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PROVIDER: PRJEB52387 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:DNA methylation is essential for silencing transposable elements and some genes in higher eukaryotes, implying that this modification must be tightly controlled. However, accidental changes in DNA methylation can be transmitted through mitosis, as in cancer, or meiosis, leading to epiallelic variation. Here, we demonstrate the existence of an efficient and faithful mechanism that protects against transgenerational loss of DNA methylation in the plant Arabidopsis. This process is specific to the subset of heavily methylated genomic repeats that are targeted by the RNAi machinery, and does not spread into flanking regions. Remethylation is often progressive over two to four sexual generations. This differential and incremental correction of epigenetic defects may preserve genome stability while increasing adaptive opportunities. 2 samples examined: wild type, and ddm1 mutant.
2009-02-02 | E-GEOD-13419 | biostudies-arrayexpress
Project description:DNA methylation is essential for silencing transposable elements and some genes in higher eukaryotes, implying that this modification must be tightly controlled. However, accidental changes in DNA methylation can be transmitted through mitosis, as in cancer, or meiosis, leading to epiallelic variation. Here, we demonstrate the existence of an efficient and faithful mechanism that protects against transgenerational loss of DNA methylation in the plant Arabidopsis. This process is specific to the subset of heavily methylated genomic repeats that are targeted by the RNAi machinery, and does not spread into flanking regions. Remethylation is often progressive over two to four sexual generations. This differential and incremental correction of epigenetic defects may preserve genome stability while increasing adaptive opportunities.
2009-02-02 | GSE13419 | GEO
Project description:The transgenerational stability of DNA methylation changes is important in setting up genomic DNA methylation patterns and in the formation and transmission of epialleles. It is generally assumed that DNA methylation changes at genomic regions targeted by the de novo, RNA-directed DNA methylation (RdDM) pathway are unstable. Here, we show that RdDM targets in Arabidopsis can be classified into two groups based on their transgenerational epiallele stability following restoration of NRPD1 function in nrpd1 mutant plants: remethylable loci and non-remethylable loci. Compared to the remethylable loci, non-remethylable ones contain higher levels of the euchromatic marks H3K4me3 and H3K18ac, which interferes with the recruitment of the RdDM molecular machinery and helps to recruit the DNA demethylase ROS1 to antagonize RdDM, respectively. Using targeted de-methylation by CRISPR/dCas9-TET1, we demonstrate that mCG and mCHG are memory marks required for targeting the RdDM machinery to remethylable loci. Our results show that histone and DNA methylation marks are critical in determining the capacity of RdDM target loci to form stable epialleles, and contribute to understanding the formation and transmission of epialleles.
2020-04-17 | GSE140566 | GEO
Project description:Active DNA demethylation controls transgenerational epigenetic stability
| PRJNA700573 | ENA
Project description:DNA methylation is a chemical modification of DNA that can be faithfully inherited across generations in flowering plant genomes. Failure to properly maintain DNA methylation can lead to epigenetic variation and transposon reactivation. Plant genomes are dynamic, spanning large ranges in size and there is an interplay between the genome and epigenome in shaping one another. To understand the variation in genomic patterning of DNA methylation between species, we compared methylomes of numerous diverse angiosperm species. By examining these variations in a phylogenetic context it becomes clear that there is extensive variation in mechanisms that govern gene body DNA methylation, euchromatic silencing of transposons and repeats, as well as silencing of heterochromatic transposons. Extensive variation is observed at all cytosine sequence contexts (CG, CHG and CHH, where H = A, C, T), with the Brassicaceae showing reduced CHG methylation levels and also reduced or loss of CG gene-body methylation. The Poaceae are characterized by a lack or reduction of heterochromatic CHH methylation and enrichment of CHH methylation in genic regions. Reduced CHH methylation levels are found in clonally propagated species, suggesting that these methods of propagation may alter the epigenomic landscape over time, in the absence of sexual reproduction. These results show that DNA methylation targeting pathways have diverged functionally and that extant DNA methylation patterns are likely a reflection of the evolutionary and life histories of plant species.
2016-09-02 | GSE79526 | GEO
Project description:DNA methylation is a chemical modification of DNA that can be faithfully inherited across generations in flowering plant genomes. Failure to properly maintain DNA methylation can lead to epigenetic variation and transposon reactivation. Plant genomes are dynamic, spanning large ranges in size and there is an interplay between the genome and epigenome in shaping one another. To understand the variation in genomic patterning of DNA methylation between species, we compared methylomes of numerous diverse angiosperm species. By examining these variations in a phylogenetic context it becomes clear that there is extensive variation in mechanisms that govern gene body DNA methylation, euchromatic silencing of transposons and repeats, as well as silencing of heterochromatic transposons. Extensive variation is observed at all cytosine sequence contexts (CG, CHG and CHH, where H = A, C, T), with the Brassicaceae showing reduced CHG methylation levels and also reduced or loss of CG gene-body methylation. The Poaceae are characterized by a lack or reduction of heterochromatic CHH methylation and enrichment of CHH methylation in genic regions. Reduced CHH methylation levels are found in clonally propagated species, suggesting that these methods of propagation may alter the epigenomic landscape over time, in the absence of sexual reproduction. These results show that DNA methylation targeting pathways have diverged functionally and that extant DNA methylation patterns are likely a reflection of the evolutionary and life histories of plant species. Bisulfite-seq of leaf tissue from plants representing diverse angiosperms. RNA-seq and small RNA-seq was performed on leaf tissue of a subset of the species.
2016-09-02 | E-GEOD-79526 | biostudies-arrayexpress
Project description:Ctcf heterozygous knockout mice are susceptible to neoplasia in a broad range of tissues, including lymphoma, endometrial cancer, and non-small cell lung cancer. Retention of the wild type Ctcf allele in these tumors establishes CTCF as a haploinsufficient tumor suppressor gene. Both human tumors and normal murine tissues with CTCF disruption are characterized by genome-wide differences in DNA methylation relative to CTCF wild type tissues, indicating even modest disruption of CTCF broadly destabilizes DNA methylation in vivo. This cross species functional analysis identifies CTCF as a commonly mutated tumor suppressor gene and establishes a central role for DNA methylation stability in tumor suppression. RRBS sequencing of transgenic Ctcf heterozygous mice and wild-type litter mate whole lung tissue.
2014-07-30 | E-GEOD-48975 | biostudies-arrayexpress
Project description:Improving plant stress response holds great agricultural potential. One promising, yet speculative, possibility is the formation of plant stress memory facilitating enhanced responses to recurring stress. One possibility is the involvement of environmentally-induced variation in reversible chromatin marks, such as DNA methylation, leading to the altered regulation of underlying genetic elements that promote enhanced stress tolerance. Such potential has spurred numerous investigations yielding conflicting results, thus it remains unclear whether robust stress-induced chromatin variation can encode plant stress memory conveying enhanced stress tolerance. Herein we investigate for the possibility of stress-induced alterations in DNA methylation to convey stress memory, both on mitotic and transgenerational timescales, such that previously stressed plants show improved stress tolerance with correlated alterations in DNA methylation at stress-responsive loci. We find that although the experience of stress may be stored mitotically, it does not appear to be transmitted meiotically and is independent of DNA methylation changes. Overall, the DNA methylome appears to be robust against stress-induced variation and is unlikely to contribute to any form of stress memory.
2017-10-03 | GSE94075 | GEO