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Arabidopsis thaliana
24 Downloadable Samples
Arabidopsis Gene 1.1 ST Array (aragene11st)
Description
Resistance against Verticillium longisporum is quantitative and multigenic. The vec1 QTL in Arabidopsis thaliana controlled resistance against systemic colonization by the fungus. Gene expression was studied to identify genes and pathways controlled by vec1. Near-isogenic lines derived from the resistant ecotype Bur and the susceptible ecotype Ler were compared. NIL9 contained Ler-alleles in the genomic region between 11753 and 12285 kb within vec1 on chromosome 2, tmNIL130 contained Bur-alleles. Microarrays were performed on samples containing the hypocotyl and the shoot basis because colonization is stopped in this region in resistant genotypes. Two developmental stages were studied: time-point (1) at the onset of flowering, when systemic colonization was shown to start and time point (2) at the onset of silique maturity, when extensive fungal proliferation was shown to occur. Two pathogen treatments were studied: (1) mock-inoculated controls, (2) plants inoculated with the V. longipsorum isolate 43 (VL).
Publication Title
No associated publication
Sample Metadata Fields
Time
View Samples- Homo sapiens
- 28 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Head and neck cancer is a hetergeneous disease. Based on previoulsy defined molecular subtypes we associated gene expression with response to different compounds. We used microarry gene expression for molecular subtyping
Publication Title
Basal subtype is predictive for response to cetuximab treatment in patient-derived xenografts of squamous cell head and neck cancer.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 20 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The methyl-cytosine binding protein 2 (MeCP2) is a reader of epigenetic DNA methylation marks and necessary and sufficient to reorganize 3D heterochromatin structure during cellular differentiation, e.g., myogenesis. In addition to global expression profile changes, myogenic differentiation is accompanied by 3D-heterochromatin reorganization that is dependent on MeCP2. MeCP2 is enriched at pericentric heterochromatin foci (chromocenters). During myogenesis, the total heterochromatin foci number per nucleus decreases while foci volumes and MeCP2 protein levels increase. Ectopic MeCP2 is able to mimic similar heterochromatin restructuring in the absence of differentiation.
Publication Title
Gene repositioning within the cell nucleus is not random and is determined by its genomic neighborhood.
Sample Metadata Fields
Specimen part, Cell line
View Samples
GSE83136- Arabidopsis thaliana
- 18 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Abiotic stress is a major factor for crop productivity, a problem likely to be exacerbated by climate change. Improving the tolerance to environmental stress is one of the most important goals of crop breeding programmes. While the early responses to abiotic stress in plants are well studied, plant adaptation to enduring or recurring stress conditions has received little attention. This project investigates the molecular mechanism of the maintenance of acquired thermotolerance as a model case of stress memory in Arabidopsis. Arabidopsis seedlings acquire thermotolerance through a heat treatment at sublethal temperatures. To investigate the underlying mechanisms, we are investigating changes in the transcriptome at two timepoints after a heat acclimation treatment using Arabidopsis thaliana seedlings.
Publication Title
Arabidopsis miR156 Regulates Tolerance to Recurring Environmental Stress through SPL Transcription Factors.
Sample Metadata Fields
Treatment
View Samples- Arabidopsis thaliana
- 9 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Transposable elements (TEs) make up a large proportion of eukaryotic genomes. As their mobilization creates genetic variation that threatens genome integrity, TEs are epigenetically silenced through several pathways and this may spread to neighboring sequences. JUMONJI (JMJ) proteins can function as anti-silencing factors and prevent silencing of genes next to TEs. Whether TE silencing is counterbalanced by the activity of anti-silencing factors is still unclear. Here, we characterize JMJ24 as a regulator of TE silencing. We show that loss of JMJ24 results in increased silencing of the DNA transposon AtMu1c, while overexpression of JMJ24 reduces silencing. JMJ24 has a JumonjiC (JmjC) domain and two RING domains. JMJ24 auto-ubiquitinates in vitro, demonstrating E3 ligase activity of the RING domain(s). JMJ24-JmjC binds the N-terminal tail of histone H3 and full-length JMJ24 binds histone H3 in vivo. JMJ24 activity is anti-correlated with histone H3 lysine 9 dimethylation (H3K9me2) levels at AtMu1c. Double mutant analyses with epigenetic silencing mutants suggest that JMJ24 antagonizes histone H3K9me2, and requires H3K9 methyltransferases for its activity on AtMu1c. Genome-wide transcriptome analysis indicates that JMJ24 affects silencing at additional TEs. Our results suggest that the JmjC domain of JMJ24 has lost demethylase activity but has been retained as a binding domain for histone H3. This is in line with phylogenetic analyses indicating that JMJ24 [with the mutated JmjC domain] is widely conserved in angiosperms. Taken together, this study assigns a role in TE silencing to a conserved JmjC-domain protein with E3 ligase activity, but no demethylase activity.
Publication Title
A JUMONJI Protein with E3 Ligase and Histone H3 Binding Activities Affects Transposon Silencing in Arabidopsis.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U219 Array (hgu219)
Description
We performed a comprehensive molecular and cellular analysis of primary dermal fibroblasts taken from a patient with recurrent cancers, harboring a BRCA1 mosaic epimutation (BRCA1mosMe) in comparison to their isogenic control fibroblasts (BRCA1wt), taken from the patients healthy monozygous sister.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part, Disease
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U219 Array (hgu219)
Description
Very small embryonic-like (VSEL) cells have been described as putatively pluripotent stem cells present in murine bone marrow and human umbilical cord blood (hUCB) and as such are of high potential interest for regenerative medicine. However, there remain some questions concerning the precise identity and properties of VSEL cells, particularly those derived from hUCB. For this reason, we have carried out an extensive characterisation of purified populations of VSEL cells from a large number of UCB samples. Consistent with a previous report, we find that VSEL cells are CXCR4+, have a high density, are indeed significantly smaller than HSC and have an extremely high nuclear/cytoplasmic ratio. Their nucleoplasm is unstructured and stains strongly with Hoechst 33342. A comprehensive FACS screen for surface markers characteristic of embryonic, mesenchymal, neuronal or hematopoietic stem cells revealed negligible expression on VSEL cells. These cells failed to expand in vitro under a wide range of culture conditions known to support embryonic or adult stem cell types and a microarray analysis revealed the transcriptional profile of VSELs to be clearly distinct both from well-defined populations of pluripotent and adult stem cells and from the mature hematopoietic lineages. Finally, we detected an aneuploid karyotype in the majority of purified VSEL cells by fluorescence in situ hybridisation. These data support neither an embryonic nor an adult stem cell like phenotype, suggesting rather that hUCB VSEL are an aberrant and inactive population that is not comparable to murine VSEL.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part
View Samples GSE5513- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Polyethylene glycol sorbitan monoacylates (Tween) are detergents of widespread use in plant sciences. We show them, notably Tween 20, to cause a rapid and complex change in transcript abundance which bears all characteristics of a PAMP / elicitor-induced defense response, and they do so at concentrations which cause no detectable deleterious effects on plant cellular integrity. The activity does not reside in the intact Tween molecule itself, but is caused by medium-chain fatty acids, notably lauric acid (LA), which are efficiently released from the Tween-backbone by the plant. The Tween / LA-response is independent of the jasmonate signalling system. Medium-chain fatty acids are thus novel elicitors/regulators of plant pathogen defense. The results also have several practical implications: (i) The use of Tweens and, as we show, several other detergents, as solvating/wetting agents on intact plants causes profound physiological changes which may mask actual effects of test compounds; (ii) Tweens by themselves can be regarded (and probably used) as economical, non-toxic, and safe-to-apply elicitors of inducible plant immunity against pathogens.
Publication Title
A novel regulatory system in plants involving medium-chain fatty acids.
Sample Metadata Fields
Age
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Mitogen-activated dual-specificity MAPK phosphatases are important negative regulators in the MAPK signalling pathways responsible for many essential processes in plants. In a screen for mutants with reduced organ size we have identified a mutation in the active site of the dual-specificity MAPK phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) that we named tinkerbell (tink) due to its small size. Analysis of the tink mutant indicates that IBR5 acts as a novel regulator of organ size that changes the rate of growth in petals and leaves. Organ size and shape regulation by IBR5 acts independently of the KLU growth-regulatory pathway. Microarray analysis of tink/ibr5-6 mutants identified a likely role for this phosphatase in male gametophyte development. We show that IBR5 may influence the size and shape of petals through auxin and TCP growth regulatory pathways.
Publication Title
The Tinkerbell (Tink) Mutation Identifies the Dual-Specificity MAPK Phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) as a Novel Regulator of Organ Size in Arabidopsis.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 68 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The aim of this study is to generate and validate biomarkers to stratify patients with Barretts esophagus in terms of risk for developing cancer. We studied gene expression profiling in 69 frozen specimens, consisting of esophageal squamous epithelium from 19 healthy subjects, 20 specimens from patients with Barretts esophagus and 21 cases of esophageal adenocarcinoma, 9 cased of esophageal squamous cell carcinoma by whole genome microarray analysis. Laser capture microdissection technique was applied to procure cells from defined regions of Barretts esophagus metaplasia and esophageal adenocarcinoma. Microarray results were validated by quantitative real-time polymerase chain reaction (qRT-PCR) in an independent cohort consisting of 42 cases. Furthermore, immunohistochemistry was performed using antibodies to two selected target molecules on a third independent cohort of 36 specimens, consisting of 36 cases. A total of 1176 genes were associated significantly with esophageal adenocarcinoma. The expression pattern of a 4 gene signature with the highest discriminant score based on linear discriminant analysis (GeneSpring GX10.2), was identified and validated by qRT-PCR in independent cohort.
Publication Title
Wdr66 is a novel marker for risk stratification and involved in epithelial-mesenchymal transition of esophageal squamous cell carcinoma.
Sample Metadata Fields
Specimen part
View Samples