MetaboLights MTBLS276 - GNPS "Diversity in DNA: Identification of methylated deoxyadenosines in higher eukaryotes"
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Dionex UltiMate 3000 RSLC System (Thermo)
ORGANISM(S): Blank Reference Compound Escherichia Coli Xenopus Laevis
SUBMITTER: 
Koziol
PROVIDER: MSV000082792 | GNPS | Tue Aug 07 16:26:00 BST 2018
REPOSITORIES: GNPS
Similar Datasets
Project description:Since the discovery that cytosine deoxynucleotides could be methylated (dC5m), not much is known in higher eukaryotes about modifications affecting other deoxynucleotides. Here, we now report that we detected N-6-methyl-deoxyadenosine (dA6m) not only in frog DNA, but also in other species including mouse and human. Our methylome analysis revealed that dA6m is widely distributed across the eukaryotic genome, is present in different cell types, but commonly depleted from gene exons. Since dA6m is a direct modification of DNA, it has the potential to generate a significant impact on different biological areas. Ultimately, our work shows that deoxycytidine modifications might not be the only ones in higher eukaryotes, suggesting that such direct DNA modifications might be more widespread than previously thought.
2015-11-16 | MTBLS276 | MetaboLights
Project description:Here, we report that we detected N-6-methyl-deoxyadenosine (dA6m) not only in frog DNA, but also in other species including mouse and humans. Our methylome analysis revealed that dA6m is widely distributed across the eukaryotic genome, and it is present in different cell types. dA6m is commonly depleted in gene exons, whilst it remains abundant in introns. Finally, we have identified the putative consensus sequence, where there is preferential methylation. Since dA6m is a direct modification of DNA, it has the potential to generate a significant impact on different biological areas. Ultimately, our work shows that deoxycytidine modifications might not be the only ones in higher eukaryotes, suggesting that DNA alterations might be more widespread than previously thought.
2015-11-12 | GSE74184 | GEO
Project description:DNA methylation is a widely conserved epigenetic modification that is established and maintained by the cooperative activity of DNA methyltransferases. While the complement of DNA methyltransferase genes can vary substantially between animal species, whole-genome methylation analyses have suggested that major features of animal methylomes are widely conserved. We have now used genome-scale bisulfite sequencing to analyze the methylome of the desert locust, Schistocerca gregaria, which represents an economically important pest with a high degree of phenotypic plasticity. Interestingly, in this system, DNA methylation appears to be both established and maintained by Dnmt1 methyltransferases, which distinguishes locusts from most other known organisms. Our results indicate that the S. gregaria methylome shares preferential methylation of CpG dinucleotides and exons with other animal methylomes. In contrast to other invertebrates, however, overall methylation levels were substantially higher and a significant fraction of transposons was methylated. Additionally, genes were densely methylated in a pronounced bimodal pattern, suggesting a role for DNA methylation in the regulation of locust gene expression. Altogether, our results uncover a unique pattern of genome methylation in locusts and also suggest that animal methylomes may be more diverse than previously thought. Whole exome methylation analysis of S. gregaria. Two samples were analyzed, one sample containing DNA from brain, one sample containing DNA from MTG. To date, there exists no sequenced genome of Schistocerca gregaria; thus, we could only map the data against an EST database (Locust2 EST project) representing the coding part of the genome.
2013-05-03 | E-GEOD-41214 | biostudies-arrayexpress
Project description:DNA methylation is a widely conserved epigenetic modification that is established and maintained by the cooperative activity of DNA methyltransferases. While the complement of DNA methyltransferase genes can vary substantially between animal species, whole-genome methylation analyses have suggested that major features of animal methylomes are widely conserved. We have now used genome-scale bisulfite sequencing to analyze the methylome of the desert locust, Schistocerca gregaria, which represents an economically important pest with a high degree of phenotypic plasticity. Interestingly, in this system, DNA methylation appears to be both established and maintained by Dnmt1 methyltransferases, which distinguishes locusts from most other known organisms. Our results indicate that the S. gregaria methylome shares preferential methylation of CpG dinucleotides and exons with other animal methylomes. In contrast to other invertebrates, however, overall methylation levels were substantially higher and a significant fraction of transposons was methylated. Additionally, genes were densely methylated in a pronounced bimodal pattern, suggesting a role for DNA methylation in the regulation of locust gene expression. Altogether, our results uncover a unique pattern of genome methylation in locusts and also suggest that animal methylomes may be more diverse than previously thought.
2013-05-03 | GSE41214 | GEO
Project description:Full title: Complex patterns of genome accessibility discriminate sites of PcG repression, H4K16 acetylation and replication initiation Histone modifications have been proposed to regulate gene expression in part by modulating DNA accessibility and higher-order chromatin structure. However, there is limited direct evidence to support structural differences between euchromatic and heterochromatic fibers in the nucleus. To ask how histone modifications relate to chromatin compaction, we measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint). In the Drosophila genome, we find that accessibility to DNA methylase is variable in a manner that relates to the differential distribution of active and repressive histone modifications. Active promoters are highly permissive to M.SssI activity, yet inactive chromosomal domains decorated with H3 lysine 27 trimethylation are least accessible providing in vivo evidence for Polycomb-mediated chromatin compaction. Conversely, DNA accessibility is increased at active chromosomal regions marked with H4 lysine 16 acetylation and at the dosage-compensated male X chromosome suggesting that Drosophila transcriptional dosage compensation is facilitated by more permissive chromatin structure. Interestingly early replicating chromosomal regions and sites of replication initiation show also higher accessibility linking temporal and spatial control of genome duplication to the structural organization of chromatin. In conclusion, using a novel protocol we generated a comprehensive view of DNA accessibility and uncover different levels of chromatin organization, which are delineated by distinct patterns of posttranslational histone modifications and replication. Keywords: cell type comparison, ChIP-chip, MeDIP-footprint, RNA-seq, ChIP-seq MeDIP-footprint and ChIP-chip: ChIP-chip was performed for H3K4me3, H3K36me2, H3K36me3, H3K27me3, and H3K9me2 in Kc cells. We measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint) in Kc and S2 cells. RNA-seq: cDNA from RNA from Drosophila Kc cells was sequenced using Illumina deep sequencing. Reads were mapped and the abundance of all transcripts was determined. ChIP-seq: PSC ChIP from Drosophila Kc cells was sequenced using Illumina deep sequencing in three lanes. Reads were mapped and the binding profile of PSC was determined.
2010-03-16 | E-GEOD-17697 | biostudies-arrayexpress
Project description:DNA methylation in murine WT ES cells was investigated by MBD domain mediated pull down of methylated DNA followed by chip analysis. For examination of 5hmC, hydroxymethylated DNA was enriched by Click-chemistry mediated pull down. Because of the lower amount of 5hmC, two different approached were adopted. The first approach was based on direct labeling of 5hmC DNA, and in the second method DNA was labeled after amplification with vitro transcription (IVT) . Microarray based hybridization (chip) analysis of epigenetic modifications, namely, 5mC and 5hmC for murine WT ES cells.
2014-10-21 | E-GEOD-51473 | biostudies-arrayexpress
Project description:Full title: Complex patterns of genome accessibility discriminate sites of PcG repression, H4K16 acetylation and replication initiation Histone modifications have been proposed to regulate gene expression in part by modulating DNA accessibility and higher-order chromatin structure. However, there is limited direct evidence to support structural differences between euchromatic and heterochromatic fibers in the nucleus. To ask how histone modifications relate to chromatin compaction, we measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint). In the Drosophila genome, we find that accessibility to DNA methylase is variable in a manner that relates to the differential distribution of active and repressive histone modifications. Active promoters are highly permissive to M.SssI activity, yet inactive chromosomal domains decorated with H3 lysine 27 trimethylation are least accessible providing in vivo evidence for Polycomb-mediated chromatin compaction. Conversely, DNA accessibility is increased at active chromosomal regions marked with H4 lysine 16 acetylation and at the dosage-compensated male X chromosome suggesting that Drosophila transcriptional dosage compensation is facilitated by more permissive chromatin structure. Interestingly early replicating chromosomal regions and sites of replication initiation show also higher accessibility linking temporal and spatial control of genome duplication to the structural organization of chromatin. In conclusion, using a novel protocol we generated a comprehensive view of DNA accessibility and uncover different levels of chromatin organization, which are delineated by distinct patterns of posttranslational histone modifications and replication. Keywords: cell type comparison, ChIP-chip, MeDIP-footprint, RNA-seq, ChIP-seq
2010-03-16 | GSE17697 | GEO
Project description:Epigenetic modification plays important roles in plant and animal development. DNA methylation can impact the transposable element (TE) silencing, gene imprinting and regulate gene expression.Through a genome-wide analysis, DNA methylation peaks were respectively characterized and mapped in maize embryo and endosperm genome. Distinct methylation level across maize embryo and endosperm was observed. The maize embryo genome contained more DNA methylation peaks than endosperm. However, the endosperm chloroplast genome contained more DNA methylation peaks to compare with the embryo chloroplast genome. DNA methylation regions were characterized and mapped in genome. More CG island (CGI) shore are methylated than CGI in maize suggested that DNA methylation level is not positively correlated with CpG density. The DNA methylation occurred more frequently in the promoter sequence and transcriptional termination region (TTR) than other regions of the genes. The result showed that 99% TEs we characterized are methylated in maize embryo, but some (34.8%) of them are not methylated in endosperm. Maize embryo and endosperm exhibit distinct pattern/level of methylation. The most differentially methylated two regions between embryo and endosperm are High CpG content promoters (HCPs) and high CpG content TTRs (HCTTRs). DNA methylation peaks distinction of mitochondria and chloroplast DNA were less than the nucleus DNA. Our results indicated that DNA methylation is associated with the gene silencing or gene activation in maize endosperm and embryo. Many genes involved in embryogenesis and seed development were found differentially methylated in embryo and endosperm. We found 17 endosperm-specific expressed imprinting genes were hypomethylated in endosperm and were hypermethylated in embryo. The expression of a maize DEMETER -like (DME-like) gene and MBD101 gene (MBD4 homolog) which direct bulk genome DNA demethylation were higher in endosperm than in embryo. These two genes may be associated with the distinct methylation level across maize embryo and endosperm.The methylomes of maize embryo and endosperm was obtained by MeDIP-seq method. The global mapping of maize embryo and endosperm methylation in this study broadened our knowledge of DNA methylation patterns in maize genome, and provided useful information for future studies on maize seed development and regulation of metabolic pathways in different seed tissues. Examination of DNA methylated modifications in 2 maize tissues.
2014-06-17 | E-GEOD-58549 | biostudies-arrayexpress
Project description:Transcription factors that bind small DNA motifs embedded in promoters play a central role in controlling gene expression. However, in addition to these elements, up to 70% of genes in higher eukaryotes also have high levels of non-methylated cytosine/guanine base pairs (CpGs) surrounding promoters and gene regulatory units. These features, called CpG islands, were identified over twenty years ago but there remains little mechanistic evidence to suggest how these enigmatic elements contribute to promoter function, with the exception that they are refractory to epigenetic silencing by DNA methylation. Here we show that CpG islands directly recruit the H3K36 specific lysine demethylase enzyme KDM2A. Genome wide analyses by ChIP-seq demonstrated a striking global association of KDM2A with CpG islands. Nucleation of KDM2A at these elements resulted in removal of H3K36 methylation creating CpG island chromatin that is uniquely depleted of this modification. KDM2A utilizes a zinc finger CxxC (ZF-CxxC) domain that specifically recognizes non-methylated CpG DNA and binding is blocked when the CpG DNA is methylated, thus constraining KDM2A to nonmethylated CpG islands. These data expose a remarkably straightforward mechanism through which KDM2A delineates a unique architecture that differentiates CpG island chromatin from bulk chromatin. Two cell lines were used in this study: a control line (LMP) with wildtype levels of KDM2A, and a KDM2A knockdown line (RNAi) in which KDM2A levels were depleted by approximately 60% using an shRNA-based approach. For each cell line, RNA was extracted from cells collected on two different dates (rep1 and rep2).
2010-05-27 | E-GEOD-21201 | biostudies-arrayexpress
Project description:Methylated DNA enrichment is a key step in a microarray based genome-wide methylation profiling study, and even for future high-throughput sequencing based methylome analysis. In order to evaluate the sensitivity and accuracy of methylated DNA enrichment, we investigated and optimized a number of important parameters to improve the performance of several enrichment assays, including differential methylation hybridization (DMH), microarray-based methylation assessment of single samples (MMASS), and methylated DNA immunoprecipitation (MeDIP). With advantages and disadvantages unique to each approach, we found that assays based on methylation-sensitive enzyme digestion and those based on immunoprecipitation detected different methylated DNA fragments, indicating that they are complementary in their relative ability to detect methylation differences. Our study provides the first comprehensive evaluation for widely used methodologies for methylated DNA enrichment, and could be helpful for developing a cost effective approach for DNA methylation profiling.
2010-01-22 | GSE19974 | GEO