Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Transcriptional dynamics of paternal X chromosome reveals different epigenetic memory of the inactive state in the inner cell mass

ABSTRACT: This study concerns the dynamics of reprogramming of the inactive X chromosome in the inner cell mass of the E3.5-4.5 mouse blastocysts. We use single cell, allele-specific transcriptomic analyses to define the precise timing of paternal X-linked gene reactivation, as well as nascent RNA FISH and immunuofluorescence to follow the loss of chromatin marks such as H3K27me3. We find evidence that different genes show very different timing of reactivation indicating an epigenetic memory of the inactive state in some cases but not in others. In exploring whether PRC2 might be part of this memory we uncover a role for the X-linked histone demethylase Utx (a gene that actually escapes XCI), in the efficiency of H3K27me3 erasure and reactivation of of the paternal X. This work describes the precise timing and potential mechanisms of X-chromosome reactivation in vivo for the first time.

ORGANISM(S): Mus musculus

PROVIDER: GSE89900 | GEO | 2017/09/08

SECONDARY ACCESSION(S): PRJNA354277

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Dynamic Erasure of Random X-Chromosome Inactivation during iPSC Reprogramming

Project description:Induction and reversal of chromatin silencing is critical for successful development, tissue homeostasis and the derivation of induced pluripotent stem cells (iPSCs). X-chromosome inactivation (XCI) and reactivation (XCR) in female cells represent chromosome-wide transitions between active and inactive chromatin states. While XCI has long been studied and provided important insights into gene regulation, the dynamics and mechanisms underlying the reversal of stable chromatin silencing of X-linked genes are much less understood. In this work, we use allele-resolution transcriptomic approaches to study XCR during mouse iPSC reprogramming in order to elucidate the timing and mechanisms of chromosome-wide reversal of gene silencing. Our findings reveal a sequential hierarchy of gene reactivation from the inactive X-chromosome (Xi). We show that gene reactivation initiates before the activation of late pluripotency genes and complete silencing of the long non-coding RNA (lncRNA) Xist, and is completed late in reprogramming. We reveal that the gene-specific timing of reactivation correlates with the genomic distance to genes that escape inactivation and with differential targeting by pluripotency transcription factors (TFs). We also show that histone deacetylases restrict XCR in reprogramming intermediates and that the severe hypoacetylation state of the Xi persists until late reprogramming stages. Therefore, randomly inactivated X-linked genes possess different degrees of epigenetic memory, the reversal of which may involve the combined action of chromatin regulators, pluripotency transcription factors and chromatin topology. Taken together, our study provides the chromosome-wide dynamics of gene reactivation from the randomly inactivated X-chromosome and a framework for understanding how transcription factors induce dynamic reversal of stable epigenetic memory by overcoming repressive chromatin barriers.

2019-02-08 | GSE126229 | GEO

PRC2 represses transcriptionally competent genes on the inactive X-chromosome

Project description:Polycomb repressive complex 2 (PRC2) catalyzes histone H3K27me3, which characterizes many silenced genes including those on the inactive X-chromosome. Here we interrogate the role of core PRC2 protein EED in X-linked gene silencing by assessing allele-specific X-linked gene expression in WT and Eed-/- hybrid mouse trophoblast stem cells (TSCs) harboring a 129/S1-derived maternal X-chromosome and a JF1/Ms-derived paternal X-chromosome. This study generates mRNA-seq data for WT and Eed-/- TSCs, which undergo imprinted inactivation of the paternal X-chromosome. RNA-seq data was mapped allele-specifically to in silico strain-specific maternal and paternal reference genomes, generated based on known single nucleotide polymorphisms. We find that EED loss abrogates H3K27me3 and expression of Xist lncRNA, which is required for X-inactivation, however, despite the absence of H3K27me3 and Xist, only a subset of PRC2 target genes are derepressed in Eed-/- TSCs.

2017-04-07 | GSE84681 | GEO

Effects of Firre knockdown on mouse gene expression

Project description:In mammals, genes located on the X chromosome are present in one copy in XY males and two in XX females. To balance the dosage of X-linked gene expression between the sexes one of the two X chromosomes in females is silenced by X inactivation initiated by up-regulation of the lncRNA (long non-coding RNA) Xist and recruitment of specific chromatin modifiers for silencing. The inactivated X chromosome becomes heterochromatic and visits a specific nuclear compartment adjacent to the nucleolus. We report a novel role for the X-linked lncRNA Firre in anchoring the inactive mouse X chromosome and preserving one of its main epigenetic features, trimethylation of histone H3 at lysine 27 (H3K27me3). Similar to Dxz4, Firre is expressed from a macrosatellite repeat locus associated with a cluster of CTCF and cohesin binding specifically on the inactive X. CTCF binding initially present in both male and female mouse embryonic stem cells was found to be lost from the active X during development. The Firre and Dxz4 loci on the inactive X were preferentially located adjacent to the nucleolus. Knockdown of Firre RNA disrupted perinucleolar targeting and H3K27me3 levels in mouse fibroblasts, demonstrating an important role for this lncRNA in maintenance of one of the main epigenetic features of the X chromosome. There was no X-linked gene reactivation after Firre knockdown; however, a compensatory increase in the expression of chromatin modifier genes implicated in X silencing was observed. In female ES cells Firre RNA knockdown did not disrupt Xist expression/coating nor silencing of G6pdx during differentiation, suggesting that Firre does not play a role in the onset of X inactivation. We conclude that the X-linked lncRNA Firre helps position the inactive X chromosome near the nucleolus and preserve one of its main epigenetic features. Examination of allelic expression in Patski cells upon Firre knockdown.

2015-03-05 | E-GEOD-66172 | biostudies-arrayexpress

Female-specific CTCF binding on the inactive X chromosome in mouse

2015-02-26 | E-GEOD-66262 | biostudies-arrayexpress

Identification of SNPs using genomic DNA and allele specific expression using nascent RNA on snp6 array

Project description:Disappearance of the Barr body has long been considered a hallmark of cancer, although whether this corresponds to epigenetic instability and transcriptional reactivation, or to genetic loss, has remained unclear. Here we show that in breast cancer cell lines as well as primary breast tumors, the inactive X chromosome frequently displays a highly abnormal 3D nuclear organization, with global perturbations in its characteristic heterochromatic state, including apparent gain of euchromatic marks and lessening of repressive marks such as H3K27me3 and promoter DNA methylation. Genome-wide profiling of chromatin and transcription reveal modified epigenomic landscapes in cancer cells accompanied by a significant degree of X-linked gene reactivation, affecting genes previously implicated in cancer, including the histone deacetylase, HDAC8 and transducin (Beta)-Like 1X-Linked, TBL1X. We provide proof of principle that epigenetic deregulation can indeed perturb the dosage of some X-linked factors and demonstrate that many of these genes are reactivated in primary breast tumors. Our study establishes that the inactive X is subject to epigenetic erosion in a cancer context and sets the stage for the use of chromatin marks and X- chromosome genes as potential biomarkers to assess epigenetic changes in cancer. Examination of allele specific expression of genes using nascent RNA on snp6 array by comparing it with snp6 results from genomic DNA.

2015-01-22 | E-GEOD-62965 | biostudies-arrayexpress

Analysis of allele specific expression and its chromatin state to identify genes that are escaping X chromosome inactivation

Project description:Disappearance of the Barr body has long been considered a hallmark of cancer, although whether this corresponds to epigenetic instability and transcriptional reactivation, or to genetic loss, has remained unclear. Here we show that in breast cancer cell lines as well as primary breast tumors, the inactive X chromosome frequently displays a highly abnormal 3D nuclear organization, with global perturbations in its characteristic heterochromatic state, including apparent gain of euchromatic marks and lessening of repressive marks such as H3K27me3 and promoter DNA methylation. Genome-wide profiling of chromatin and transcription reveal modified epigenomic landscapes in cancer cells accompanied by a significant degree of X-linked gene reactivation, affecting genes previously implicated in cancer, including the histone deacetylase, HDAC8 and transducin (Beta)-Like 1X-Linked, TBL1X. We provide proof of principle that epigenetic deregulation can indeed perturb the dosage of some X-linked factors and demonstrate that many of these genes are reactivated in primary breast tumors. Our study establishes that the inactive X is subject to epigenetic erosion in a cancer context and sets the stage for the use of chromatin marks and X- chromosome genes as potential biomarkers to assess epigenetic changes in cancer. Examination of allele specific expression of genes in chrX using histone marks, transcriptome, exome and SNP data on two normal cell-line and three cancer cell-line.

2015-01-22 | E-GEOD-62966 | biostudies-arrayexpress

XIST modulates mammary stem cell homeostasis and tumor fate [WT and KO RNA-seq]

Project description:Disruption of XIST expression in mammary epithelial cells leads to chromatin changes on the inactive X chromosome, transcriptional reactivation of X-linked genes, and defective luminal differentiation.

2022-01-06 | GSE192931 | GEO