X-linked deletion of Crossfirre, Firre, and Dxz4 in vivo uncovers diverse phenotypes and combinatorial effects on autosomes
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE219160 | GEO | 2024/10/28
REPOSITORIES: GEO
Similar Datasets
Project description:Recent evidence has determined that the conserved X chromosome “mega-structures” controlled by the Firre and Dxz4 alleles are not required for X chromosome inactivation (XCI) in cell lines. Here we determined the in vivo contribution of these alleles individually and in combination and found that mutant mice are viable, fertile and show no defect in random or imprinted XCI. However, the lack of these elements results in many dysregulated genes on autosomes in an organ-specific manner, suggesting that these X-linked loci are involved in autosomal gene regulation rather than XCI biology.
2019-11-15 | GSE127554 | GEO
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
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 protein-binding or histone modification profiles in Patski cells.
2015-02-26 | E-GEOD-66262 | biostudies-arrayexpress
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.
2015-02-26 | GSE66262 | GEO
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.
2015-03-05 | GSE66172 | GEO
Project description:The mammalian inactive X-chromosome (Xi) is structurally distinct from all other chromosomes and serves as a model for higher order chromosome organization. The Xi lacks strong topologically associated domains and is instead organized into megadomains and superloops mediated in part by the noncoding loci, Dxz4 and Firre. Their functional significance is presently unclear, though one study suggests that they permit Xi genes to escape silencing. Here, we find that megadomains do not form before silencing spreads along the Xi. Deletional analysis shows that Dxz4, but not Firre, is required for megadomains. Surprisingly, however, deleting neither Dxz4 nor Firre impacts Xi silencing or gene escape. Nor does it affect Xi nuclear localization, stability, or H3K27 methylation. Furthermore, ectopic integration of Dxz4 and Xist is not sufficient to form megadomains on autosomes, thereby uncoupling megadomain formation from chromosomal silencing. We conclude that Dxz4 and megadomains are dispensable for Xi silencing and escape.
2018-10-31 | GSE116649 | GEO
Project description:During interphase, the inactive X chromosome (Xi) adopts an unusual 3D configuration known as the Barr body and is largely transcriptionally silent. Despite the importance of X inactivation, little is known about the 3D configuration of Xi and its relationship to gene silencing. We recently showed that in humans, Xi exhibits two distinctive structural features. First, Xi is partitioned into two huge intervals, called superdomains, such that pairs of loci in each superdomain show an enhanced contact frequency with one another. The boundary between the two superdomains lies near DXZ4, a macrosatellite repeat spanning ~300kb, whose Xi allele extensively binds the protein CTCF. Second, Xi exhibits extremely large loops, up to 77Mb long, called superloops. DXZ4 lies at the anchor of several superloops. Here, we use 3D mapping to study the structure of Xi, focusing on the role of DXZ4. We show that superloops and superdomains are conserved across mammals. We develop a novel variant of our in situ Hi-C protocol, dubbed COLA (COncatemer Ligation Assay) to probe the higher order structures formed by the superloops. In COLA, in situ proximity ligation of multiple extremely short fragments produced by the enzyme CviJI is used to efficiently map simultaneous proximity among three or more loci. Using data from Hi-C and COLA, we demonstrate that DXZ4 and other superloop anchors tend to co-locate simultaneously within the same cells, a result that is confirmed by 3D-FISH. Finally, we examine the effects of deleting DXZ4 from Xi in human cells. Using in situ Hi-C, microscopy, and RNA-FISH, we show that superdomains and superloops disappear; that Xi frequently dissociates into multiple separate structures; and that transcriptional silencing on Xi is compromised. Deletion of DXZ4 from the active X chromosome (Xa) has no such effect. Thus, DXZ4 is essential for proper folding and silencing of Xi. Hi-C protocol was used on wildtype and DXZ4-deleted cells to examine the structure of Xi. A novel variant of our in situ Hi-C protocol, dubbed COLA (COncatemer Ligation Assay), was developed to probe the higher order structures formed by the superloops. This series also includes RNA-seq data on Retinal Pigmented Epithelial Cells (hTERT-RPE1). At the time of submission, processed data were available only for the RNA-seq samples. Submitter states that processed data files for HiC samples will be added to this series in the future.
2016-07-19 | E-GEOD-71831 | biostudies-arrayexpress
Project description:In vivo Firre and Dxz4 deletion elucidates roles for autosomal gene regulation
| PRJNA525066 | ENA
Project description:During interphase, the inactive X chromosome (Xi) adopts an unusual 3D configuration known as the Barr body and is largely transcriptionally silent. Despite the importance of X inactivation, little is known about the 3D configuration of Xi and its relationship to gene silencing. We recently showed that in humans, Xi exhibits two distinctive structural features. First, Xi is partitioned into two huge intervals, called superdomains, such that pairs of loci in each superdomain show an enhanced contact frequency with one another. The boundary between the two superdomains lies near DXZ4, a macrosatellite repeat spanning ~300kb, whose Xi allele extensively binds the protein CTCF. Second, Xi exhibits extremely large loops, up to 77Mb long, called superloops. DXZ4 lies at the anchor of several superloops. Here, we use 3D mapping to study the structure of Xi, focusing on the role of DXZ4. We show that superloops and superdomains are conserved across mammals. We develop a novel variant of our in situ Hi-C protocol, dubbed COLA (COncatemer Ligation Assay) to probe the higher order structures formed by the superloops. In COLA, in situ proximity ligation of multiple extremely short fragments produced by the enzyme CviJI is used to efficiently map simultaneous proximity among three or more loci. Using data from Hi-C and COLA, we demonstrate that DXZ4 and other superloop anchors tend to co-locate simultaneously within the same cells, a result that is confirmed by 3D-FISH. Finally, we examine the effects of deleting DXZ4 from Xi in human cells. Using in situ Hi-C, microscopy, and RNA-FISH, we show that superdomains and superloops disappear; that Xi frequently dissociates into multiple separate structures; and that transcriptional silencing on Xi is compromised. Deletion of DXZ4 from the active X chromosome (Xa) has no such effect. Thus, DXZ4 is essential for proper folding and silencing of Xi.
2016-07-19 | GSE71831 | GEO
Project description:X-linked deletion of Crossfirre, Firre, and Dxz4 in vivo uncovers diverse phenotypes and combinatorial effects on autosomes
| PRJNA907291 | ENA