ChIP-sequencing analysis of Myc binding sites 4 hours after Myc activation in liver and heart tissue, from wild type and R26CAG-c-MycERT2 mice
Ontology highlight
ABSTRACT: Aim: To determine Myc binding sites in mouse heart and liver, 4 hours post MycER activation. c-Myc ChIP sequencing performed on chromatin isolated from hearts and livers harvested from wild-type (R26+/+) and R26CAG-c-MycERT2/+ mice 4 hours post administration of (Z)-4-hydroxytamoxifen.
Project description:Aim: To determine RNA Pol II binding sites in mouse heart and liver, 4 hours post MycER activation. Pol II ChIP sequencing performed on chromatin isolated from hearts and livers harvested from wild-type (R26+/+) and R26CAG-c-MycERT2/+ mice 4 hours post administration of (Z)-4-hydroxytamoxifen.
Project description:Polycomb group (PcG) proteins are required for normal differentiation and development, and their activity is found deregulated in cancer. PcG proteins are involved in gene silencing, however, whether they initiate or maintain transcriptional repression is a subject of debate. Here, we show that knockout of the Polycomb repressive complex 2 (PRC2) does not lead to significant gene expression changes in mouse embryonic stem cells (mESCs), and that it is dispensable for initiating silencing of target genes during differentiation. Transcriptional inhibition in mESCs is sufficient to induce genome-wide ectopic PRC2 recruitment to endogenous PcG target genes found in other tissues. PRC2 binding analysis shows that it is restricted to nucleosome-free CpG islands (CGIs) of un-transcribed genes. Our results show that it is the transcriptional state that governs PRC2 binding, and we propose that it binds by default to non-transcribed CGI genes to maintain their silenced state and to protect cell identity. Input from ChIP-seq experiment in Mus musculus wild-type E14 Embryonic Stem Cells.
Project description:Polycomb group (PcG) proteins are required for normal differentiation and development, and their activity is found deregulated in cancer. PcG proteins are involved in gene silencing, however, whether they initiate or maintain transcriptional repression is a subject of debate. Here, we show that knockout of the Polycomb repressive complex 2 (PRC2) does not lead to significant gene expression changes in mouse embryonic stem cells (mESCs), and that it is dispensable for initiating silencing of target genes during differentiation. Transcriptional inhibition in mESCs is sufficient to induce genome-wide ectopic PRC2 recruitment to endogenous PcG target genes found in other tissues. PRC2 binding analysis shows that it is restricted to nucleosome-free CpG islands (CGIs) of un-transcribed genes. Our results show that it is the transcriptional state that governs PRC2 binding, and we propose that it binds by default to non-transcribed CGI genes to maintain their silenced state and to protect cell identity. Suz12, H3K27me3 and RNAPII ChIP-seq experiments before and after transcriptional inhibition with either DRB (0h, 6h and 12h) or Triptolide (0h, 3h and 9h) treatment of Mus musculus wild-type E14 Embryonic Stem Cells with up to two biological replicates per condition.
Project description:Our work describes novel roles for EZH2 in the specification of cortical neurons. Previous reports established the current model of EZH2-mediated control of neuronal progenitors differentiation through the regulation of their proliferation and developmental transitions. We built on these findings and studied the role of EZH2 in post-mitotic glutamatergic neurons differentiated from embryonic stem cells, a particularly relevant cell type where the impact of its regulation has thus far remained elusive. Briefly, our key results can be summarized as follows: 1. The conditional deletion of EZH2 at the moment of cell cycle exit in neural progenitors allowed us to study the role of EZH2 selectively in post-mitotic glutamatergic neurons. 2. Time course transcriptomic and epigenomic analyses of H3K27me3 in absence of EZH2 revealed a significant dysregulation of transcriptional networks affecting synaptic plasticity, in particular long term depression. 3. These analyses also revealed potential novel roles of EZH2 in controlling the regulation between the glutamatergic signature and the GABAergic one, suggesting a mechanism entailing failure of Prdm13 repression, a histone methyltransferase with a known role in determining GABAergic neurons specification.
Project description:DNA methylation is tightly regulated throughout mammalian development and altered methylation patterns are a hallmark of cancer. The methylcytosine dioxygenase TET2 is frequently mutated in acute myeloid leukemia (AML) and has been suggested to protect CpG islands and promoters from aberrant methylation. By generating a novel mouse model of Tet2-deficient AML we show that loss of Tet2 in hematopoietic cells leads to progressive hypermethylation of active enhancer elements and altered expression of genes implicated in tumorigenesis. In contrast, CpG island and promoter methylation does not change in a Tet2-dependent manner. Furthermore, we confirm this specific enhancer hypermethylation phenotype in human AML patients. Thus, we propose that TET2 prevents leukemic transformation of hematopoietic cells by protecting enhancers from aberrant DNA methylation. ChIP-seq analysis for distribution of H3K4me1, H3K27ac, and H3K4me3 histone marks in in vitro-grown hematopoietic cells transduced with AML1-ETO
Project description:The G-quadruplex is an alternative DNA structural motif that is considered to be functionally important in the mammalian genome. Herein, we address the hypothesis that G-quadruplex structures can exist within double-stranded genomic DNA using a G-quadruplex-specific probe. An engineered antibody is employed to enrich for DNA containing G-quadruplex structures, followed by deep sequencing to detect and map G-quadruplexes at high resolution in genomic DNA from human breast adenocarcinoma cells. Our high sensitivity structure-based pull-down strategy enables the isolation of genomic DNA fragments bearing a single as well as multiple G-quadruplex structures. Stable G-quadruplex structures are found in sub-telomeres, gene bodies and gene regulatory regions. For a sample of identified target genes, we show that G-quadruplex stabilizing ligands can modulate transcription. These results confirm the existence of G-quadruplex structures and their persistence in human genomic DNA. Four independent libraries have been enriched in DNA G-quadruplex structures using a G-quadruplex-specific probe. One genomic input library was sequenced as control. Deep-sequencing of these libraries allowed the mapping of G-quadruplexes on the genome.
Project description:In mouse embryonic stem cells SNPs disrupting closely-spaced hexanucleotide motifs are associated with lack of ZFP57 binding and H3K9me3 enrichment. Examination of ZFP57-KAP1 allele-specific binding in two lines of mouse embryonic stem cells JB1 and BJ1 generated from F1 hybrids derived from JF1 x B6 and B6 x JF1 crosses respectively.
Project description:The WalKR regulon was studied by comparing genes expression in a strain producing a constitutively active WalR regulator (WalRc) versus the wild type strain carrying the empty expression vector. Hybridizations were performed with three independent biological replicates. Our data allowed to identify 165 genes differentially expressed in the walRc expressing strain with a P-value M-bM-^IM-$ 0.05 using Z-test and a threshold value of two-fold change in transcriptional levels. Among them, 108 genes are activated, and 57 genes are repressed. About 10% of these results were confirmed by quantitative real time PCR, revealing the high reliability of this overall study. Beyond the major effect of the WalKR system on genes expressing cell wall hydrolases, we have shown that it activates a large number of genes involved in virulence, and probably through its positive impact on the SaeRS two-component system, is a major activator of S. aureus virulence. Cells were grown in TSB rich medium added with 0.25 M-BM-5M CdCl2 to allow walRc expression until OD600nm of 1. Gene expression was compared between the HG001 wild type reference strain carrying the pCN51 empty vector (HG001/pCN51) and the HG001 strain carrying a pCN51 derivative with the walRc allele under the control of the Pcad inducible promoter (HG001/pSD3-12). Each condition was done in triplicate and the data were analyzed using the Arraystat software. Genes were considered as differentially expressed if their transcriptional level differed by at least two-fold with a Z-test P-value M-bM-^IM-$ 0.05 in at least two of the replicates.
Project description:To determine the genome-wide pattern of H3K27ac in IMR90 (ATCC CCL-186) cells we performed ChIP-seq upon hormone treatment (1.5 h, 1 M dexamethasone).
Project description:Through high throughput compound screening, we've identified compounds that induce the expression of fetal hemoglobin. This study contains CUT&RUN data of a novel target, WIZ.