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GSE23642
Xenopus laevis
18 Downloadable Samples
Affymetrix Xenopus laevis Genome 2.0 Array (xlaevis2)
Description
Recently a new neonatal diabetes syndrome, Mitchell-Riley syndrome, was discovered. To identify the genetic cause of the syndrome homozygosity mapping was used, several chromosomal regions were linked to Mitchell-Riley syndrome. In situ hybridization of genes from one such region using model organism Xenopus laevis identified RFX6 as a potential candidate gene; mutant forms of RFX6 were subsequently found in Mitchell-Riley patients. Analysis of the expression pattern of RFX6 in Xenopus development shows it is expressed broadly in the endoderm early in development, and later RFX6 becomes restricted to the endocrine cells of the gut and pancreas. Morpholino knockdown of RFX6 in Xenopus caused a loss of pancreas marker gene expression. Injection of exogenous wild type RFX6 rescued the morpholino phenotype in Xenopus tadpoles. Attempts to rescue the loss-of-function phenotype using mutant forms of RFX6 found in Mitchell-Riley patients were unsuccessful suggesting the changes lead to loss-of-function and could be the cause of Mitchell-Riley syndrome. Microarray analysis of gene expression in knockdown tissue suggested a downregulation in marker genes for lung, stomach and heart, ambiguous results for the liver, and an upregulation in kidney marker gene expression. RT-PCR and in situ hybridization confirms a loss of lung, stomach and heart gene expression, no change in liver marker hex and an upregulation in kidney marker KcnJ1. The fact that the morpholino phenotype affects multiple organs suggests that RFX6 has a broad role early in endoderm development.
Publication Title
Functional analysis of Rfx6 and mutant variants associated with neonatal diabetes.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Xenopus laevis
- 4 Downloadable Samples
- Affymetrix Xenopus laevis Genome Array (xenopuslaevis)
Description
During embryogenesis, the pancreas develops from separate dorsal and ventral buds, which fuse to form the mature pancreas. Little is known about the functional differences between these two buds or the relative contribution of cells derived from each portion to the pancreas after fusion. To follow the fate of dorsal or ventral bud derived cells in the pancreas after fusion, we produced chimeric Elas-GFP transgenic/wild type embryos in which either dorsal or ventral pancreatic bud cells expressed GFP. We found that ventral pancreatic cells migrate extensively into the dorsal pancreas after fusion, whereas the converse does not occur. Moreover, we found that annular pancreatic tissue is composed exclusively of ventral pancreas derived cells. To identify ventral pancreas specific genes that may play a role in pancreatic bud fusion, we isolated individual dorsal and ventral pancreatic buds, prior to fusion, from stage 38/39 Xenopus laevis tadpoles and compared their gene expression profiles. Morpholino-mediated knockdown of one of these ventral specific genes, transmembrane 4 superfamily member 3 (tm4sf3), inhibited dorsal-ventral pancreatic bud fusion as well as acinar cell differentiation. Conversely, overexpression of tm4sf3 promoted the development of annular pancreas. Our results are the first to define molecular and behavioral differences between the dorsal and ventral pancreas, and suggest an unexpected role for the ventral pancreas in pancreatic bud fusion.
Publication Title
The tetraspanin Tm4sf3 is localized to the ventral pancreas and regulates fusion of the dorsal and ventral pancreatic buds.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 35 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Pilocytic astrocytoma is the most common type of brain tumor in pediatric population, generally connected with favorable prognosis, although recurrences or dissemination sometimes are also observed. For tumors originating in supra- or infratentorial location different molecular background was suggested but plausible correlations between transcriptional profile and radiological features and/or clinical course are still undefined. The purpose of this study was to identify gene expression profiles related to the most frequent locations of this tumor, subtypes based on various radiological features and clinical pattern of the disease. According to the radiological features presented on MRI, all cases were divided into four subtypes: solid or mainly solid, cystic with an enhancing cyst wall, cystic with a non-enhancing cyst wall and solid with central necrosis. Bioinformatic analyses showed that gene expression profile of pilocytic astrocytoma highly depends on the tumor location. Most prominent differences were noted for IRX2, PAX3, CXCL14, LHX2, SIX6, CNTN1 and SIX1 genes expression which could distinguish pilocytic astrocytomas of different location even within supratentorial region. Analysis of the genes potentially associated between radiological features showed much weaker transcriptome differences. Single genes showed association with the tendency to progression. Here we showed that pilocytic astrocytomas of three different locations could be precisely differentiated on the basis of gene expression level but their transcriptional profiles did not strongly reflect the radiological appearance of the tumor or the course of the disease.
Publication Title
Transcriptional profiles of pilocytic astrocytoma are related to their three different locations, but not to radiological tumor features.
Sample Metadata Fields
Sex, Age, Specimen part, Disease
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
We have characterized a mutation affecting the Arabidopsis EARLY IN SHORT DAYS 7 (ESD7) gene encoding the catalytic subunit of the DNA polymerase epsilon (e), AtPOL2A. esd7-1 mutations causes early flowering independently of photoperiod, shortened inflorescence internodes and altered leaf and root development. esd7-1 was a hypomorphic allele whereas KO alleles displayed an embryo-lethal phenotype. The SAM and the RAM in the esd7-1 seedlings were found to exhibit an altered disposition that might correlate with the abnormal expression pattern of SAM and RAM marker genes. esd7-1 showed higher sensitivity to DNA damaging reagents than wild type plants and altered expression of genes involved in DNA repair mechanisms by homologous recombination. Moreover, esd7 early flowering phenotype requires functional FT and SOC1 proteins and might be also related to the mis-regulation of AG and AG-like gene expression found in esd7. Loci involved in the modulation of the chromatin structural dynamics, such as TFL2 and EBS, which negatively regulate FT expression, were found to interact genetically with ESD7, and the carboxy terminus of ESD7 interacted with TFL2 in vitro. Besides, fasciata2 (fas2) mutations suppressed esd7 early flowering phenotype and INCURVATA 2 (ICU2) was found to be epistatic to ESD7. Discrete regions of the chromatin of FT and AG loci were enriched in activating epigenetic marks in the esd7-1 mutant. We concluded that ESD7 might be participating in processes involved in chromatin-mediated cellular memory.
Publication Title
EARLY IN SHORT DAYS 7 (ESD7) encodes the catalytic subunit of DNA polymerase epsilon and is required for flowering repression through a mechanism involving epigenetic gene silencing.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 41 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
We have analyzed, using DNA microarrays, putative differences in gene-expression level between hereditary BRCA1 mutation-linked and sporadic breast cancer. Our results show that a previously reported marked difference between BRCA1-mutation linked and sporadic breast cancer was probably due to uneven stratification of samples with different ER status and basal-like versus luminal-like subtype. We observed that apparent difference between BRCA1-linked and other types of breast cancer found in univariate analysis was diminished when data were corrected for ER status and molecular subtype in multivariate analyses. In fact, the difference in gene expression pattern of BRCA1-mutated and sporadic cancer is very discrete. These conclusions were supported by the results of Q-PCR validation. We also found that BRCA1 gene inactivation due to promoter hypermethylation had similar effect on general gene expression profile as mutation-induced protein truncation. This suggests that in the molecular studies of hereditary breast cancer, BRCA1 gene methylation should be recognized and considered together with gene mutation.
Publication Title
BRCA1-related gene signature in breast cancer: the role of ER status and molecular type.
Sample Metadata Fields
Age
View Samples- Homo sapiens
- 17 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Molecular mechanisms of cell cycle exit are poorly understood. A group of genes required for cell cycle exit and maintenance of cell quiescence in human fibroblasts following serum deprivation has been recently identified. Studies on lymphocytes following growth factor deprivation-induced cell cycle exit have predominantly focused on the initiation of apoptosis. A set of genes involved in lymphocyte quiescence have also been identified among genes highly expressed in resting lymphocytes and down-regulated after cell activation. In our study, proliferating IL-2-dependent human T cells were forced to exit cell cycle by growth factor withdrawal, and their gene expression profiles were examined.
Publication Title
Molecular signature of cell cycle exit induced in human T lymphoblasts by IL-2 withdrawal.
Sample Metadata Fields
No sample metadata fields
View Samples- Arabidopsis thaliana
- 4 Downloadable Samples
Illumina HiSeq 2000
Description
We report the role of SmE1 protein in the control of Arabidopsis development and tolerance to abiotic stresses. SmE1 controls gene expression reprogramming at the post-transcriptional level by promoting the splicing of pre-mRNA. This function is selectively achieve over selected transcripts depending on the stimulus nature. Overall design: Transcriptomic profiling through RNAseq of Col-0 and sme1-1 plants under control conditions or exposed to low temperatures (4ºC, 24h)
Publication Title
Arabidopsis SME1 Regulates Plant Development and Response to Abiotic Stress by Determining Spliceosome Activity Specificity.
Sample Metadata Fields
Specimen part, Subject
View Samples- Saccharomyces cerevisiae
- 50 Downloadable Samples
- Illumina HiSeq 2500
Description
Transcriptome of S. cerevisiae in shifts between glucose and maltose media with different re-growth conditions Overall design: Cells are pregrown in maltose, then grown for different durations in glucose and then washed back to maltose
Publication Title
A new protocol for single-cell RNA-seq reveals stochastic gene expression during lag phase in budding yeast.
Sample Metadata Fields
Subject
View Samples- Mus musculus
- 30 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The chemokine decoy receptor D6 internalises and degrades inflammatory CC chemokines enabling resolution of inflammation. In D6 deficient mice (D6 KO), otherwise innocuous cutaneous inflammatory stimuli induce a grossly exaggerated inflammatory response that bears many similarities to human psoriasis. In the present study we have used transcriptomic approaches to define the molecular make up of this response.
Publication Title
Microarray analyses demonstrate the involvement of type I interferons in psoriasiform pathology development in D6-deficient mice.
Sample Metadata Fields
Sex, Specimen part, Treatment, Time
View Samples- Homo sapiens
- 99 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The introduction of microarray techniques to cancer research brought great expectations for finding biomarkers that would improve patients treatment; however, the results of such studies are poorly reproducible and critical analyses of these methods are rare. In this study, we examined global gene expression in 97 ovarian cancer samples. Also, validation of results by quantitative RT-PCR was performed on 30 additional ovarian cancer samples. We carried out a number of systematic analyses in relation to several defined clinicopathological features. The main goal of our study was to delineate the molecular background of ovarian cancer chemoresistance and find biomarkers suitable for prediction of patients prognosis. We found that histological tumor type was the major source of variability in genes expression, except for serous and undifferentiated tumors that showed nearly identical profiles. Analysis of clinical endpoints [tumor response to chemotherapy, overall survival, disease-free survival (DFS)] brought results that were not confirmed by validation either on the same group or on the independent group of patients. CLASP1 was the only gene that was found to be important for DFS in the independent group, whereas in the preceding experiments it showed associations with other clinical endpoints and with BRCA1 gene mutation; thus, it may be worthy of further testing. Our results confirm that histological tumor type may be a strong confounding factor and we conclude that gene expression studies of ovarian carcinomas should be performed on histologically homogeneous groups. Among the reasons of poor reproducibility of statistical results may be the fact that despite relatively large patients group, in some analyses one has to compare small and unequal classes of samples. In addition, arbitrarily performed division of samples into classes compared may not always reflect their true biological diversity. And finally, we think that clinical endpoints of the tumor probably depend on subtle changes in many and, possibly, alternative molecular pathways, and such changes may be difficult to demonstrate.
Publication Title
Gene expression analysis in ovarian cancer - faults and hints from DNA microarray study.
Sample Metadata Fields
No sample metadata fields
View Samples