Genomic imprinting of Xist by maternal H3K27me3
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE103714 | GEO | 2017/11/09
SECONDARY ACCESSION(S): PRJNA406729
REPOSITORIES: GEO
Similar Datasets
Project description:Genomic imprinting is essential for mammalian development. Recent studies have revealed that maternal histone H3 lysine 27 tri-methylation (H3K27me3) can mediate DNA methylation-independent genomic imprinting. However, the regulatory mechanisms and functions of this new imprinting mechanism are largely unknown. Here we demonstrate that maternal Eed, an essential component of the Polycomb group complex 2 (PRC2), is required for establishing H3K27me3 imprinting. We found that all H3K27me3 imprinted genes, including Xist, lose their imprinted expression in Eed maternal KO (matKO) embryos, resulting in male-biased lethality. Surprisingly, although maternal X chromosome inactivation (XmCI) occurs in Eed matKO embryos at preimplantation due to loss of Xist imprinting, it is resolved at peri-implantation. Ultimately, both X chromosomes are reactivated in the embryonic cell lineage prior to random XCI, and only a single X chromosome undergoes random XCI in the extra-embryonic cell lineage. Thus, our study not only demonstrates an essential role of Eed in H3K27me3 imprinting establishment but also reveals a unique XCI dynamics in the absence of Xist imprinting.
2018-11-26 | GSE116713 | GEO
Project description:Genomic imprinting regulates parental origin-dependent mono-allelic gene expression. It is mediated by either germline differential methylation of DNA (canonical imprinting) or oocyte-derived H3K27me3 (non-canonical imprinting) in mice. Depletion of Eed, an essential component of Polycomb repressive complex 2, results in genome-wide loss of H3K27me3 in oocytes, which causes loss of non-canonical imprinting (LOI) in embryos. Although Eed maternal KO (matKO) embryos show partial lethality after implantation, it is unknown whether LOI itself contributes to the developmental phenotypes of these embryos, which makes it unclear whether non-canonical imprinting is developmentally relevant. Here, by combinatorial matKO of Xist, a non-canonical imprinted gene whose LOI causes aberrant transient maternal X chromosome inactivation (XCI) at preimplantation, we show that prevention of the transient maternal XCI greatly restores the development of Eed matKO embryos. Moreover, we find that the placentae of Eed matKO embryos are remarkably enlarged in a manner independent of Xist LOI. Heterozygous deletion screening of individual autosomal non-canonical imprinted genes suggests that LOI of the Sfmbt2 miRNA cluster-chromosome 2 miRNA cluster (C2MC), solute carrier family 38 member 4 (Slc38a4), and Gm32885 contributes to the placental enlargement. Taken together, our study provides evidence that Xist imprinting sustains embryonic development and autosomal non-canonical imprinting restrains placental overgrowth.
2022-06-30 | GSE199115 | GEO
Project description:Xist represents a paradigm for long non-coding RNA function in epigenetic regulation, although how it mediates X-chromosome inactivation (XCI) remains largely unexplained. Multiple Xist-RNA binding proteins have recently been identified, including SPEN/SHARP, whose knockdown has been associated with deficient XCI at multiple loci. Here we demonstrate that SPEN is a key orchestrator of XCI in vivo and unravel its mechanism of action. We show that SPEN is essential for initiating gene silencing on the X chromosome in preimplantation mouse embryos and embryonic stem cells. On the other hand, SPEN is dispensable for maintenance of XCI in neural progenitor cells, although it significantly dampens expression of genes that escape from XCI. During initiation of XCI, we show by live-cell imaging and CUT&RUN approaches that SPEN is immediately recruited to the X chromosome upon Xist up-regulation, where it is targeted to enhancers and promoters of actively transcribed genes. SPEN rapidly disengages from chromatin once silencing is accomplished, implying a need for active transcription to tether it to chromatin. We define SPEN’s SPOC (SPEN paralog and ortholog C-terminal) domain as a major effector of SPEN’s gene silencing function, and show that artificial tethering of SPOC to Xist RNA is sufficient to mediate X-linked gene silencing. We identify SPOC’s protein partners which include NCOR/SMRT, the m6A RNA methylation machinery, the NuRD complex, RNA polymerase II and factors involved in regulation of transcription initiation and elongation. We propose that SPEN acts as a molecular integrator for initiation of XCI, bridging Xist RNA with the transcription machinery as well as nucleosome remodelers and histone deacetylases, at active enhancers and promoters.
2021-04-19 | PXD015699 | Pride
Project description:Purpose: Compare the transcriptome of homogeneous XIST+ and XIST- hES cell populations. Methods: We isolated homogeneous XIST+ and XIST- cell populations. The XIST+ cells correspond to cells with a XIST cloud and one ATRX pinpoint. The XIST- cells correspond to cells with no XIST cloud and one ATRX pinpoint. Results: We took advantage of the clonal pattern of X-chromosome inactivation in H9 cells and analyzed the data in an allelic manner. By comparing the RNA-Seq data with known H9 SNPs, we identified genomic positions which were relaxed from XCI in XIST- cells compared to XIST+ cells. Conclusions: Genic as well as unannotated transcripts are massively relaxed from XCI in H9 cells when XIST expression is lost, however, this reactivation is only partial and a large region around the centromere is protected from relaxation of silencing. Total RNA (rRNA depleted) profiles of XIST+ and XIST- human embryonic stem cells
2012-12-21 | E-GEOD-39757 | biostudies-arrayexpress
Project description:Faithful maintenance of genomic imprinting is essential for mammalian development. While germline DNA methylation-dependent (canonical) imprinting is relatively stable during development, the recently discovered oocyte-derived H3K27me3-mediated noncanonical imprinting is mostly transient in early embryos with only a few genes maintain imprinted expression in the extraembryonic lineage. How these few noncanonical imprinted genes maintain their extraembryonic-specific imprinting is unknown. Here we report that maintenance of extraembryonic-specific noncanonical imprinting requires maternal allele-specific de novo DNA methylation (secondary differentially methylation regions; DMRs) at implantation. The secondary DMRs are located at the gene promoters with paternal allele-specific H3K4me3 preformed during preimplantation development. Importantly, genetic ablation of Eed and DNA methyltransferases revealed that both maternal H3K27me3 and zygotic Dnmt3a/3b are required for establishing secondary DMRs and for maintaining noncanonical imprinting. Thus, our study not only reveals the mechanism underlying maintenance of noncanonical imprinting, but also sheds light on how histone modifications in oocytes and preimplantation embryos may shape the secondary DMRs in post-implantation embryos.
2019-12-26 | GSE130115 | GEO
Project description:In this project, we have studied the role of Chd8 in Xist regulation and XCI initiation by means of Chd8 Knock-Downs (KD) and Knock-Out (KO).
2021-09-10 | PXD024155 | Pride
Project description:The Xist long noncoding RNA (lncRNA) is essential for X-chromosome inactivation (XCI), the process by which mammals compensate for unequal numbers of sex chromosomes. During XCI, Xist coats the future inactive X (Xi) and recruits Polycomb Repressive Complex 2 (PRC2) to the X-inactivation center (Xic). Currently unclear is how Xist spreads silencing on a 150 Mb scale. Here we generate high-resolution maps of Xist binding across a developmental time course using CHART-seq. In female cells undergoing XCI de novo, Xist follows a two-step mechanism in which it initially targets gene-rich islands before spreading to intervening gene-poor domains. Xist is depleted from genes that escape XCI but frequently concentrates near escapee boundaries. Xist binding was linearly proportional to PRC2 density and H3 lysine 27 trimethylation (H3K27me3), suggesting co-migration of Xist and PRC2. Interestingly, when the Xi is acutely stripped of Xist in post-XCI cells, Xist recovers quickly within both gene-rich and -poor domains on a time scale of hours instead of days, suggesting a previously primed Xi chromatin state. We conclude that Xist spreading takes on distinct stage-specific forms: During initial establishment, Xist follows a two-step mechanism, but during maintenance, Xist spreads rapidly to both gene-rich and -poor regions. Capture hybridization analysis of RNA targets (CHART) and input samples of (differentiating) mouse embryonic stem (ES) cells and immortalized mouse embryonic fibroblasts (MEF) using paired-end 75 nt reads on Illumina HiSeq2500, with 2 replicates per sample (# of samples). RNA-seq of the same cell lines with 50 nt reads on Illumina HiSeq2000, with 2 replicates per sample (2 samples, 4 datasets total). CHIP-seq: Data from GSE36905 was aligned and processed as CHART-seq samples. Resulting coverage tracks (EZH2/K27me3) are linked directly to GSE48649 (bedGraphs linked below).
2013-11-04 | E-GEOD-48649 | biostudies-arrayexpress
Project description:During X chromosome inactivation (XCI), in female mammals, gene silencing is initiated by a long-noncoding RNA, called Xist. Xist RNA accumulation also allows for the deposition of specific chromatin marks. Among others, PRC2-dependent H3K27me3 and PrSet7-dependent H4K20me1 become enriched at the inactive X chromosome. However, the dynamics of this process in relation to Xist RNA accumulation remains unknown as is the molecular mechanism allowing for H4K20me1 enrichment. To follow XCI dynamics in living cells, we developed a genetically encoded, H3K27me3-specific intracellular antibody, or H3K27me3-mintbody. By combining it with live-imaging of H4K20me1, the X chromosome and Xist RNA we uncover striking similarities in the accumulation dynamics of H3K27me3 and H4K20me1. Further ChIP-seq analysis confirmed concurrent accumulation of H4K20me1 and H3K27me3 during XCI albeit with distinct genomic distributions. Xist B and C repeat mutant, which can silence the X but does not allow for H3K27me3 enrichment, also showed lack of H4K20me1 deposition. Thus, both H3K27me3 and H4K20me1 are deposited at the inactive X through a common molecular mechanism but are dispensable for the initiation of gene silencing.
2021-02-26 | GSE153146 | GEO
Project description:Cloning mammals by somatic cell nuclear transfer (SCNT) is highly inefficient. Most SCNT-generated embryos die after implantation because of unidentified, complex epigenetic errors in the process of postimplantation embryonic development. Here, we identified the most upstream level of dysfunction leading to impaired development of clones by using RNA interference (RNAi) against Xist, a gene responsible for X chromosome inactivation (XCI). A prior injection of Xist-specific short interfering (si)RNA into reconstructed oocytes efficiently corrected the SCNT-specific aberrant Xist expression at the morula stage, but failed to do so thereafter at the blastocyst stage. However, we found that shortly after implantation this aberrant XCI status in cloned embryos had been corrected autonomously in both embryonic and extraembryonic tissues, probably through a newly established XCI control for postimplantation embryos. Embryo transfer experiments revealed that the siRNA-treated embryos showed 10 times higher survival than controls as early as embryonic day 5.5 and this high survival persisted until term, resulting in a remarkable improvement in cloning efficiency (12% vs. 1% in controls). Importantly, unlike control clones, these Xist-siRNA clones at birth showed only a limited dysregulation of their gene expression, indicating that correction of Xist expression in preimplantation embryos had a long-term effect on their postnatal normality. Thus, contrary to the general assumption, our results suggest that the fate of cloned embryos is determined almost exclusively before implantation by their XCI status. Furthermore, our strategy provides a promising breakthrough for mammalian SCNT cloning because RNAi treatment of oocytes is readily applicable to most mammal species. Gene expression were measured in mouse in vitro fertilized and somatic cell cloned embryos. Four biological replicates were performed in each group of Xist- or Control-siRNA.
2011-11-17 | E-GEOD-33208 | biostudies-arrayexpress
Project description:X chromosome inactivation (XCI) is a dosage compensation phenomenon that occurs in females. Initiation of XCI depends on Xist RNA, which triggers silencing of one of the two X chromosomes, except for XCI escape genes that continue to be biallelically expressed. In the soma XCI is stably maintained with continuous Xist expression. How Xist impacts XCI maintenance remains an open question. Here we conditionally deleted Xist in hematopoietic system of mice and report differentiation and cell cycle defects in female hematopoietic stem and progenitor cells (HPSCs). By utilizing female HSPCs and mouse embryonic fibroblasts, we find that X-linked genes show variable tolerance to Xist loss. Specifically, XCI escape genes exhibit preferential transcriptional upregulation, which associates with low H3K27me3 occupancy, and high chromatin accessibility that accommodates preexisting binding of transcription factors such as Yin Yang 1 (YY1) at the basal state. We conclude that Xist is necessary for gene-specific silencing during XCI maintenance and impacts lineage-specific cell differentiation and proliferation during hematopoiesis.
2022-07-15 | GSE184772 | GEO