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GSE6167
Arabidopsis thaliana
6 Downloadable Samples
Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Our analysis of the sfr6 freezing-sensitive mutant (Knight, H., Veale, E., Warren, G. J. and Knight, M. R. (1999). Plant Cell 11, 875-886.) and cls8 (unpublished) chilling-sensitive mutant of Arabidopsis, has revealed that the expression of certain cold-regulated genes is aberrant in both these mutants. In order to understand the molecular basis of chilling and freezing stress in Arabidopsis and also to determine commonalities and differences between these 2 different physiological stress-tolerance processes, we request transcriptome analysis for both of these mutants compared to wild type in one experiment, upon cold treatment and at ambient conditions. The sfr6 mutant shows the most severe phenotype with respect to cold gene expression, but is tolerant to chilling (Knight, H., Veale, E., Warren, G. J. and Knight, M. R. (1999). Plant Cell 11, 875-886.). However, it is unable to cold acclimate and hence is sensitive to freezing. The cls8 mutant, on the other hand, has a relatively mild phenotype relative to the cold-regulated genes we have examined, but is very sensitive to chilling temperatures (15 to 10 degree centigrade). It is thus likely that in cls8 we have not yet identified the genes which are most affected, and which account for the physiological phenotype. Both sfr6 and cls8 have been fine-mapped and are close to being cloned. The cls8 mutant has an altered calcium signature in response to cold which means it is likely to be affected in early signalling, e.g. cold perception itself.We will compare the expression profiles of genes in sfr6, cls8 and Columbia (parental line for both mutants), both at ambient, and after treatment with cold (5 degrees) for 3 hours. This timepoint is designed to capture both rapidly responding genes e.g. CBF/DREB1 transcription factors, and also more slow genes e.g. COR genes (KIN1/2 and LTI78). Pilot northerns confirm that this time point is suitable.This analysis will provide new insight into 2 novel genes required for tolerance to low temperature in Arabidopsis, and additionally will determine the nature of overlap between the separate processes of chilling and freezing tolerance.
Publication Title
The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 4 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
The sfr6-1 mutant of Arabidopsis has been shown to be defective in freezing tolerance and fails to express a number of cold-regulated genes to normal wild type levels. The aim of this experiment was to test whether two other mutant alleles, sfr6-2 and sfr6-3 showed similar defects in cold-inducible gene expression.
Publication Title
The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.
Sample Metadata Fields
Age
View Samples- Mus musculus
- 36 Downloadable Samples
- Affymetrix Mouse Expression 430A Array (moe430a)
Description
Mouse embryonic fibroblasts (MEFs) were generated from 13.5-day-old embryos obtained from heterozygous PKBa mice intercrosses (Yang et al., 2003). Briefly, after dissection of head and visceral organs for genotyping, embryos were minced and trypsinized for 30 min at 37C. Embryonic fibroblasts were then plated and maintained in Dulbeccos Modified Eagle Medium (DMEM) with 10% foetal calf serum (FCS) (Life Technologies), 100 units/ml of penicillin and 100 mg/ml of streptomycin at 37C in an atmosphere of 5% CO2. All experiments were performed with wild-type and PKBa-/- MEFs between 15-20 passages. To induce adipocyte differentiation, 2-day-postconfluent cells (day 0) were treated with DMEM supplemented with 10% FCS, 8 mg/ml biotin, 4 mg/ml pantothenate, 0.5 mM 3-isobutyl-1-methylxanthine, 1 mM dexamethasone and 10 mg/ml insulin (all from Sigma). Total RNA was extracted from cells using TRIzol (Invitrogen) according to the manufacturers instructions.
Publication Title
PKBalpha is required for adipose differentiation of mouse embryonic fibroblasts.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 16 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The thymus constitutes the primary lymphoid organ for the majority of T cells. The phosphatidyl-inositol 3 kinase (PI3K) signaling pathway is involved in lymphoid development. Defects in single components of this pathway prevent thymocytes from progressing beyond early T cell developmental stages. Protein kinase B (PKB) is the main effector of the PI3K pathway. To determine whether PKB mediates PI3K signaling in early T cell development, we characterized PKB knockout thymi. Our results reveal a significant thymic hypocellularity in PKBalpha-/- neonates and an accumulation of early thymocyte subsets in PKBalpha-/- adult mice. The latter finding is specifically attributed to the lack of PKBalpha within the lymphoid component of the thymus. Microarray analyses show that the absence of PKBalpha in early thymocyte subsets modifies the expression of genes known to be involved in pre-TCR signaling, in T cell activation, and in the transduction of interferon-mediated signals. This report highlights the specific requirements of PKBalpha for thymic development.
Publication Title
Deletion of PKBalpha/Akt1 affects thymic development.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Glioblastoma multiforme (GBM) is the most malignant and most common tumor of the central nervous system characterized by rapid growth and extensive tissue infiltration. GBM results in more years of life lost than any other cancer type. Notch signaling has been implicated in GBM pathogenesis through several modes of action. Inhibition of Notch leads to a reduction of cancer-initiating cells in gliomas and reduces proliferation and migration. Deltex1 (DTX1) is part of an alternative Notch signaling pathway distinct from the canonical MAML1/RBPJ-mediated cascade. In this study, we show that DTX1 activates both the RTK/PI3K/PKB as well as the MAPK/ERK pathway. Moreover, we found the anti-apoptotic factor Mcl-1 to be induced by DTX1. In accordance with this, the clonogenic potential and proliferation rates of glioma cell lines correlated with DTX1 levels. DTX1 knock down mitigated the tumorigenic potential in vivo, and overexpression of DTX1 increased cell migration and invasion of tumor cells accompanied by an elevation of the pro-migratory factors PKB and Snail1. Microarray gene expression analysis identified a DTX1-specific transcriptional program - including microRNA-21 - which is distinct from the canonical Notch signaling. We propose the alternative Notch pathway via DTX1 as oncogenic factor in malignant glioma and found low DTX1 expression levels to correlate with prolonged survival of GBM and early breast cancer patients in open source databases.
Publication Title
Deltex-1 activates mitotic signaling and proliferation and increases the clonogenic and invasive potential of U373 and LN18 glioblastoma cells and correlates with patient survival.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 41 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
To identify signaling pathways that are differentially regulated in human gliomas, a microarray analysis on 30 brain tumor samples (12 primary glioblastomas (GBM), 3 secondary glioblastomas (GBM-2), 8 astrocytomas (Astro) and 7 oligodendrogliomas (Oligo)) and on 5 glioblastoma cell lines (LN018, LN215, LN229, LN319 and BS149) was performed. Normal brain tissue (NB) and normal human astrocytes (NHA) were used as a control. Kinase expression in each tumor was compared to expression in normal brain and expression values from normal human astrocytes were used as an additional control.
Publication Title
MAP kinase-interacting kinase 1 regulates SMAD2-dependent TGF-β signaling pathway in human glioblastoma.
Sample Metadata Fields
Sex, Age, Specimen part, Disease stage, Cell line
View Samples- Mus musculus
- 15 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Twist1 variants including wildtype Twist1, a non-phosphorylatable mutant Twist1/S42A and a phospho-mimicking mutant Twist1/S42D were expressed in 4T1 cells in which the endogenous Twist1 was depleted.
Publication Title
Akt/PKB-mediated phosphorylation of Twist1 promotes tumor metastasis via mediating cross-talk between PI3K/Akt and TGF-β signaling axes.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Genome U95 Version 2 Array (hgu95av2)
Description
Microarray-based studies of skeletal muscle from patients with type 2 diabetes and high-risk individuals have demonstrated that insulin resistance and reduced mitochondrial biogenesis co-exist early in the pathogenesis of type 2 diabetes independent of hyperglycaemia and obesity. It is unknown whether reduced mitochondrial biogenesis or other transcriptional alterations co-exist with impaired insulin-responsiveness in primary human muscle cells from patients with type 2 diabetes.
Publication Title
Transcriptional profiling of myotubes from patients with type 2 diabetes: no evidence for a primary defect in oxidative phosphorylation genes.
Sample Metadata Fields
No sample metadata fields
View Samples- Hordeum vulgare
- 6 Downloadable Samples
- Affymetrix Barley Genome Array (barley1)
Description
Comparison of wild type barley plants versus plants over-expressing ODDSOC2; a vernalization responsive MADS box gene ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Aaron Greenup. The equivalent experiment is BB93 at PLEXdb.]
Publication Title
ODDSOC2 is a MADS box floral repressor that is down-regulated by vernalization in temperate cereals.
Sample Metadata Fields
Specimen part
View Samples- Drosophila melanogaster
- 48 Downloadable Samples
NextSeq 500
Description
Obesity has been shown to increase risk for cardiovascular disease and type-2 diabetes. In addition, it has been implicated in aggravation of neurological conditions such as Alzheimer's. In the model organism Drosophila melanogaster, a physiological state mimicking diet-induced obesity can be induced by subjecting fruit flies to a solid medium disproportionately higher in sugar than protein (HSD) or that has been supplemented with a rich source of saturated fat (HFD). These flies can exhibit increased circulating glucose levels, increased triglyceride content, insulin-like peptide resistance, and behavior indicative of neurological decline, such as decreased climbing ability. We subjected Oregon-R-C flies to variants of the HSD, HFD, or normal (control) diet (ND), followed by a total RNA extraction from fly heads of each diet group for the purpose of Poly-A selected RNA-Sequencing. We targeted at least 50 million paired-end, stranded reads of 75 basepairs in size, and analyzed 4 biological replicates per dietary condition. Our objective was to identify the effects of obesogenic diets on transcriptome patterns, how they differed between obesogenic diets, and identify genes that may relate to pathogenesis accompanying an obesity-like state. Functional annotation and enrichment analysis among genes whose expression was significantly affected by the obesogenic diets indicated an overrepresentation of genes associated with immunity, metabolism, and hemocyanin in the HFD group, and CHK, cell cycle activity, and DNA binding and transcription in the HSD group. Heat map representation of genes affected by both diets illustrated a large fraction of differentially expressed genes between the two diet groups. Diets high in sugar and diets high in fat both have notableeffects on the Drosophila transcriptome in head tissue. The impacted genes, and how they may relate to pathogenesis in the Drosophila obesity-like state, warrant further experimental investigation. Our results also indicate differences in the effects of the HFD and HSD on expression profiles in head tissue of Oregon-R-C flies, despite the reportedly similar phenotypic impacts of the diets. Overall design: Flies were reared on one of three diets (high fat, high sugar, or normal). 6 replicates, with twenty flies each, from each diet treatment were collected for a total of 18 samples. The heads of the flies were then obtained, and RNA extracted from each of those samples. 4 of the RNA samples from each diet group (12 samples total) were sequenced.
Publication Title
RNA-Sequencing of <i>Drosophila melanogaster</i> Head Tissue on High-Sugar and High-Fat Diets.
Sample Metadata Fields
Specimen part, Subject
View Samples