Arabidopsis Generation Project
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB70284 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find Megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X-chromosome in induced pluripotent stem cell (iPSC)-derived neural progenitors, B-cells, and fibroblasts with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication stress-induced double strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the full-mutation CGG to premutation-length reverses H3K9me3 domains on the X-chromosome and multiple autosomes, refolds TADs, and restores expression. H3K9me3 domains also arise in a subset of normal-length iPSCs with increased STR instability burden. Our results reveal Mb-scale heterochromatinization and trans interactions among chromosomes susceptible to repeat genetic instability.
2023-12-21 | GSE218679 | GEO
Project description:Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find Megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X-chromosome in induced pluripotent stem cell (iPSC)-derived neural progenitors, B-cells, and fibroblasts with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication stress-induced double strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the full-mutation CGG to premutation-length reverses H3K9me3 domains on the X-chromosome and multiple autosomes, refolds TADs, and restores expression. H3K9me3 domains also arise in a subset of normal-length iPSCs with increased STR instability burden. Our results reveal Mb-scale heterochromatinization and trans interactions among chromosomes susceptible to repeat genetic instability.
2023-12-21 | GSE218678 | GEO
Project description:Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find Megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X-chromosome in induced pluripotent stem cell (iPSC)-derived neural progenitors, B-cells, and fibroblasts with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication stress-induced double strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the full-mutation CGG to premutation-length reverses H3K9me3 domains on the X-chromosome and multiple autosomes, refolds TADs, and restores expression. H3K9me3 domains also arise in a subset of normal-length iPSCs with increased STR instability burden. Our results reveal Mb-scale heterochromatinization and trans interactions among chromosomes susceptible to repeat genetic instability.
2023-12-21 | GSE218677 | GEO
Project description:Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find Megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X-chromosome in induced pluripotent stem cell (iPSC)-derived neural progenitors, B-cells, and fibroblasts with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication stress-induced double strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the full-mutation CGG to premutation-length reverses H3K9me3 domains on the X-chromosome and multiple autosomes, refolds TADs, and restores expression. H3K9me3 domains also arise in a subset of normal-length iPSCs with increased STR instability burden. Our results reveal Mb-scale heterochromatinization and trans interactions among chromosomes susceptible to repeat genetic instability.
2023-12-21 | GSE218676 | GEO
Project description:Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find Megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X-chromosome in induced pluripotent stem cell (iPSC)-derived neural progenitors, B-cells, and fibroblasts with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication stress-induced double strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the full-mutation CGG to premutation-length reverses H3K9me3 domains on the X-chromosome and multiple autosomes, refolds TADs, and restores expression. H3K9me3 domains also arise in a subset of normal-length iPSCs with increased STR instability burden. Our results reveal Mb-scale heterochromatinization and trans interactions among chromosomes susceptible to repeat genetic instability.
2023-12-21 | GSE218675 | GEO
Project description:Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find Megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X-chromosome in induced pluripotent stem cell (iPSC)-derived neural progenitors, B-cells, and fibroblasts with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication stress-induced double strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the full-mutation CGG to premutation-length reverses H3K9me3 domains on the X-chromosome and multiple autosomes, refolds TADs, and restores expression. H3K9me3 domains also arise in a subset of normal-length iPSCs with increased STR instability burden. Our results reveal Mb-scale heterochromatinization and trans interactions among chromosomes susceptible to repeat genetic instability.
2023-12-21 | GSE218674 | GEO
Project description:In plants, RNA polymerase II (Pol II) transcription of inverted DNA repeats produces hairpin RNAs that are processed by several DICER-LIKE enzymes into siRNAs that are 21-24-nt in length. When targeted to transcriptional regulatory regions, the 24-nt size class can induce RNA-directed DNA methylation (RdDM) and transcriptional gene silencing (TGS). In a forward genetic screen to identify mutants defective in RdDM of a target enhancer leading to TGS of a downstream GFP reporter gene in Arabidopsis thaliana, we recovered a structurally mutated silencer locus, named SM-NM-^T35S, in which the 35S promoter driving transcription of an inverted repeat of target enhancer sequences had been specifically deleted. Although Pol II-dependent, hairpin-derived 21-24-nt siRNAs were no longer generated at the newly created SM-NM-^T35S locus, the GFP reporter gene was nevertheless still partially silenced. Silencing was associated with methylation in a short tandem repeat in the upstream target enhancer and with low levels of 24-nt tandem repeat siRNAs. Introducing an nrpd1 mutation into the SM-NM-^T35S line fully released GFP silencing and eliminated both the tandem repeat methylation and associated 24-nt siRNAs, demonstrating their dependence on Pol IV. Deletion of the 35S promoter thus revealed a Pol IV-dependent pathway of 24-nt siRNA biogenesis that was previously inhibited or masked by the Pol II-dependent pathway in wild-type plants. Both Pol II- and Pol IV-dependent siRNAs accrued predominantly from cytosine (C)-containing segments of the tandem repeat monomer, suggesting that the local base composition influenced siRNA accumulation. Preferential accumulation of siRNAs at C-containing sequences was also observed at an endogenous tandem repeat comprising discrete C-rich and AT-rich sections. Our studies illuminate the potential complexity of siRNA generation at repeat-containing loci and show that Pol IV can act in siRNA biogenesis in the absence of a conventional Pol II promoter. Examination of whole-genome DNA methylation status in transgenic T+S Arabidopsis plant
2013-05-30 | E-GEOD-47453 | biostudies-arrayexpress
Project description:A targeted gene panel that covers coding, noncoding, and short tandem repeat regions improves the diagnosis of patients with neurodegenerative diseases
| EGAD00001005114 | EGA