Defects in dosage compensation impact global gene regulation in the mouse trophoblast
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE93031 | GEO | 2017/07/17
SECONDARY ACCESSION(S): PRJNA359489
REPOSITORIES: GEO
Similar Datasets
Project description:X chromosome inactivation (XCI) compensates for differences in X-chromosome number between male and female mammals. XCI is orchestrated by Xist RNA, whose expression in early development leads to transcriptional silencing of one X-chromosome in the female. Knockout studies have established a requirement for Xist, with inviability of female embryos that inherit an Xist deletion from the father. Here, we report that female mice lacking Xist RNA can, surprisingly, develop and survive to term. Xist-null females are born at lower frequency and are smaller at birth, but organogenesis is mostly normal. Transcriptomic analysis indicates significant overexpression of hundreds of X-linked genes across multiple tissues. Therefore, Xist-null mice can develop to term in spite of a deficiency of dosage compensation. However, the degree of X-autosomal dosage imbalance was less than anticipated (1.14- to 1.36-fold). Thus, partial dosage compensation can be achieved without Xist, supporting the idea of inherent genome balance. Nevertheless, to date, none of the mutant mice has survived beyond weaning stage. Sudden death is associated with failure of postnatal organ maturation. Our data suggest Xist-independent mechanisms of dosage compensation and demonstrate that small deviations from X-autosomal balance can have profound effects on overall fitness. RNA-sequencing of tail-tip fibroblasts (TTFs), spleen, liver and heart tissue from Xist-null and control female mice. Sequencing performed with 50nt read length on Illumina HiSeq2000 or 2500. Data consists of 3 biological replicates for TTFs (6 datasets) and 2 biological replicates for tissues (12 datasets).
2016-08-19 | E-GEOD-84665 | biostudies-arrayexpress
Project description:X chromosome inactivation (XCI) compensates for differences in X-chromosome number between male and female mammals. XCI is orchestrated by Xist RNA, whose expression in early development leads to transcriptional silencing of one X-chromosome in the female. Knockout studies have established a requirement for Xist, with inviability of female embryos that inherit an Xist deletion from the father. Here, we report that female mice lacking Xist RNA can, surprisingly, develop and survive to term. Xist-null females are born at lower frequency and are smaller at birth, but organogenesis is mostly normal. Transcriptomic analysis indicates significant overexpression of hundreds of X-linked genes across multiple tissues. Therefore, Xist-null mice can develop to term in spite of a deficiency of dosage compensation. However, the degree of X-autosomal dosage imbalance was less than anticipated (1.14- to 1.36-fold). Thus, partial dosage compensation can be achieved without Xist, supporting the idea of inherent genome balance. Nevertheless, to date, none of the mutant mice has survived beyond weaning stage. Sudden death is associated with failure of postnatal organ maturation. Our data suggest Xist-independent mechanisms of dosage compensation and demonstrate that small deviations from X-autosomal balance can have profound effects on overall fitness.
2016-08-19 | GSE84665 | GEO
Project description:For a brief but critical period post-fertilization, the mammalian embryo is entirely dependent on maternal products inherited from the oocyte. Previous research showed that oocyte-specific loss of Med12, an X-linked gene and Mediator complex subunit, leads to female sterility despite normal folliculogenesis and ovulation. Here, we show that loss of maternal Med12 has minimal effect on the oocyte transcriptome and does not manifest in embryonic lethality until post-implantation. Implants derived from Med12-null oocytes demonstrate abnormal placentation at E9.5, with an overabundance of trophoblast giant cells (TGC). This phenotype associates with downregulation of trophoblast pluripotency markers (e.g. Cdx2) and activation of drivers of TGC identity (e.g. Stra13) in the E7.5 extraembryonic ectoderm, revealing a previously undescribed role for Med12 in trophoblast pluripotency maintenance. Notably, we find consistently low Med12 expression in embryos derived from Med12-null oocytes, potentially due to programmed paternal X chromosome inactivation (XCI). To isolate the consequences of maternal Med12 depletion, we introduced an autosomal Med12 transgene and show that embryonic expression of the transgene rescues development of Med12-null oocytes. We conclude that oocyte-specific deletion of Med12 produces a maternal-zygotic double knock-out in extraembryonic tissues due to paternal XCI, leading to loss of pluripotency in the trophoblast, placental malformation, and embryonic death.
2025-05-13 | GSE281910 | GEO
Project description:X chromosome inactivation (XCI) triggers drastic reorganization of chromatin architecture, which in turn facilitates XCI. However, how the 3D organization is de novo established during XCI in vivo remains poorly understood. Mouse embryos present an ideal model, as they undergo imprinted XCI, X chromosome reactivation (XCR) and subsequent random XCI. Using low-input Hi-C, we revealed a unique chromatin structure of the inactive X chromosome (Xi) during both imprinted and random XCI in early mouse embryos. A bipartite structure featured by two megadomains separated by Xist (X-megadomains), emerges in extraembryonic lineages, derived extraembryonic endoderm (XEN) cells, and also transiently in embryonic lineages. X-megadomains then diminish in adult tissues, where previously reported Dxz4-delineated megadomains (D-megadomains) appear in a strain-specific manner. Mechanistically, X-megadomains coincide with developmentally controlled activities of regulatory regions near Xist (XRRs), and loss of XRR disrupts X-megadomains. CUT&RUN revealed strong enrichment of CTCF and cohesin near Xist, despite global depletion, on Xi in embryos and XEN cells. X-megadomains are also impaired when Xist is silenced, accompanied by global cohesin restoration, or when residual cohesin is degraded, suggesting that X-megadomain formation is promoted by both global cohesin depletion and local cohesin loading. Importantly, the loss of cohesin leads to ectopic activation of regulatory elements and genes near Xist. Hence, these data reveal programming of chromatin architecture during de novo establishment of mammalian XCI in vivo, and suggest that cohesin mediates self-insulation of gene activity of essential escapees amid global silencing.
2024-09-10 | GSE206010 | GEO
Project description:X chromosome inactivation (XCI) triggers drastic reorganization of chromatin architecture, which in turn facilitates XCI. However, how the 3D organization is de novo established during XCI in vivo remains poorly understood. Mouse embryos present an ideal model, as they undergo imprinted XCI, X chromosome reactivation (XCR) and subsequent random XCI. Using low-input Hi-C, we revealed a unique chromatin structure of the inactive X chromosome (Xi) during both imprinted and random XCI in early mouse embryos. A bipartite structure featured by two megadomains separated by Xist (X-megadomains), emerges in extraembryonic lineages, derived extraembryonic endoderm (XEN) cells, and also transiently in embryonic lineages. X-megadomains then diminish in adult tissues, where previously reported Dxz4-delineated megadomains (D-megadomains) appear in a strain-specific manner. Mechanistically, X-megadomains coincide with developmentally controlled activities of regulatory regions near Xist (XRRs), and loss of XRR disrupts X-megadomains. CUT&RUN revealed strong enrichment of CTCF and cohesin near Xist, despite global depletion, on Xi in embryos and XEN cells. X-megadomains are also impaired when Xist is silenced, accompanied by global cohesin restoration, or when residual cohesin is degraded, suggesting that X-megadomain formation is promoted by both global cohesin depletion and local cohesin loading. Importantly, the loss of cohesin leads to ectopic activation of regulatory elements and genes near Xist. Hence, these data reveal programming of chromatin architecture during de novo establishment of mammalian XCI in vivo, and suggest that cohesin mediates self-insulation of gene activity of essential escapees amid global silencing.
2024-09-10 | GSE206178 | GEO
Project description:Down syndrome is a common disorder with enormous medical and social costs, caused by trisomy for Chr21. We tested the concept that gene imbalance across an extra chromosome can be de facto corrected in DS patient stem cells by manipulating a single gene, XIST. Using zinc finger nucleases, we targeted a large, inducible XIST transgene into the Chr21 DYRK1A locus, in DS pluripotent stem cells. XIST RNA coats Chr21 and triggers stable heterochromatin modifications, chromosome-wide transcriptional silencing and DNA methylation to form a “Chr21 Barr Body.” This provides a model to study human chromosome inactivation and creates a system to investigate genomic expression changes and cellular pathologies of trisomy 21, free from genetic and epigenetic noise. In this study, we used microarrays to understand the genome-wide impacts of inducible XIST expression on Chr21 in trisomy 21 human iPS cell lines, and to evaluate the extent of Chr21 silencing trisomic samples versus a disomic male iPS cell line.
2013-07-12 | GSE47014 | GEO
Project description:Down syndrome is a common disorder with enormous medical and social costs, caused by trisomy for Chr21. We tested the concept that gene imbalance across an extra chromosome can be de facto corrected in DS patient stem cells by manipulating a single gene, XIST. Using zinc finger nucleases, we targeted a large, inducible XIST transgene into the Chr21 DYRK1A locus, in DS pluripotent stem cells. XIST RNA coats Chr21 and triggers stable heterochromatin modifications, chromosome-wide transcriptional silencing and DNA methylation to form a M-bM-^@M-^\Chr21 Barr Body.M-bM-^@M-^] This provides a model to study human chromosome inactivation and creates a system to investigate genomic expression changes and cellular pathologies of trisomy 21, free from genetic and epigenetic noise. In this study, we used microarrays to understand the genome-wide impacts of inducible XIST expression on Chr21 in trisomy 21 human iPS cell lines, and to evaluate the extent of Chr21 silencing trisomic samples versus a disomic male iPS cell line. Three independently targeted subclones plus the parental Chr21 trisomic (non-targeted) iPS cell line were grown M-BM-1 doxycycline (2 M-BM-5g/ml) for 22 d. Normal male iPS line was also cultured for 22 d and total RNA was extracted with a High Pure RNA extraction kit (Roche) in triplicate for each, processed with a Gene Chip 3M-bM-^@M-^Y IVT Express Kit (Affymetrix), and hybridized to Affymetrix human gene expression PrimeView arrays. Array normalization was performed with Affymetrix Expression Console Software with Robust Multichip Analysis (RMA). Probesets with the top 60% of signal values were considered present and M-bM-^@M-^\expressedM-bM-^@M-^] and were used for all further analysis. In total 9 RNA samples were prepared in triplicate for a total of 27 arrays.
2013-07-12 | E-GEOD-47014 | biostudies-arrayexpress
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: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:X chromosome inactivation (XCI) triggers a drastic reprogramming of gene activities and chromosome architecture. However, how the 3D organization of the inactive X chromosome (Xi) is de novo established in vivo in mammals remains poorly understood. By comprehensive stage- and lineage- specific Hi-C mapping, we identified a unique Xist-separated megadomain structure (X-megadomains) on the Xi in mouse early embryos. X-megadomains emerge in extraembryonic lineages during imprinted XCI, in derived extraembryonic endoderm (XEN) cells, and transiently in the embryonic lineages during random XCI, before Dxz4-delineated megadomains (D-megadomains) occur at later stages in a strain-specific manner. Mechanistically, the emergence of X-megadomain boundary coincides with developmentally regulated enhancer activities and cohesin binding in a regulatory region near Xist (XRR). We pinpointed a subregion XRRa that is critical for the X-megadomain boundary. X-megadomains are impaired when XRRa is removed or cohesin is degraded in XEN cells. Importantly, this is accompanied by ectopic activation of regulatory elements and genes near Xist, suggesting that cohesin loading at regulatory elements promotes X-megadomains and confines local gene activities. Finally, the knockout of XRRa in mouse preimplantation embryos severely impairs the activation of Xist and the initiation of XCI. Hence, our data not only reveal stepwise chromosome folding during de novo XCI in vivo, but also support a model that regulatory element-dependent gene activation and cohesin loading simultaneously promote essential transcription activities and subsequent self-insulation amid global silencing during the early stage of XCI.
2024-09-10 | GSE206158 | GEO