Similar Datasets
Project description:Epigenetic regulation depends on complex interactions between different epigenetic factors, such as DNA methylation and chromatin accessibility. As the gene activation potential cannot be predicted by looking at chromatin accessibility or DNA modification alone, methods capable of relating multiple factors are highly desirable. Existing methods for combined chromatin accessibility and DNA modification analysis rely on bisulfite sequencing, which has a number of well known drawbacks. We developed a novel cost-efficient method for simultaneous profiling of DNA methylation and hydroxymethylation within open chromatin loci. Our approach is based on chemo-enzymatic covalent tagging of unmodified (uCG) and hydroxymethylated (5hmC) CG sites along with GC sites in native chromatin, which are then mapped by tag-selective sequencing. Validation of the technology on model DNA systems and mammalian cells demonstrated a great applicability of this method for epigenomic studies. We employed the technology for tracking chromatin dynamics combined with changes of two different cytosine states, unmodified and hydroxymethylated, during differentiation of embryonic stem cells (ESC) which revealed extensive chromatin dynamics and DNA modification changes across gene bodies of development-associated genes at early transition from ESC. Strong DNA demethylation in the ESC-to-neuron differentiation pathway proceeds independently from cell transcriptional programs and highlights the value of separate 5hmC and 5mC analysis in understanding cell fate decisions.
2023-12-01 | GSE231928 | GEO
Project description:We performed differentiation of mouse ESC (mESC) into a population of radial-glial neuronal progenitor cells (NPC) and later into terminally differentiated glutamatergic pyramidal neuron cells (NC).
2023-12-01 | GSE231446 | GEO
Project description:Unified analysis of DNA methylation, hydroxymethylation and chromatin accessibility through targeted DNA labeling
| PRJNA970248 | ENA
Project description:Unified analysis of DNA methylation, hydroxymethylation and chromatin accessibility through targeted DNA labeling [TOP-Seq]
| PRJNA970253 | ENA
Project description:Unified analysis of DNA methylation, hydroxymethylation and chromatin accessibility through targeted DNA labeling [RNA-seq]
| PRJNA966072 | ENA
Project description:We present long-read Tet-assisted pyridine borane sequencing (lrTAPS) for targeted base-resolution sequencing of DNA methylation and hydroxymethylation in regions up to 10 kb from nanogram-level input. Compatible with both Oxford Nanopore and PacBio Single-Molecule Real-Time (SMRT) sequencing, lrTAPS detects methylation with accuracy comparable to short-read Illumina sequencing but with long-range epigenetic phasing. We applied lrTAPS to sequence difficult-to-map regions in mouse embryonic stem cells and to identify distinct methylation events in the integrated hepatitis B virus genome.
| S-EPMC7053107 | biostudies-literature
Project description:DNA methylation is a major epigenetic modification found across species and has a profound impact on many biological processes. However, its influence on chromatin accessibility and higher-order genome organization remains unclear, particularly in plants. Here, we present genome-wide chromatin accessibility profiles of 18 Arabidopsis mutants that are deficient in CG, CHG, or CHH DNA methylation. We find that DNA methylation in all three sequence contexts impacts chromatin accessibility in heterochromatin. Many chromatin regions maintain inaccessibility when DNA methylation is lost in only one or two sequence contexts, and signatures of accessibility are particularly affected when DNA methylation is reduced in all contexts, suggesting an interplay between different types of DNA methylation. In addition, we found that increased chromatin accessibility was not always accompanied by increased transcription, suggesting that DNA methylation can directly impact chromatin structure by other mechanisms. We also observed that an increase in chromatin accessibility was accompanied by enhanced long-range chromatin interactions. Together, these results provide a valuable resource for chromatin architecture and DNA methylation analyses and uncover a pivotal role for methylation in the maintenance of heterochromatin inaccessibility.
| S-EPMC7865151 | biostudies-literature
Project description:Accessible chromatin and unmethylated DNA are associated with many genes and cis-regulatory elements. Attempts to understand natural variation for accessible chromatin regions (ACRs) and unmethylated regions (UMRs) often rely upon alignments to a single reference genome. This limits the ability to assess regions that are absent in the reference genome assembly and monitor how nearby structural variants influence variation in chromatin state. In this study, de novo genome assemblies for four maize inbreds (B73, Mo17, Oh43, and W22) are utilized to assess chromatin accessibility and DNA methylation patterns in a pan-genome context. A more complete set of UMRs and ACRs can be identified when chromatin data are aligned to the matched genome rather than a single reference genome. While there are UMRs and ACRs present within genomic regions that are not shared between genotypes, these features are 6- to 12-fold enriched within regions between genomes. Characterization of UMRs present within shared genomic regions reveals that most UMRs maintain the unmethylated state in other genotypes with only ∼5% being polymorphic between genotypes. However, the majority (71%) of UMRs that are shared between genotypes only exhibit partial overlaps suggesting that the boundaries between methylated and unmethylated DNA are dynamic. This instability is not solely due to sequence variation as these partially overlapping UMRs are frequently found within genomic regions that lack sequence variation. The ability to compare chromatin properties among individuals with structural variation enables pan-epigenome analyses to study the sources of variation for accessible chromatin and unmethylated DNA.
| S-EPMC8496265 | biostudies-literature
Project description:Human tumors are comprised of heterogeneous cell populations that display diverse molecular and phenotypic features. To examine the extent to which epigenetic differences contribute to intratumoral cellular heterogeneity, we have developed a high-throughput method, termed MAPit-patch. The method uses multiplexed amplification of targeted sequences from submicrogram quantities of genomic DNA followed by next generation bisulfite sequencing. This provides highly scalable and simultaneous mapping of chromatin accessibility and DNA methylation on single molecules at high resolution. Long sequencing reads from targeted regions maintain the structural integrity of epigenetic information and provide substantial depth of coverage, detecting for the first time minority subpopulations of epigenetic configurations formerly obscured by existing genome-wide and population-ensemble methodologies. Analyzing a cohort of 71 promoters of genes with exons commonly mutated in cancer, MAPit-patch uncovered several differentially accessible and methylated promoters that are associated with altered gene expression between neural stem cell (NSC) and glioblastoma (GBM) cell populations. In addition, considering each promoter individually, substantial epigenetic heterogeneity was observed across the sequenced molecules, indicating the presence of epigenetically distinct cellular subpopulations. At the divergent MLH1/EPM2AIP1 promoter, a locus with three well-defined, nucleosome-depleted regions (NDRs), a fraction of promoter copies with inaccessible chromatin was detected and enriched upon selection of temozolomide-tolerant GBM cells. These results illustrate the biological relevance of epigenetically distinct subpopulations that in part underlie the phenotypic heterogeneity of tumor cell populations. Furthermore, these findings show that alterations in chromatin accessibility without accompanying changes in DNA methylation may constitute a novel class of epigenetic biomarker.
| S-EPMC3912423 | biostudies-literature
Project description:Chromatin remodeling is important for the epigenetic reprogramming of human primordial germ cells. However, the comprehensive chromatin state has not yet been analyzed for human fetal germ cells (FGCs). Here we use nucleosome occupancy and methylation sequencing method to analyze both the genome-wide chromatin accessibility and DNA methylome at a series of crucial time points during fetal germ cell development in both human and mouse. We find 116 887 and 137 557 nucleosome-depleted regions (NDRs) in human and mouse FGCs, covering a large set of germline-specific and highly dynamic regulatory genomic elements, such as enhancers. Moreover, we find that the distal NDRs are enriched specifically for binding motifs of the pluripotency and germ cell master regulators such as NANOG, SOX17, AP2γ and OCT4 in human FGCs, indicating the existence of a delicate regulatory balance between pluripotency-related genes and germ cell-specific genes in human FGCs, and the functional significance of these genes for germ cell development in vivo. Our work offers a comprehensive and high-resolution roadmap for dissecting chromatin state transition dynamics during the epigenomic reprogramming of human and mouse FGCs.
| S-EPMC5339845 | biostudies-literature