High Resolution Mapping and Functional Analysis of the Methylome in Arabidopsis (polyA RNA)
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE5074 | GEO | 2006/08/17
SECONDARY ACCESSION(S): PRJNA95515
REPOSITORIES: GEO
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Project description:Cytosine DNA methylation is important for transposon silencing and epigenetic regulation of endogenous genes. Using a single-chip tiling microarray with 35 bp resolution, we carried out the first unbiased mapping of DNA methylation in the entire genome of the flowering plant Arabidopsis thaliana.Pericentromeric heterochromatin, repetitive sequences and regions producing small interfering RNAs were heavily methylated. Unexpectedly, over one third of expressed genes contained methylation within transcribed regions, whereas only ~5% of genes contained methylation within promoter regions. Interestingly, genes methylated in transcribed regions were highly expressed and constitutively active, whereas promoter-methylated genes showed a greater degree of tissue-specific expression. Analysis of several DNA methyltransferase mutants revealed widespread epigenetic regulation of protein-coding genes as well as non-coding RNA genes of unknown function. Keywords: whole genome profiling, DNA methylation, mCIP, MBD
2006-08-30 | GSE5094 | GEO
Project description:We present high-resolution maps of DNA methylation and H3K4 di- and tri-methylation of two entire chromosomes and two fully sequenced centromeres in rice shoots and cultured cells. Most transposable elements have highly methylated DNA but no H3K4 methylation whereas over half of protein-coding genes have both methylated DNA and di- and/or tri-methylated H3K4. Methylation of DNA but not H3K4 correlates with suppressed transcription. In contrast, if both DNA and H3K4 are methylated transcription is only slightly reduced. Transcriptional activity was positively correlated with H3K4Me3/H3K4Me2 within the gene body: genes with predominantly H3K4Me3 were actively transcribed whereas genes with predominantly H3K4Me2 were transcribed at moderate levels. Both H3K4Me2 and H3K4Me3 exhibited two peaks in long rice genes; a minor peak correlated with putative transcription start sites and a major peak downstream, implying possible roles in transcriptional initiation and elongation. Keywords: whole genome profiling, DNA methylation, ChIP
2008-01-04 | GSE9925 | GEO
Project description:Integration of the bacterial T-DNA into the plant genome by virulent agrobacteria causes crown gall development on many plant species. Plant tumor development shares fundamental similarities with mammalian cancer progression despite obvious differences in initiation of tumor development. For neoplastic growth in mammals, DNA methylation changes are known to be essential. The role of epigenetic modifications for plant tumor development is addressed here. Genome-wide comparison of methylation profiles of Arabidopsis crown galls and tumor-free tissue revealed 2,876 annotated genes that were affected by differential methylation. Thereof, 1,822 genes were hit by hypermethylated regions and 1,100 genes overlapped with hypomethylated regions (sum of hyper-and hypomethylated genes is higher than the number of affected genes because one gene may contain several differentially methylated regions [DMRs]). DMRs found to be methylated only in tumor-free tissue covered 275 kb of the genome, whereas those methylated only in crown galls total to 560 kb. Contrary to the globally hypermethylated tumor genome, promoter regions of protein coding genes appeared to be rather hypomethylated. In contrast, mammalian cancer cells are associated with global hypomethylation and local hypermethylation of gene promoters. In summary, while aberrant DNA methylation in mammals increases malignacy of the cancer phenotype, our results indicate that methylation events in the plant genome rather confine tumor growth. All 15,431 mCIP-enriched regions reported in the paper are contained in the supplementary BED files. mCIP of gDNA from crown galls vs. mCIP of gDNA from inflorescence stalks (3 biol. replicates each)
2013-02-18 | E-GEOD-37680 | biostudies-arrayexpress
Project description:Integration of the bacterial T-DNA into the plant genome by virulent agrobacteria causes crown gall development on many plant species. Plant tumor development shares fundamental similarities with mammalian cancer progression despite obvious differences in initiation of tumor development. For neoplastic growth in mammals, DNA methylation changes are known to be essential. The role of epigenetic modifications for plant tumor development is addressed here. Genome-wide comparison of methylation profiles of Arabidopsis crown galls and tumor-free tissue revealed 2,876 annotated genes that were affected by differential methylation. Thereof, 1,822 genes were hit by hypermethylated regions and 1,100 genes overlapped with hypomethylated regions (sum of hyper-and hypomethylated genes is higher than the number of affected genes because one gene may contain several differentially methylated regions [DMRs]). DMRs found to be methylated only in tumor-free tissue covered 275 kb of the genome, whereas those methylated only in crown galls total to 560 kb. Contrary to the globally hypermethylated tumor genome, promoter regions of protein coding genes appeared to be rather hypomethylated. In contrast, mammalian cancer cells are associated with global hypomethylation and local hypermethylation of gene promoters. In summary, while aberrant DNA methylation in mammals increases malignacy of the cancer phenotype, our results indicate that methylation events in the plant genome rather confine tumor growth. All 15,431 mCIP-enriched regions reported in the paper are contained in the supplementary BED files.
2013-02-18 | GSE37680 | 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:DNA (cytosine-5) methyltransferase 1 (DNMT1) is essential for mammalian development and maintenance of DNA methylation following DNA replication in cells. The DNA methylation process generates S-adenosyl-L-homocysteine, a strong inhibitor of DNMT1. Here we report that S-adenosylhomocysteine hydrolase (SAHH/AHCY), the only mammalian enzyme capable of hydrolyzing S-adenosyl-L-homocysteine binds to DNMT1 during DNA replication. SAHH activates DNMT1 in vitro and its overexpression in mammalian cells leads to hypermethylation of the genome, whereas its inhibition by adenosine periodate resulted in hypomethylation of the genome. Hypermethylation was consistent in both gene bodies and repetitive DNA elements leading to both down- and up-regulation of genes. Similarly, hypomethylation led to both up- and down-regulation of genes suggesting methylated regions influence gene expression either positively or negatively. Cells overexpressing SAHH specifically up-regulated metabolic pathway genes and down-regulated PPAR and MAPK signaling pathways genes. Therefore, we suggest that alteration of SAHH level in the cell leads to aberrant DNA methylation, altered metabolite levels and gene expression.
2018-06-06 | PXD006476 | Pride
Project description:Our data analysis unveils that differentially expressed long noncoding RNAs and some wrongly transcribed noncoding transcripts have potential DNA binding sites at promoters of differentially expressed or wrongly transcribed coding transcripts, gains and losses of differentially methylated DNA regions also occur at relevant sites, but less specifically. Moreover, both differentially expressed or wrongly transcribed transcripts and gains and losses of differentially methylated DNA regions show significant case-to-case variation.
2020-12-07 | GSE109203 | GEO
Project description:Our data analysis unveils that differentially expressed long noncoding RNAs and some wrongly transcribed noncoding transcripts have potential DNA binding sites at promoters of differentially expressed or wrongly transcribed coding transcripts, gains and losses of differentially methylated DNA regions also occur at relevant sites, but less specifically. Moreover, both differentially expressed or wrongly transcribed transcripts and gains and losses of differentially methylated DNA regions show significant case-to-case variation.
2020-12-07 | GSE109202 | GEO
Project description:Purpose: We characterized genome-wide DNA methylation profiles (methylome) in purified peripheral blood monocytes (PBMs) from 18 healthy postmenopausal Caucasian females aged 50-56 years. Methods: DNA methylome of Human Peripheral Blood Monocytes were generated by methylated DNA immunoprecipitation combined with high-throughput sequencing (MeDIP-seq), using Illumina GAIIx. The sequence reads that passed quality filters were analyzed using MEDIPS package. Targeted methylation validation analysis was performed by using MassARRAY EpiTYPER assays. Genome-wide gene expression profiles have been obtained for 7 of the 18 subjects by using Affymetrix 1.0 Human Exon ST arrays following the manufacturer's recommended protocols. Results: Using MeDIP-seq,a total of approximately 283 million reads were uniquely aligned to human genome (Build NCBI37, HG19), resulting in average ~16 million uniquely aligned high quality reads per sample. Distinct patterns were revealed at different genomic features. For instance, promoters were commonly (~58%) found to be unmethylated; whereas protein coding regions were largely (~84%) methylated. We found that approximately 24% CpG islands (CGIs) were highly methylated in PBMs. Further characterization of CGIs with respect to their relative locations to RefSeq genes revealed that the highly methylated CGIs were largely enriched (~89%) in CGIs located in gene bodies and intergenic regions. By integration of the methylome data with genome-wide PBM gene expression data, we found negative correlation between promoter methylation levels and gene transcription levels when comparing groups of genes with different expression levels, and this relationship was consistently observed across promoters with high to low CpG densities. Furthermore, we observed a modest but significant excess (permutation p<0.0001) of genes showing negative correlation between inter-individual promoter methylation and transcription levels, particularly for genes associated with CpG-rich promoters. Across the 18 individual PBM methylomes, we also identified genomic regions that were constitutively highly methylated in PBMs as well as regions showing large inter-individual variability. Conclusions: This study represents a comprehensive analysis of the PBM methylome and our data provides a valuable resource for future epigenomic and multi-omic studies exploring biological and disease-related regulatory mechanisms in PBMs. DNA methylome of human peripheral blood monocytes were generated by MeDIP-seq, using Illumina GAIIx.
2013-07-24 | E-GEOD-39604 | biostudies-arrayexpress
Project description:To further our understanding of the role of DNA methylation in development, Methylated DNA Immunoprecipitation (MeDIP) was used in conjunction with a NimbleGen promoter plus CpG island array to identify Tissue and Developmental Stage specific Differentially Methylated DNA Regions (T-DMRs and DS-DMRs) on a genome-wide basis. Four tissues (brain, heart, liver, and testis) from C57BL/6J mice were analyzed at three developmental stages (15 day embryo, E15; new born, NB; 12 week adult, AD). Almost 5,000 adult T-DMRs and 10,000 DS-DMRs were identified. Surprisingly, almost all DS-DMRs were tissue specific (i.e., methylated and ummenthylated in one or more non-overlapping tissues), indicating that the vast majority of unique sequence DNA methylation has tissue specificity. Also, many DS-DMRs were methylated at early development stages (E15 and NB) but unmethylated in adult, indicating “demethylation” has a prominent role in tissue differentiation. The pattern of DNA methylation in adult testis was dramatically different from somatic tissues in many aspects, mostly notably with a very strong bias of methylation in non-CpGi (CpG island) promoter regions (94%). Although the majority of T-DMRs and DS-DMRs tended to be in non-CpGi promoter regions, a relatively large number were also located in CpGi in promoter, intra-genic and inter-genic regions (>15% of all CpGi). Gene Ontology analysis of genes with methylation in non-CpGi promoters indicates enrichment of genes related to membrane proteins and G-protein coupled receptors. Our data also suggest regulatory roles of DNA methylation outside of promoter regions and in alternative promoter selection. Overall, our studies indicate that change in DNA methylation during development is a dynamic, widespread and tissue-specific process involving both DNA methylation and demethylation. Comparison of DNA methylation across 3 developmental stages (15 day embryo, newborn, and adult) for four tissues (brain, heart, liver and testis)
2010-12-31 | E-GEOD-21415 | biostudies-arrayexpress