The aim of this study was to determine the changes in gene expression of rice root tips when they came in to contact with a hard layer (60% wax layer). Three categories of root tips were sampled; tips before the hard layer, tips that had come into contact with the hard layer and root tips which had buckled after coming into contact with the hard layer.
A bioinformatic and transcriptomic approach to identifying positional candidate genes without fine mapping: an example using rice root-growth QTLs.
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View SamplesThe Mediator complex is an evolutionary conserved multiprotein complex that plays an essential role in initiating and regulating transcription. Its function is to act as a universal adaptor between RNA Polymerase II and DNA-bound transcription factors to translate regulatory information from activators and repressors to the transcriptional machinery. We have found that the PFT1 gene (which encodes the MED25 subunit of the Mediator complex) is required for the uncompromised expression of both salicylic acid- and jasmonate-dependent defense genes as well as resistance to the leaf-infecting fungal pathogens, Alternaria brassicicola and Botrytis cinerea in Arabidopsis. Surprisingly, we found that the pft1/med25 mutant showed increased resistance to the root infecting pathogen Fusarium oxysporum and that this resistance was independent of classical defense genes. In addition, the over-expression of PFT1 led to increased susceptibility to F. oxysporum. Therefore, to explore this phenomenon further, we wished to use whole genome transcript profiling to identify which genes may be playing a role in pft1/med25-mediated resistance to F. oxysporum.
The mediator complex subunit PFT1 is a key regulator of jasmonate-dependent defense in Arabidopsis.
Specimen part, Treatment
View SamplesRibosome assembly in eukaryotes involves the activity of hundreds of assembly factors that direct the hierarchical assembly of ribosomal proteins and numerous ribosomal RNA folding steps. However, detailed insights into the function of assembly factors and ribosomal RNA folding events are lacking. To address this, we have developed ChemModSeq, a method that combines structure probing, high throughput sequencing and statistical modeling, to quantitatively measure RNA structural rearrangements during the assembly of macromolecular complexes. By applying ChemModSeq to purified 40S assembly intermediates we obtained nucleotide-resolution maps of ribosomal RNA flexibility revealing structurally distinct assembly intermediates and mechanistic insights into assembly dynamics not readily observed in cryo-electron microscopy reconstructions. We show that RNA restructuring events coincide with the release of assembly factors and predict that completion of the head domain is required before the Rio1 kinase enters the assembly pathway. Collectively, our results suggest that 40S assembly factors regulate the timely incorporation of ribosomal proteins by delaying specific folding steps in the 3’ major domain of the 20S pre-ribosomal RNA. Overall design: Three datasets of yeast ribosomal samples subjected to different chemical modifications; 1M7 dataset contains 8 different modified samples and 2 control samples; NAI dataset contains 3 different modified samples and 2 control samples; DMS dataset contains 1 modified sample and 1 control sample. Each sample consists of at least two replicates.
Snapshots of pre-rRNA structural flexibility reveal eukaryotic 40S assembly dynamics at nucleotide resolution.
Disease, Cell line, Treatment, Subject
View SamplesAsthma is a heterogeneous disease. Exercise-induced bronchoconstriction (EIB) is a distinct syndrome that occurs in 30-50% of asthmatics and is characterized by high levels of pro-inflammatory eicosanoids. We identified genes differentially expressed in the airways of asthmatics with EIB relative to asthmatics without EIB. Genes related to epithelial repair and mast cell infiltration including beta-tryptase and carboxypeptidase A3 were upregulated by exercise challenge in the asthma group with EIB. We confirmed that two novel mediators trefoil factor 3 (TFF3) and transglutaminase 2 (TGM2) have increased expression in airways cells and secreted product in the airways. In vitro studies indicate that 1) TFF3 induces nitric oxide synthase in airway epithelial cells from asthmatics and 2) TGM2 augments the enzymatic activity of secreted phospholipase A2 (sPLA2) group X, an enzyme recently been implicated in asthma pathogenesis. Since PLA2 serves as the first rate-limiting step leading to eicosanoid generation, these results suggest that TGM2 may be a key initiator of the airway inflammatory cascade in asthma.
Transglutaminase 2, a novel regulator of eicosanoid production in asthma revealed by genome-wide expression profiling of distinct asthma phenotypes.
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View SamplesThe rate of RNA Polymerase II (RNAPII) elongation has an important role in the control of Alternative splicing (AS); however, the in vivo consequences of an altered elongation rate are unknown. Here, we generated mouse embryonic stem cells (ESCs) knocked-in for a slow elongating form of RNAPII. We show that a reduced transcriptional elongation rate results in early embryonic lethality in mice and impairs the differentiation of ESCs into the neural lineage. This is accompanied by changes in splicing and in gene expression in ESCs and along the pathway of neuronal differentiation. In particular, we found a crucial role for RNAPII elongation rate in transcription and splicing of long neuronal genes involved in synapse signaling. The impact of the kinetic coupling of RNAPII elongation rate with AS is more predominant in ESC-differentiated neurons than in pluripotent cells. Our results demonstrate the requirement for an appropriate transcriptional elongation rate to ensure proper gene expression and to regulate AS during development. Overall design: 4sURDB-Seq mouse wt and homozygous Polr2a[R749H] mutant embryonic stem cells in triplicates.
A slow transcription rate causes embryonic lethality and perturbs kinetic coupling of neuronal genes.
Treatment, Subject
View SamplesThe Wilms'' Tumour gene 1 (WT1), encodes for a complex protein with transcription factor activity which is essential in mammals throughout life. We provide a complete study of WT1 expression across different breast cancer subtypes as well as isoform specific expression analysis. Using in vitro cell lines, clinical samples and publicly available gene expression datasets, we demonstrate that WT1 plays a role in regulating the epithelial-mesenchymal balance of breast cancer cells and that WT1-expressing tumours are mainly associated with a mesenchymal phenotype. WT1 gene expression also correlates with CYP3A4 levels and is associated with poorer response to taxane treatment. Overall design: RNA profiles of breast cancer cells (MDA-MB-157) were generated by deep sequencing on the Illumina HiSeq 2000 platform. Untreated MDA-MB-157 cells, MDA-MB-157 cells transduced with a lacZ control vector, and MDA-MB-157 cells transduced with a lentiviral vector carrying a Wt1 shRNA were sequenced (titled untreated, lacZ and Wt1 respectively).
WT1 expression in breast cancer disrupts the epithelial/mesenchymal balance of tumour cells and correlates with the metabolic response to docetaxel.
No sample metadata fields
View SamplesPericytes derived from skin dermis can substantially enhance the short-term tissue-regenerative capacity of human epidermal cells already committed to differentiation; they also display both phenotypic and functional properties of mesenchymal stem cells. In this microarray analysis, we compared the gene expression profile of dermal pericytes to that of the remaining dermal cells of neonatal human foreskin.
A role for pericytes as microenvironmental regulators of human skin tissue regeneration.
Specimen part
View SamplesTh1 and Th2 cells arise from a common precursor cell in response to triggering through the TCR and cytokine receptors for IL-12 or IL-4. This leads to activation of complex signaling pathways, which are not known in detail. Disturbances in the balance between type 1 and type 2 responses can lead to certain immune-mediated diseases. Thus, it is important to understand how Th1 and Th2 cells are generated. To clarify the mechanisms as to how IL-12 and IL-4 induce Th1 and Th2 differentiation and how TGF-beta can inhibit this process, we have used oligonucleotide arrays to examine the early polarization of Th1 and Th2 cells in the presence and absence of TGF-beta after 0, 2, 6 and 48 hours of polarization.
Identification of novel genes regulated by IL-12, IL-4, or TGF-beta during the early polarization of CD4+ lymphocytes.
No sample metadata fields
View SamplesThe bovine chromaffin cell (BCC) is a unique modela highly homogeneous and accessible neuroendocrine cellin which to study gene regulation through first messenger-initiated signaling pathways that are specific to post-mitotic cells. BCCs were treated with tumor necrosis factor (TNF) or pituitary adenylate cyclase activating polypeptide (PACAP), two critical regulators of neural cell transcriptional programming during inflammation that act on TNFR2 and PAC1 receptors, respectively, in post-mitotic neuroendocrine cells. Transcripts which were significantly up regulated by either or both first messenger were identified from microarray analysis using two bovine oligonucleotide arrays (Affymetrix and Agilent) followed by statistical analysis with Partek Genomic suite. Microarray data were combined from the two arrays using qRT-PCR sampling validation, and the first-messenger transcriptome derived from TNF and PACAP signaling were compared. More than 90 percent of the genes up regulated either by TNF or PACAP were specific to a single first messenger. BioBase suite, DIRE and Opossum were used to identify common promoter/enhancer response elements that control the expression of TNF- or PACAP-stimulated genes. Bioinformatic analysis revealed that distinct groups of transcription factors control the expression of genes up regulated by either TNF or PACAP . Most of the genes up regulated by TNF contained response elements for members of the Rel transcription factor family, suggesting TNF-TNFR2 signaling mainly through the NF-kB signaling pathway. On the other hand, the PACAP regulated genes showed no enrichment for any single response element, containing instead response elements for combinations of transcription factors allowing activation through multiple signaling pathways, including cAMP, calcium and ERK, in neuroendocrine cells. Pharmacological strategies for mimicking neuroprotection by either PACAP or TNF in the context of CNS injury or degeneration in disease might focus on individual downstream gene activation pathways to achieve greater specificity in vivo.
Neuropeptides, growth factors, and cytokines: a cohort of informational molecules whose expression is up-regulated by the stress-associated slow transmitter PACAP in chromaffin cells.
Specimen part
View SamplesCharacterization of the underlying genetic defects in patients with a rare and peculiar phenotype is challenging. Here we have utilized whole genome expression profiling, and identified a homozygous germline mutation in the DDB2 gene in a patient with several facial tumors. The feasibility of using blood derived RNA, diminishing costs of the technology, and the limited number of samples needed provide this approach a powerful new tool that may substantially aid in such gene identification efforts.
Blood-derived gene-expression profiling in unravelling susceptibility to recessive disease.
No sample metadata fields
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