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GSE22207
Escherichia coli str. k-12 substr. mg1655
4 Downloadable Samples
Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
Promoter recognition by bacterial RNA polymerase is mediated by subunits, which assemble transiently to RNA polymerase core enzyme (E) during transcription initiation. subunits drive transcription of specific sets of genes by allowing RNA polymerase to interact with different promoter sequences. However, 70, the housekeeping subunit, and S, an alternative subunit mainly active during slow growth and in response to cellular stresses, appear to recognize almost identical promoter sequences, raising the question of how promoter selectivity is achieved in the bacterial cell. To identify sequence determinants for selective promoter recognition, we performed a run-off/microarray experiment (ROMA): in vitro transcription experiments were carried out with RNA polymerase saturated either with 70 (E70) or with S (ES) using the whole Escherichia coli genome as DNA template, and transcript levels were determined by microarray analysis. We found that several genes associated with bacterial growth (e.g., ribosomal operons) were transcribed more efficiently by E70. In contrast, ES transcribed preferentially genes involved in stress responses, secondary metabolism, as well as regulatory RNAs and intergenic regions with yet unknown function. Genes preferentially recognized in vitro by ES showed reduced expression in ES -deficient mutant strain of E. coli. Sequence comparison of E70- versus ES dependent promoters confirms that the presence of a -35 sequence and the relative location of UP elements affect promoter interaction with either form of RNA polymerase, and suggests that a G/C bias in the -2/+1 nucleotides would favour efficient promoter recognition by E70.
Publication Title
In vitro transcription profiling of the σS subunit of bacterial RNA polymerase: re-definition of the σS regulon and identification of σS-specific promoter sequence elements.
Sample Metadata Fields
Disease
View Samples- Homo sapiens, Rattus norvegicus
- 98 Downloadable Samples
- Affymetrix Rat Expression 230A Array (rae230a)
Description
Background. Vaginal atrophy (VA) is the thinning of the vaginal epithelial lining, typically the result of lowered estrogen levels during menopause. Some of the consequences of VA include increased susceptibility to bacterial infection, pain during sexual intercourse, and vaginal burning or itching. Although estrogen treatment is highly effective, alternative therapies are also desired for women who are not candidates for hormone replacement therapy (HRT). The ovariectomized (OVX) rat is widely accepted as an appropriate animal model for many estrogen-dependent responses in humans; however, since reproductive biology can vary significantly between mammalian systems, this study examined how well the OVX rat recapitulates human biology at the transcriptional level. This report describes an analysis of expression profiling data, comparing the responses of rat and human vaginae to estrogen treatment. Results. The level of differential expression between pre- vs. post- estrogen treatment was calculated for each of the human and OVX rat datasets. Probe sets corresponding to orthologous rat and human genes were mapped to each other using NCBI Homologene. A positive correlation was observed between the rat and human responses to estrogen. Genes belonging to several biological pathways and GO categories were similarly differentially expressed in rat and human. A large number of the coordinately regulated biological processes are already known to be involved in human VA, such as inflammation, epithelial development, and EGF pathway activation. Conclusions. At the transcriptional level, there is evidence of significant overlap of the effects of estrogen treatment between the OVX rat and human VA samples.
Publication Title
Molecular analysis of the vaginal response to estrogens in the ovariectomized rat and postmenopausal woman.
Sample Metadata Fields
Age
View Samples- Homo sapiens
- 6 Downloadable Samples
Illumina Genome Analyzer IIx
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Dynamic Transcriptional and Epigenetic Regulation of Human Epidermal Keratinocyte Differentiation.
Sample Metadata Fields
Specimen part, Disease
View Samples- Homo sapiens
- 6 Downloadable Samples
- NextSeq500
Description
Transcriptional profiling of KP and DK through RNA-seq Overall design: RNA-sequencing of KP and DK
Publication Title
Dynamic Transcriptional and Epigenetic Regulation of Human Epidermal Keratinocyte Differentiation.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 6 Downloadable Samples
Illumina Genome Analyzer IIx
Description
Gene expression profiling of progenitor and differentiated keratinocytes by Affymetrix microarray
Publication Title
Dynamic Transcriptional and Epigenetic Regulation of Human Epidermal Keratinocyte Differentiation.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 1 Downloadable Sample
- IlluminaGenomeAnalyzerIIx
Description
Investigation of promoters usage in KP cells Overall design: KP cells promoter usage profiling by CAGE-seq
Publication Title
Dynamic Transcriptional and Epigenetic Regulation of Human Epidermal Keratinocyte Differentiation.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 3 Downloadable Samples
- UNKNOWN
Description
Evaluation of two commercial microarray platforms (Amersham CodeLink UniSet Human 10K I BioArray and Affymetrix GeneChip HG-U133A). Both platforms have been tested on gene expression profiling of MDA-MB-231 human metastatic breast cancer cells, cultured for 48 h in the absence (control) or presence (treated) of 32 µM resveratrol.
Publication Title
Strategies for comparing gene expression profiles from different microarray platforms: application to a case-control experiment.
Sample Metadata Fields
Sex, Specimen part, Disease, Disease stage, Cell line, Compound
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2), Illumina Genome Analyzer IIx
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Genome-Wide Definition of Promoter and Enhancer Usage during Neural Induction of Human Embryonic Stem Cells.
Sample Metadata Fields
Specimen part, Disease
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Genome-wide mapping of transcriptional regulatory elements are essential tools for the understanding of the molecular events orchestrating self-renewal, commitment and differentiation of stem cells. We combined high-throughput identification of nascent, Pol-II-transcribed RNAs by Cap Analysis of Gene Expression (CAGE-Seq) with genome-wide profiling of histones modifications by chromatin immunoprecipitation (ChIP-seq) to map active promoters and enhancers in a model of human neural commitment, represented by embryonic stem cells (ESCs) induced to differentiate into self-renewing neuroepithelial-like stem cells (NESC). We integrated CAGE-seq, ChIP-seq and gene expression profiles to discover shared or cell-specific regulatory elements, transcription start sites and transcripts associated to the transition from pluripotent to neural-restricted stem cell. Our analysis showed that >90% of the promoters are in common between the two cell types, while approximately half of the enhancers are cell-specific and account for most of the epigenetic changes occurring during neural induction, and most likely for the modulation of the promoters to generate cell-specific gene expression programs. Interestingly, the majority of the promoters activated or up-regulated during neural induction have a bivalent histone modification signature in ESCs, suggesting that developmentally-regulated promoters are already poised for transcription in ESCs, which are apparently pre-committed to neuroectodermal differentiation. Overall, our study provide a collection of differentially used enhancers, promoters, transcription starts sites, protein-coding and non-coding RNAs in human ESCs and ESC-derived NESCs, and a broad, genome-wide description of promoter and enhancer usage and gene expression programs occurring in the transition from a pluripotent to a neural-restricted cell fate.
Publication Title
Genome-Wide Definition of Promoter and Enhancer Usage during Neural Induction of Human Embryonic Stem Cells.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 2 Downloadable Samples
- IlluminaGenomeAnalyzerIIx
Description
Genome-wide mapping of transcriptional regulatory elements are essential tools for the understanding of the molecular events orchestrating self-renewal, commitment and differentiation of stem cells. We combined high-throughput identification of nascent, Pol-II-transcribed RNAs by Cap Analysis of Gene Expression (CAGE-Seq) with genome-wide profiling of histones modifications by chromatin immunoprecipitation (ChIP-seq) to map active promoters and enhancers in a model of human neural commitment, represented by embryonic stem cells (ESCs) induced to differentiate into self-renewing neuroepithelial-like stem cells (NESC). We integrated CAGE-seq, ChIP-seq and gene expression profiles to discover shared or cell-specific regulatory elements, transcription start sites and transcripts associated to the transition from pluripotent to neural-restricted stem cell. Our analysis showed that >90% of the promoters are in common between the two cell types, while approximately half of the enhancers are cell-specific and account for most of the epigenetic changes occurring during neural induction, and most likely for the modulation of the promoters to generate cell-specific gene expression programs. Interestingly, the majority of the promoters activated or up-regulated during neural induction have a “bivalent” histone modification signature in ESCs, suggesting that developmentally-regulated promoters are already poised for transcription in ESCs, which are apparently pre-committed to neuroectodermal differentiation. Overall, our study provide a collection of differentially used enhancers, promoters, transcription starts sites, protein-coding and non-coding RNAs in human ESCs and ESC-derived NESCs, and a broad, genome-wide description of promoter and enhancer usage and gene expression programs occurring in the transition from a pluripotent to a neural-restricted cell fate. Investiagtion of promoters usage changes during ESCs neural induction Overall design: ESCs and NESCs promoter usage profiling by CAGE-seq
Publication Title
Genome-Wide Definition of Promoter and Enhancer Usage during Neural Induction of Human Embryonic Stem Cells.
Sample Metadata Fields
No sample metadata fields
View Samples