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Genome-wide demethylation of Arabidopsis endosperm.

ABSTRACT: Parent-of-origin-specific (imprinted) gene expression is regulated in Arabidopsis thaliana endosperm by cytosine demethylation of the maternal genome mediated by the DNA glycosylase DEMETER, but the extent of the methylation changes is not known. Here, we show that virtually the entire endosperm genome is demethylated, coupled with extensive local non-CG hypermethylation of small interfering RNA-targeted sequences. Mutation of DEMETER partially restores endosperm CG methylation to levels found in other tissues, indicating that CG demethylation is specific to maternal sequences. Endosperm demethylation is accompanied by CHH hypermethylation of embryo transposable elements. Our findings demonstrate extensive reconfiguration of the endosperm methylation landscape that likely reinforces transposon silencing in the embryo.

SUBMITTER: Hsieh TF

PROVIDER: S-EPMC4044190 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature

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Genome-wide demethylation of Arabidopsis endosperm.

Hsieh Tzung-Fu TF Ibarra Christian A CA Silva Pedro P Zemach Assaf A Eshed-Williams Leor L Fischer Robert L RL Zilberman Daniel D

Science (New York, N.Y.) 20090601 5933

Parent-of-origin-specific (imprinted) gene expression is regulated in Arabidopsis thaliana endosperm by cytosine demethylation of the maternal genome mediated by the DNA glycosylase DEMETER, but the extent of the methylation changes is not known. Here, we show that virtually the entire endosperm genome is demethylated, coupled with extensive local non-CG hypermethylation of small interfering RNA-targeted sequences. Mutation of DEMETER partially restores endosperm CG methylation to levels found i ...[more]

PMID: 19520962

Similar Datasets

Genome-wide demethylation of Arabidopsis endosperm

Project description:Parent-of-origin-specific (imprinted) gene expression is regulated in Arabidopsis thaliana endosperm by cytosine demethylation of the maternal genome mediated by the DNA glycosylase DEMETER, but the extent of the methylation changes is not known. Here we show that virtually the entire endosperm genome is demethylated, coupled with extensive local non-CG hypermethylation of siRNA-targeted sequences. Mutation of DEMETER partially restores endosperm CG methylation to levels found in other tissues, indicating that CG demethylation is specific to maternal sequences. Endosperm demethylation is accompanied by CHH hypermethylation of embryo transposable elements. Our findings demonstrate extensive reconfiguration of the endosperm methylation landscape that likely reinforces transposon silencing in the embryo. Keywords: Epigenetics; bisulfite sequencing

2009-06-16 | GSE15922 | GEO

Genome-wide demethylation of Arabidopsis endosperm

2009-06-16 | E-GEOD-15922 | biostudies-arrayexpress

DNA demethylation in the Arabidopsis genome.

Project description:Cytosine DNA methylation is considered to be a stable epigenetic mark, but active demethylation has been observed in both plants and animals. In Arabidopsis thaliana, DNA glycosylases of the DEMETER (DME) family remove methylcytosines from DNA. Demethylation by DME is necessary for genomic imprinting, and demethylation by a related protein, REPRESSOR OF SILENCING1, prevents gene silencing in a transgenic background. However, the extent and function of demethylation by DEMETER-LIKE (DML) proteins in WT plants is not known. Using genome-tiling microarrays, we mapped DNA methylation in mutant and WT plants and identified 179 loci actively demethylated by DML enzymes. Mutations in DML genes lead to locus-specific DNA hypermethylation. Reintroducing WT DML genes restores most loci to the normal pattern of methylation, although at some loci, hypermethylated epialleles persist. Of loci demethylated by DML enzymes, >80% are near or overlap genes. Genic demethylation by DML enzymes primarily occurs at the 5' and 3' ends, a pattern opposite to the overall distribution of WT DNA methylation. Our results show that demethylation by DML DNA glycosylases edits the patterns of DNA methylation within the Arabidopsis genome to protect genes from potentially deleterious methylation.

| S-EPMC1847597 | biostudies-literature

DNA demethylation affects imprinted gene expression in maize endosperm.

Project description:BackgroundDNA demethylation occurs in many species and is involved in diverse biological processes. However, the occurrence and role of DNA demethylation in maize remain unknown.ResultsWe analyze loss-of-function mutants of two major genes encoding DNA demethylases. No significant change in DNA methylation has been detected in these mutants. However, we detect increased DNA methylation levels in the mutants around genes and some transposons. The increase in DNA methylation is accompanied by alteration in gene expression, with a tendency to show downregulation, especially for the genes that are preferentially expressed in endosperm. Imprinted expression of both maternally and paternally expressed genes changes in F1 hybrid with the mutant as female and the wild-type as male parental line, but not in the reciprocal hybrid. This alteration in gene expression is accompanied by allele-specific DNA methylation differences, suggesting that removal of DNA methylation of the maternal allele is required for the proper expression of these imprinted genes. Finally, we demonstrate that hypermethylation in the double mutant is associated with reduced binding of transcription factor to its target, and altered gene expression.ConclusionsOur results suggest that active removal of DNA methylation is important for transcription factor binding and proper gene expression in maize endosperm.

| S-EPMC8905802 | biostudies-literature

Genome-wide bisulphite sequencing of Arabidopsis thaliana embryo and endosperm

Project description:The DEMETER (DME) DNA glycosylase mediates genome-wide DNA demethylation and is required for endosperm genomic imprinting and embryo viability. Targets of DME-demethylation are small, AT-rich transposons and boundaries of large heterochromatic transposons, but how DME interacts with chromatin is unclear. To investigate the interaction between DME and chromatin, we analyzed DNA methylation in Arabidopsis seeds and pollen deficient in the chromatin remodeler FAcilitates Chromatin Transactions (FACT) complex. We find that FACT co-localizes with nuclear DME, and is required for DME activity in chromatin domains with high nucleosome occupancy and histone modifications associated with heterochromatin, which comprise over half of DME target loci. We also demonstrate that heterochromatin-associated linker histone H1 mediates the requirement for FACT at a subset of DME-target loci. However, FACT is not required for DME demethylation of targets in euchromatic regions. Thus, chromatin structure determines the degree to which FACT facilitates access of DME to its targets.

2018-04-17 | GSE105000 | GEO

DPPA3 facilitates genome-wide DNA demethylation in mouse primordial germ cells.

Project description:BackgroundGenome-wide DNA demethylation occurs in mammalian primordial germ cells (PGCs) as part of the epigenetic reprogramming important for gametogenesis and resetting the epigenetic information for totipotency. Dppa3 (also known as Stella or Pgc7) is highly expressed in mouse PGCs and oocytes and encodes a factor essential for female fertility. It prevents excessive DNA methylation in oocytes and ensures proper gene expression in preimplantation embryos: however, its role in PGCs is largely unexplored. In the present study, we investigated whether or not DPPA3 has an impact on CG methylation/demethylation in mouse PGCs.ResultsWe show that DPPA3 plays a role in genome-wide demethylation in PGCs even before sex differentiation. Dppa3 knockout female PGCs show aberrant hypermethylation, most predominantly at H3K9me3-marked retrotransposons, which persists up to the fully-grown oocyte stage. DPPA3 works downstream of PRDM14, a master regulator of epigenetic reprogramming in embryonic stem cells and PGCs, and independently of TET1, an enzyme that hydroxylates 5-methylcytosine.ConclusionsThe results suggest that DPPA3 facilitates DNA demethylation through a replication-coupled passive mechanism in PGCs. Our study identifies DPPA3 as a novel epigenetic reprogramming factor in mouse PGCs.

| S-EPMC10996186 | biostudies-literature

Genome-wide view of natural antisense transcripts in Arabidopsis thaliana.

Project description:Natural antisense transcripts (NATs) are endogenous transcripts that can form double-stranded RNA structures. Many protein-coding genes (PCs) and non-protein-coding genes (NPCs) tend to form cis-NATs and trans-NATs, respectively. In this work, we identified 4,080 cis-NATs and 2,491 trans-NATs genome-widely in Arabidopsis. Of these, 5,385 NAT-siRNAs were detected from the small RNA sequencing data. NAT-siRNAs are typically 21nt, and are processed by Dicer-like 1 (DCL1)/DCL2 and RDR6 and function in epigenetically activated situations, or 24nt, suggesting these are processed by DCL3 and RDR2 and function in environment stress. NAT-siRNAs are significantly derived from PC/PC pairs of trans-NATs and NPC/NPC pairs of cis-NATs. Furthermore, NAT pair genes typically have similar pattern of epigenetic status. Cis-NATs tend to be marked by euchromatic modifications, whereas trans-NATs tend to be marked by heterochromatic modifications.

| S-EPMC4463847 | biostudies-other

Loss of linker histone H1 in the maternal genome influences DEMETER-mediated demethylation and affects the endosperm DNA methylation landscape.

Project description:The Arabidopsis DEMETER (DME) DNA glycosylase demethylates the central cell genome prior to fertilization. This epigenetic reconfiguration of the female gamete companion cell establishes gene imprinting in the endosperm and is essential for seed viability. DME demethylates small and genic-flanking transposons as well as intergenic and heterochromatin sequences, but how DME is recruited to these loci remains unknown. H1.2 was identified as a DME-interacting protein in a yeast two-hybrid screen, and maternal genome H1 loss affects DNA methylation and expression of selected imprinted genes in the endosperm. Yet, the extent to which H1 influences DME demethylation and gene imprinting in the Arabidopsis endosperm has not been investigated. Here, we showed that without the maternal linker histones, DME-mediated demethylation is facilitated, particularly in the heterochromatin regions, indicating that H1-bound heterochromatins are barriers for DME demethylation. Loss of H1 in the maternal genome has a very limited effect on gene transcription or gene imprinting regulation in the endosperm; however, it variably influences euchromatin TE methylation and causes a slight hypermethylation and a reduced expression in selected imprinted genes. We conclude that loss of maternal H1 indirectly influences DME-mediated demethylation and endosperm DNA methylation landscape but does not appear to affect endosperm gene transcription and overall imprinting regulation.

| S-EPMC9813442 | biostudies-literature

Genome-wide screening and analysis of imprinted genes in rapeseed (Brassica napus L.) endosperm.

Project description:Species-specific genomic imprinting is an epigenetic phenomenon leading to parent-of-origin-specific differential expression of maternally and paternally inherited alleles. To date, no studies of imprinting have been reported in rapeseed, a tetraploid species. Here, we analysed global patterns of allelic gene expression in developing rapeseed endosperms from reciprocal crosses between inbred lines YN171 and 93275. A total of 183 imprinted genes, consisting of 167 maternal expressed genes (MEGs) and 16 paternal expressed genes (PEGs), were identified from 14,394 genes found to harbour diagnostic SNPs between the parental lines. Some imprinted genes were validated in different endosperm stages and other parental combinations by RT-PCR analysis. A clear clustering of imprinted genes throughout the rapeseed genome was identified, which was different from most other plants. Methylation analysis of 104 out of the 183 imprinted genes showed that 11 genes (7 MEGs and 4 PEGs) harboured differentially methylated regions (DMRs). Unexpectedly, only 1 MEG out of these 11 genes had a DMR that exhibited high CG methylation rate in paternal allele and had big difference between parent alleles. These results extend our understanding of gene imprinting in plants and provide potential avenues for further research in imprinted genes.

| S-EPMC6289790 | biostudies-literature

Genome wide analysis of Arabidopsis core promoters.

Project description:BackgroundCore promoters are the gene regulatory regions most proximal to the transcription start site (TSS), central to the formation of pre-initiation complexes and for combinatorial gene regulation. The DNA elements required for core promoter function in plants are poorly understood. To establish the sequence motifs that characterize plant core promoters and to compare them to the corresponding sequences in animals, we took advantage of available full-length cDNAs (FL-cDNAs) and predicted upstream regulatory sequences to carry out the analysis of 12,749 Arabidopsis core promoters.ResultsUsing a combination of expectation maximization and Gibbs sampling methods, we identified several motifs overrepresented in Arabidopsis core promoters. One of them corresponded to the TATA element, for which an in-depth analysis resulted in the generation of robust TATA Nucleotide Frequency Matrices (NFMs) capable of predicting Arabidopsis TATA elements with a high degree of confidence. We established that approximately 29% of all Arabidopsis promoters contain TATA motifs, clustered around position -32 with respect to the TSS. The presence of TATA elements was associated with genes represented more frequently in EST collections and with shorter 5' UTRs. No cis-elements were found over-represented in TATA-less, compared to TATA-containing promoters.ConclusionOur studies provide a first genome-wide illustration of the composition and structure of core Arabidopsis promoters. The percentage of TATA-containing promoters is much lower than commonly recognized, yet comparable to the number of Drosophila promoters containing a TATA element. Although several other DNA elements were identified as over-represented in Arabidopsis promoters, they are present in only a small fraction of the genes and they represent elements not previously described in animals, suggesting a distinct architecture of the core promoters of plant and animal genes.

| S-EPMC554773 | biostudies-literature

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