The analysis of several mammalian genomes has revealed between 20,000 to 30,000 genes in each genome, a number that may seem hard to reconcile with the large number of cell types and complex functions of these organisms. The solution to this paradox partly lies in the large array of transcripts that each gene can potentially generate through usage of alternative promoters and the variable levels of transcripts that each gene produces in different tissues and cell types. Thus, in order to understand the mechanisms that control diverse patterns of gene expression in mammals, it is necessary to accurately define the active promoters and monitor their cell or tissue-dependent activity. Previous high throughput strategies for assaying tissue-specific gene expression have primarily relied on measurements of steady-state transcript levels by microarrays or tag sequencing. Here, we employ a new experimental strategy to identify and characterize tissue specific promoters by integrating genome-wide maps of RNA polymerase II (Pol II) binding, chromatin modifications and gene expression profiles. We applied this strategy to mouse embryonic stem cells (mES), and adult brain, heart, kidney, and liver. Our results delineated 24,363 Pol II binding sites throughout the genome, 91% of which correspond to 5 end annotation based on known transcripts and cap-analysis of gene expression (CAGE) and can be regarded as promoters. A majority of these experimentally defined promoters are active in all tissues, while only 4,396 can be characterized as tissue-specific using a quantitative measure of Pol II occupancy. In general, Pol II occupancy at these tissue specific promoters is correlated with the presence of active histone modification marks. However, a set of mES- specific promoters display persistent levels of H3K4me3 in non-ES tissues despite undetectable Pol II binding and transcript. Broadly, our results expand the knowledge of tissue-specific mammalian genes and provide a resource for understanding the transcriptional programs in mammalian development and differentiation.
Genome-wide mapping and analysis of active promoters in mouse embryonic stem cells and adult organs.
No sample metadata fields
View SamplesThe role of Striatin Interacting Protein 2 (Strip2) in differentiation of embryonic stem cells (ESCs) is still under debate. Strip2 silenced (KD) ESCs were differentiated for 4, 8, 12, and 16 days. We show that Strip2 is distributed in the perinucleus or nuclei of wild type (WT) undifferentiated ESCs, but is localized in high-density nuclear bodies in differentiated cells. CellNet analysis of microarray gene expression data for KD and scrambled control (SCR) embryoid bodies (EBs), as well as immunostainings of key pluripotent factors, demonstrated that KD ESCs remain undifferentiated. This occurs even in 16-day old EBs, which possessed a high tumorigenic potential. Correlated with very high expression levels of epigenetic regulator genes, Hat1 and Dnmt3, enzymatic activities of the histone acetyltransferase type B (HAT1) and DNA (cytosine-5)-methyltransferase 3 beta (DNMT3b) were higher in differentiated 16-day old KD EBs than in SCR or WT EBs. The expression levels of let-7, 290 and 302 microRNA families were opposed in KD ESCs, while KD EBs had levels comparable to WT and SCR ESCs during differentiation. This demonstrates that Strip2 is critical to the onset of differentiation, regulating expression of epigenetic regulators, HAT1 and DNMT3b, as well as microRNAs involved in pluripotency.
STRIP2 Is Indispensable for the Onset of Embryonic Stem Cell Differentiation.
Sex, Specimen part
View SamplesPolycomb repressive complex 2 (PRC2-EZH2) methylates histone H3 at lysine 27 (H3K27) and is required to maintain gene repression during development. Misregulation of PRC2 is linked to a range of neoplastic malignancies, which is believed to involve methylation of H3K27. However, the full spectrum of non-histone substrates of PRC2 that might also contribute to PRC2 function is not known. We characterized the target recognition specificity of PRC2 and used the resultant data to screen for novel potential targets. The RNA polymerase II (Pol II) transcription factor, Elongin A (EloA), is methylated by PRC2 in vivo. Mutation of the methylated EloA residue decreased repression of many, but not all, PRC2 target genes as measured by both steady state and nascent RNA levels. We propose that PRC2 regulates transcription of a subset of target genes in part via methylation of EloA. Overall design: We examined the transcripitonal profile of EEDnull, EloAnull, EloA mutant, and parental mouse embryonic stem cells by RNAseq. Please note that the .bw processed data file was generated from the *mESC replicate samples together and linked to the corresponding *rep1 sample records.
Polycomb Repressive Complex 2 Methylates Elongin A to Regulate Transcription.
Specimen part, Subject
View SamplesPolycomb repressive complex 2 (PRC2-EZH2) methylates histone H3 at lysine 27 (H3K27) and is required to maintain gene repression during development. Misregulation of PRC2 is linked to a range of neoplastic malignancies, which is believed to involve methylation of H3K27. However, the full spectrum of non-histone substrates of PRC2 that might also contribute to PRC2 function is not known. We characterized the target recognition specificity of PRC2 and used the resultant data to screen for novel potential targets. The RNA polymerase II (Pol II) transcription factor, Elongin A (EloA), is methylated by PRC2 in vivo. Mutation of the methylated EloA residue decreased repression of many, but not all, PRC2 target genes as measured by both steady state and nascent RNA levels. We propose that PRC2 regulates transcription of a subset of target genes in part via methylation of EloA. Overall design: We examined the nascent transcripiton profile of mES cells by adding 5-Bromouridine (BrU) to the media for 10 min. Following RNA isolation, BrU-labelled nascent RNA species were affinity purified using BrdU antibody and sequenced after library preparation. Please note that each .bw file was generated from two replicate samples together and linked to the corresponding *rep1 sample records.
Polycomb Repressive Complex 2 Methylates Elongin A to Regulate Transcription.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative genomic analysis of the human immune response to influenza vaccination.
Sex, Specimen part, Treatment, Subject, Time
View SamplesThe purpose of the study was to assess the patterns of global gene expression in peripheral blood cells before and at three time points after the administration of a trivalent influenza vaccine in human male subjects, and to relate these to the antibody response to the vaccine. The antibody titer data for these subjects is provided as a supplemental file.
Integrative genomic analysis of the human immune response to influenza vaccination.
Sex, Specimen part, Treatment, Subject, Time
View SamplesThe purpose of the study was to assess the patterns of global gene expression in peripheral blood cells before and at three time points after the administration of a trivalent influenza vaccine in human female subjects, and to relate these to the antibody response to the vaccine
Integrative genomic analysis of the human immune response to influenza vaccination.
Sex, Specimen part, Treatment, Subject, Time
View SamplesHuman prostate cancer tissues analyses
In silico dissection of cell-type-associated patterns of gene expression in prostate cancer.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
CD13 and ROR2 Permit Isolation of Highly Enriched Cardiac Mesoderm from Differentiating Human Embryonic Stem Cells.
Specimen part, Cell line
View SamplesThe resultant heat map demonstrates the maturation of CD13+/ROR2+ cells as they proceed through cardiac differentiation. Overall design: RNA-seq analysis was preformed on RNA samples from undifferentiated hESCs, 13R2+ and 13R2- populations from day 3, 13R2+/NKX2-5+ and 13R2+/NKX2-5- from day 7, and 13R2+/NKX2-5+/a-MHC+ and 13R2+/NKX2-5+/MHC- from day 14
CD13 and ROR2 Permit Isolation of Highly Enriched Cardiac Mesoderm from Differentiating Human Embryonic Stem Cells.
No sample metadata fields
View Samples