Detection of Active Transposable Elements using Mobilome-seq on Poplar WT and ddm1 meristems in water stress conditions
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ABSTRACT:
ORGANISM(S): Populus tremula x Populus alba
PROVIDER: GSE147934 | GEO | 2023/03/22
REPOSITORIES: GEO
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Project description:The diversity of small RNA-directed DNA methylation (RdDM) mechanisms have been underestimated due to the nearly complete transcriptional silencing of transposable elements (TEs) in the wild-type reference strains of Arabidopsis thaliana. In plants mutant for the SWI/SNF histone remodeler DDM1, TEs are globally activated due to loss of genome wide heterochromatin condensation. Transcriptionally activated TEs go through additional non-canonical forms of RdDM that are dependent on RNA Polymerase II expression. However, the global targets of the non-canonical RdDM pathway have not been explored. In an attempt to identify and contrast the targets of canonical and expression-dependent non-canonical RdDM, we performed MethylC-seq of genome-wide DNA methylation patterns from several RdDM mutants in either the TE-silent or the TE-active (ddm1) contexts. Arabidopsis wildtype and twenty RdDM pathway mutants
2016-07-22 | E-GEOD-79746 | biostudies-arrayexpress
Project description:The diversity of small RNA-directed DNA methylation (RdDM) mechanisms have been underestimated due to the nearly complete transcriptional silencing of transposable elements (TEs) in the wt Col ecotype of Arabidopsis thaliana. In plants mutant for the SWI/SNF2 histone remodeler DDM1, TEs are globally activated due to loss of genome wide heterochromatin condensation. Activated TEs go through additional non-canonical forms of RdDM. However, the global targets of the non-canonical RdDM pathway are unidentified. In an attempt to identify and contrast the targets of canonical and non-canonical RdDM, we sequenced small RNAs from several RdDM mutants in either the TE-silent or the TE-active (ddm1) contexts. Examination of unopened flower bud small RNAs from wild type and various single or double mutant combinations, many of which have biological replicates. Small RNA sequences from wt Col, controls and other mutants shown in the study are available at GSE41755 and GSE57191.
2016-07-22 | E-GEOD-79780 | biostudies-arrayexpress
Project description:The diversity of small RNA-directed DNA methylation (RdDM) mechanisms have been underestimated due to the nearly complete transcriptional silencing of transposable elements (TEs) in the wt Col ecotype of Arabidopsis thaliana. In plants mutant for the SWI/SNF2 histone remodeler DDM1, TEs are globally activated due to loss of genome wide heterochromatin condensation. Activated TEs go through additional non-canonical forms of RdDM. However, the global targets of the non-canonical RdDM pathway are unidentified. In an attempt to identify and contrast the targets of canonical and non-canonical RdDM, we sequenced small RNAs from several RdDM mutants in either the TE-silent or the TE-active (ddm1) contexts.
2016-07-22 | GSE79780 | GEO
Project description:The diversity of small RNA-directed DNA methylation (RdDM) mechanisms have been underestimated due to the nearly complete transcriptional silencing of transposable elements (TEs) in the wild-type reference strains of Arabidopsis thaliana. In plants mutant for the SWI/SNF histone remodeler DDM1, TEs are globally activated due to loss of genome wide heterochromatin condensation. Transcriptionally activated TEs go through additional non-canonical forms of RdDM that are dependent on RNA Polymerase II expression. However, the global targets of the non-canonical RdDM pathway have not been explored. In an attempt to identify and contrast the targets of canonical and expression-dependent non-canonical RdDM, we performed MethylC-seq of genome-wide DNA methylation patterns from several RdDM mutants in either the TE-silent or the TE-active (ddm1) contexts.
2016-07-22 | GSE79746 | GEO
Project description:In this work, we studied function of rice DDM1 in coordinating DNA methylation, expression of small (sRNA) and long noncoding (lncRNA) RNAs, and nucleosome positioning by high throughput approaches.We show that the ddm1a/1b mutation resulted in ectopic CHH methylation of transposable elements (TE) and repeats. The ectopicCHH methylationwas dependent on DRM2, a DNA methyltransferase involved in sRNA-dependent DNA-methylation (RdDM). The ddm1a/1b mutation resulted in increases of heterochromatic sRNA but decreases of euchromatic sRNA production,induced expression of a set of developmentally regulated heterochromatic lncRNA , and increased nucleosome occupancy of TE-related or silent genes including heterochromatic lncRNA loci. In particular,DDM1-mediated repression ofCentromericRetrotransposons of Rice1 (CRR1) was essential for centromere function.
2018-06-06 | GSE108527 | GEO
Project description:Background: The majority of plant transposable elements (TEs) are found in a silenced state that is epigenetically propagated by the maintenance of symmetrical DNA methylation. TE methylation is established and reinforced by a mechanism of RNA-dependent DNA methylation, which is dependent on transcription of the PolIV RNA polymerase. Recently, a pathway has been described that initiates de novo DNA methylation dependent on components of the RNAi post-transcriptional silencing pathway, independent of PolIV. To define the function of this new pathway, we have focused on the RDR6 protein, which plays a central role in the pathway we refer to as RDR6-dependent RNA-directed DNA Methylation (RDR6-RdDM). Methods: We have sequenced total small RNAs from wild-type and three mutant genotypes: ddm1, ddm1/rdr6, and rdr6. Conclusions: We demonstrate that RDR6-RdDM utilizes 21 and 22 nucleotide siRNAs to de novo methylate actively transcribing TEs. In addition, we find that the RDR6-RdDM pathway functions in the efficient initiation and re-establishment of TE transcriptional silencing, while it is not necessary to maintain trans-generational epigenetic silencing. Examination of flower bud small RNAs from wild-type and 3 mutant genotypes
2013-04-11 | E-GEOD-41755 | biostudies-arrayexpress
Project description:The mutagenic activity of transposable elements (TEs) is suppressed by epigenetic silencing and small interfering RNAs (siRNAs), especially in gametes that would transmit transposed elements to the next generation. In pollen from the model plant Arabidopsis, we show that TEs are unexpectedly reactivated and transpose, but only in the pollen vegetative nucleus, which accompanies the sperm cells but does not provide DNA to the fertilized zygote. TE expression coincides with down-regulation of the heterochromatin remodeler DECREASE IN DNA METHYLATION 1 and of most TE siRNAs. However, 21 nucleotide siRNA from Athila retrotransposons is generated in pollen and accumulates in sperm, indicating that siRNA from TEs activated in the vegetative nucleus can target silencing in gametes. We propose a conserved role for reprogramming in germline companion cells, such as nurse cells in insects and vegetative nuclei in plants, to reveal intact TEs in the genome and regulate their activity in gametes. Mature pollen was collected from Columbia reference strain plants by vacuum filtration (Johnson-Brousseau and McCormick, 2004). DNA and RNA were isolated from a ddm1-2 plant in the Columbia reference background. Small RNAs of 19–28 nt were size selected by denaturing 15% PAGE, and cloned as in Brennecke et al. (2007). Additional details regarding the cloning of small RNAs are found in the Supplemental Data. The small RNA libraries were sequenced on Illumina 1G sequencer. The total number of sequences perfectly matching the Arabidopsis genome were as follows: WT inflorescence, 4,158,848 (2,286,133 unique); WT pollen, 1,034,665 (437,984 unique); ddm1 inflorescence, 4,098,772 (1,637,771 unique); and WT sperm, 760,651 (429,972 unique).
2014-09-04 | E-GEOD-61028 | biostudies-arrayexpress
Project description:The CMT2 and RNA-directed DNA methylation (RdDM) pathways have been proposed to separately maintain CHH methylation in specific regions of the Arabidopsis thaliana genome. Here, we show that dysfunction of the chromatin remodeller DDM1 causes hundreds of genomic regions to switch from CMT2-dependency to RdDM-dependency in DNA methylation. These converted loci are enriched at the edge regions of long transposable elements (TEs). Furthermore, we found that blocking the pathway switch by disrupting both DDM1 and RdDM causes strong reactivation of TEs and a burst of TE transposition in the first generation of mutant plants, indicating that the pathway conversion is critical to maintaining TE repression and protecting genomic stability. Our findings reveal the existence of a novel pathway conversion-based backup mechanism to guarantee the maintenance of DNA methylation and genome integrity.
2021-08-11 | GSE165877 | GEO
Project description:Methylation of histone H3 lysine 9 (H3K9me) and small RNA are associated with constitutively silent chromatin in diverse eukaryotes including plants. In plants, silent transposons are also marked by cytosine methylation, especially at non-CpG sites. The transposon-specific non-CpG methylation in plants is controlled by small RNA and H3K9me. Although it is often assumed that small RNA directs H3K9me, interaction between small RNA and H3K9me has not been directly shown in plants. We have previously shown that a mutation in a chromatin remodeling gene DDM1 (decrease in DNA methylation) induces a global decrease as well as local increase of cytosine methylation and accumulation of small RNA in a locus called BONSAI. Here we show that the de novo BONSAI methylation does not depend on RNAi but depends on H3K9me. Notably, in mutant of H3K9 methylase gene KRYPTONITE or H3K9me-dependent DNA methylase gene CHROMOMETHYALSE3, the ddm1-induced de novo cytosine methylation was abolished for all three contexts, CpG, CpHpG, and CpHpH. Furthermore, RNAi mutants showed strong developmental defects when combined with ddm1 mutation. Our results revealed unexpected interactions of epigenetic modifications, which could be conserved among diverse eukaryotes. comparison of DNA methylation between WT, 2G ddm1 (2 replications), 8G ddm1 (2 replications), and 8G ddm1 kyp
2011-12-25 | E-GEOD-34222 | biostudies-arrayexpress
Project description:mRNA levels in Wild-type versus ddm1 Arabidopsis thaliana seedlings and bolting plants. Features found to be significantly enriched for DNA methylation were determined. This SuperSeries is composed of the following subset Series: GSE1324: EV23+24 mRNA levels in Wild-type versus ddm1/+ backcross bolting Arabidopsis thaliana plants GSE1325: EV33+34 mRNA levels in Wild-type versus ddm1 Arabidopsis thaliana seedlings GSE1326: VC109+111 mRNA levels in Wild-type versus ddm1 Arabidopsis thaliana seedlings GSE1327: EV39+40 mRNA levels in Wild-type versus ddm1 Arabidopsis thaliana seedlings GSE1328: VC110+112 mRNA levels in Wild-type versus ddm1 bolting Arabidopsis thaliana plants Refer to individual Series
2010-06-09 | E-GEOD-1354 | biostudies-arrayexpress