. Our findings demonstrate a particular alternative hyper-splicing signature for transcripts over-expressed in MG-thymoma, supporting the hypothesis that alternative hyper-splicing contributes to shaping the biological functions of these and other specialized tumors and opening new venues for the development of diagnosis and treatment approaches
Publication Title
Identifying alternative hyper-splicing signatures in MG-thymoma by exon arrays.
Sample Metadata Fields
Sex
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Extrahepatic bile ducts were isolated from mouse pups at days 0-3 and primary cholangiocytes were isolated. Cholangiocytes were treated with DMSO, bilatresone (TOX4), betavulgarin (TOX2), and isoflavanone (TOX3), as per Lorent et al, Science Translationa Medicine 2015;286:286ra67 (Fig. 1), all in DMSO. Treatment concentrations were 2.0 micrograms/ml, for 6 hours.
Publication Title
Extrahepatic cholangiocyte obstruction is mediated by decreased glutathione, Wnt and Notch signaling pathways in a toxic model of biliary atresia.
Sample Metadata Fields
Treatment
View Samples- Populus trichocarpa
- 9 Downloadable Samples
- Affymetrix Poplar Genome Array (poplar)
Description
Embolism and the refilling of xylem vessels are intrinsic to the ability of plants to handle the transport of water under tension. While the formation of an embolized vessel is an abiotic process, refilling against the pressure gradient requires biological activity to provide both the energy and the water needed to restore xylem transport capacity.
Publication Title
Transcriptome response to embolism formation in stems of Populus trichocarpa provides insight into signaling and the biology of refilling.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Genome instability is a potential limitation to the research and therapeutic application of induced pluripotent stem cells (iPSCs). Observed genomic variations reflect the combined activities of DNA damage, cellular DNA damage response (DDR), and selection pressure in culture. To understand the contribution of DDR on the distribution of copy number variations (CNVs) in iPSCs, we mapped CNVs of iPSCs with mutations in the central DDR gene ATM onto genome organization landscapes defined by genome-wide replication timing profiles. We show that following reprogramming the early and late replicating genome is differentially affected by CNVs in ATM deficient iPSCs relative to wild type iPSCs. Specifically, the early replicating regions had increased CNV losses during retroviral reprogramming. This differential CNV distribution was not present after later passage or after episomal reprogramming. Comparison of different reprogramming methods in the setting of defective DNA damage response reveals unique vulnerability of early replicating open chromatin to retroviral vectors.
Publication Title
Influence of ATM-Mediated DNA Damage Response on Genomic Variation in Human Induced Pluripotent Stem Cells.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2500
Description
Gamma-herpesviruses encode a cytoplasmic mRNA-targeting endonuclease, termed SOX, that cleaves the majority of mRNAs within a cell. Cleaved fragments are subsequently degraded by the cellular mRNA degradation machinery. Here, we reveal that mammalian cells respond to this widespread cytoplasmic mRNA decay by altering levels of RNA polymerase II (RNAPII) transcription in the nucleus. Measurements of both RNAPII recruitment to promoters and nascent mRNA synthesis revealed that the majority of affected genes are transcriptionally repressed in SOX-expressing cells. The transcriptional feedback does not occur in response to the initial endonuclease-induced cleavage, but instead to degradation of the cleaved fragments by cellular exonucleases. In particular, Xrn1 catalytic activity is required for transcriptional repression. Notably, viral mRNA transcription escapes decay-induced repression, and this escape requires Xrn1. Collectively, these results indicate that mRNA decay rates impact transcription in mammalian cells, and that gamma-herpesviruses have incorporated this feedback mechanism into their own gene expression strategy. Overall design: NIH 3T3 cells were mock, WT, or ?HS infected with MHV68 in duplicate and 4sU-labeled RNA isolated. 4sU-labeled RNA was submitted for sequencing and reads aligned to the mouse genome or MHV68 viral genome. Differential cellular gene expression was determined between mock and WT infected, mock and ?HS infected, as well as differential viral gene expression between WT and ?HS.
Publication Title
Viral Nucleases Induce an mRNA Degradation-Transcription Feedback Loop in Mammalian Cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 2 Downloadable Samples
- Illumina HiSeq 2000
Description
Transcriptome profiling using RNA-seq of ß-TC3 cell, a mouse pancreatic cell line used in the study of novel Cis-regulatory elements for the Pax6 gene . Overall design: Total RNA was collected and a Illumina sequencing libraries prepared from two biological replicates of cultured ß-TC3 cells.
Publication Title
Functional characteristics of novel pancreatic Pax6 regulatory elements.
Sample Metadata Fields
Cell line, Subject
View Samples- Rattus norvegicus
- 6 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
SHH signaling pathway is activated in many type of cancers. However, the role of its activation in particular type of cancer was poorly understood. The GLI family transcription factor GLI1 is the effector of Shh pathway activation and functions as oncogene. Our goal of research is to identify the GLI1 targets in desmoplastic medulloblastomas.
Publication Title
Defining a role for Sonic hedgehog pathway activation in desmoplastic medulloblastoma by identifying GLI1 target genes.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
Transcriptome profiling using RNA-seq of MV+, a mouse lens epithelium cell line expressing Pax6 and RAG renal adenocarcinoma cell line which does not express Pax6. Overall design: Total RNA was collected and a Illumina sequencing libraries prepared from three biological replicates of cultured MV+ and RAG cells.
Publication Title
Polymer Simulations of Heteromorphic Chromatin Predict the 3D Folding of Complex Genomic Loci.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Genome U95 Version 2 Array (hgu95av2)
Description
Considerable variation in gene expression data from different DNA microarray platforms has been demonstrated. However, no characterization of the source of variation arising from labeling protocols has been performed. To analyze the variation associated with T7-based RNA amplification/labeling methods, aliquots of the Stratagene Human Universal Reference RNA were labeled using 3 eukaryotic target preparation methods and hybridized to a single array type (Affymetrix U95Av2). Variability was measured in yield and size distribution of labeled products, as well as in the gene expression results. All methods showed a shift in cRNA size distribution, when compared to un-amplified mRNA, with a significant increase in short transcripts for methods with long IVT reactions. Intra-method reproducibility showed correlation coefficients >0.99, while inter-method comparisons showed coefficients ranging from 0.94 to 0.98 and a nearly two-fold increase in coefficient of variation. Fold amplification for each method was positively correlated with the number of present genes. Two factors that introduced significant bias in gene expression data were observed: a) number of labeled nucleotides that introduces sequence dependent bias, and b) the length of the IVT reaction that introduces a transcript size dependent bias. This study provides evidence of amplification method dependent biases in gene expression data.
Publication Title
In vitro transcription amplification and labeling methods contribute to the variability of gene expression profiling with DNA microarrays.
Sample Metadata Fields
No sample metadata fields
View Samples