Impact of flanking chromosomal sequences on localization and silencing by the ncRNA XIST
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Carolyn Brown
PROVIDER: E-GEOD-68109 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:We performed RNA-seq and ChIP-seq on clones of human cell lines carrying an inducible XIST transgene on 1p, 8p, or 12q to study the effects of allelic silencing in cis
2015-09-02 | GSE68109 | GEO
Project description:Millions of cis-regulatory sequences have recently been found in the human genome, but the function of most cis-elements are not yet clear, in part due to the difficulty in determining their regulatory targets, which are often located millions of base pairs away and separated by one or more unrelated genes. To address this problem, the Hi-C method has been developed to identify long-range looping interactions in a genome-wide, unbiased fashion. However, current data analysis of Hi-C datasets cannot fully resolve regulatory interactions between enhancers and promoters due to the low resolution. Here, we generated a high-depth Hi-C dataset and applied a new analysis method that offers improved resolution permitting genome-wide identification of nearly one million chromatin interactions. We demonstrated the use of Hi-C to identify target promoters of enhancers regulated by NF-M-NM-:B signaling and signal-dependent dynamic chromatin interaction at these enhancers in human cells. Surprisingly, our results showed that most NF-M-NM-:B binding sites are looped to their regulatory targets prior to activation of the signaling pathway, and appear to undergo little change during signaling. This observation suggests that the chromatin organization landscape, once established in a cell type, is rather stable and may influence the selection and activation of target genes by a transcription factor. We performed Hi-C analysis using a human fibroblast cell line IMR90 before and after NF-M-NM-:B activation. In the meantime, we also performed ChIP-seq experiments to map the location of NF-M-NM-:B p65 subunit, RNA polymerase II, p300, and several histone modifications (including H3K4me1, H3K4me3, H3K27ac and H3K36me3) in IMR90 cells before and after transient TNF-M-NM-1 stimulation. Additionally, to monitor the dynamic transcription profiles, we also performed Global Run-On sequencing (GRO-seq).
2013-10-20 | E-GEOD-43070 | biostudies-arrayexpress
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:The spatial organization of the genome is intimately linked to its biological function, yet our understanding of higher order genomic structure is limited. Here we present high-resolution analyses of chromosomal organization in pluripotent and differentiated human and murine cell types determined using the Hi-C technique. We find that the mammalian genome is composed of over 1000 topological domains, which are stable among different cell types and highly conserved across species. These megabase-long genomic structures, defined by prominent local chromatin interactions and separated by narrow boundary regions, likely function to restrict regulatory interactions between cis-acting elements and limit the spreading of heterochromatin during cellular differentiation. Interestingly, the boundaries are enriched not only for binding sites of the insulator protein CTCF, but also for promoters of house keeping genes, supporting a role for both CTCF and housekeeping genes in the establishment or maintenance of the topological domains. Hi-C experiment were conducted in mESC, hESC and IMR90 cells
2012-04-10 | E-GEOD-35156 | biostudies-arrayexpress
Project description:In eutherian mammals, dosage compensation of X-linked genes is achieved by X chromosome inactivation. X inactivation is random in embryonic and adult tissues, but imprinted X inactivation (paternal X silencing) has been identified in the extraembryonic membranes of the mouse, rat, and cow. Few other species have been studied for this trait, and the data from studies of the human placenta have been discordant or inconclusive. Here, we quantify X inactivation using RNA sequencing of placental tissue from reciprocal hybrids of horse and donkey (mule and hinny). In placental tissue from the equid hybrids and the horse parent the allelic expression pattern was consistent with random X inactivation, and imprinted X inactivation can clearly be excluded. We characterized horse and donkey XIST gene, and demonstrated that XIST allelic expression in female hybrid placental and fetal tissues is negatively correlated with the other X-linked genes chromosome-wide, which is consistent with the XIST-mediated mechanism of X inactivation discovered previously in mice. As the most structurally and morphologically diverse organ in mammals, the placenta also appears to show diverse mechanisms for dosage compensation that may result in differences in conceptus development across species. Examine allelic expression from individual samples of invasive trophoblast tissue of the chorionic girdle from gestation day 33-34 conceptuses of 5 horses, 3 donkeys, 6 mules, and 1 hinny.
2012-05-29 | E-GEOD-36352 | biostudies-arrayexpress
Project description:As the most widely used mammalian model organism, mice play a critical role in biomedical research for mechanistic study of human development and diseases. Today, functional sequences in the mouse genome are still poorly annotated a decade after its initial sequencing. We report here a map of nearly 300,000 cis-regulatory sequences in the mouse genome, representing active promoters, enhancers and CTCF binding sites in a diverse set of 19 tissues and cell types. This map provides functional annotation to nearly 11% of the genome, and over 70% of conserved, non-coding sequences. We define tissue-specific enhancers and identify potential transcription factors regulating gene expression in each tissue or cell type. Finally, we demonstrate that cis-regulatory sequences are organized into domains of coordinately regulated enhancers and promoters. Our results provide a valuable resource for the annotation of functional elements in the mammalian genome, and study of regulatory mechanisms for tissue-specific gene expression. Cortex Hi-C experiment were conducted in biological replicates
2012-06-30 | E-GEOD-34587 | biostudies-arrayexpress
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.
2012-12-21 | GSE39757 | GEO
Project description:In vertebrates, the catalytic core of PRC1 comprises RING1A/B and one of six homologues of the Polycomb group RING finger (PCGF) protein. Unique characteristics of PCGF1-6 in turn define distinct subunit assemblies, broadly subdivided into canonical and non-canonical PRC1 complexes. This RNA-seq experiment aimed to test the hypothesis that Pcgf3/5 gene knockout abrogates Xist mediated gene repression. In this experiment, Pcgf3fl/flPcgf5-/- and Pcgf3-/-Pcgf5-/- mESCs bearing Xist transgene on chromosome 16 (clone C3F8) were cultured in differentiating conditions: plated on non-gelatinized TC dish in ES medium without LIF for 72 hours with (+dox) and without doxycycline. RNA was isolated from 4 biological replicates. In analysed cells chromosome 16 bears inducible Xist and the whole study investigates role of PCGF3 and PCGF5 in Xist-dependednt gene silencing, therefore both bam files containing alignments and counts per gene were uploaded to ArrayExpress only for chromosome 16. Genome-wide data can be provided upon request.
2018-04-04 | E-MTAB-5642 | biostudies-arrayexpress
Project description:Naïve human embryonic stem cells (hESCs) can be derived from primed hESCs or directly from blastocysts, but their X-chromosome state has remained unresolved. We found that the inactive X-chromosome (Xi) of primed hESCs was reactivated in naïve culture conditions. Similar to cells of the blastocyst, resulting naive cells exhibited two active X-chromosomes with XIST expression and chromosome-wide transcriptional dampening, and initiated XIST-mediated X-inactivation upon differentiation. Both establishment and exit from the naïve state (differentiation) happened via an XIST-negative XaXa intermediate. Together, these findings identify a cell culture system for functionally exploring the two X-chromosome dosage compensation processes in early human development: X-dampening and X-inactivation. Furthermore, the naïve state reset Xi abnormalities of primed hESCs, providing cells better suited for downstream applications. However, naïve hESCs displayed differences to the embryo because XIST expression was predominantly mono-allelic instead of bi-allelic, and X-inactivation was non-random, indicating the need for further culture improvement.
2016-10-21 | GSE87235 | GEO
Project description:Naïve human embryonic stem cells (hESCs) can be derived from primed hESCs or directly from blastocysts, but their X-chromosome state has remained unresolved. We found that the inactive X-chromosome (Xi) of primed hESCs was reactivated in naïve culture conditions. Similar to cells of the blastocyst, resulting naive cells exhibited two active X-chromosomes with XIST expression and chromosome-wide transcriptional dampening, and initiated XIST-mediated X-inactivation upon differentiation. Both establishment and exit from the naïve state (differentiation) happened via an XIST-negative XaXa intermediate. Together, these findings identify a cell culture system for functionally exploring the two X-chromosome dosage compensation processes in early human development: X-dampening and X-inactivation. Furthermore, the naïve state reset Xi abnormalities of primed hESCs, providing cells better suited for downstream applications. However, naïve hESCs displayed differences to the embryo because XIST expression was predominantly mono-allelic instead of bi-allelic, and X-inactivation was non-random, indicating the need for further culture improvement.
2016-10-21 | GSE87231 | GEO