Genome-wide demethylation of Arabidopsis endosperm
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE15922 | GEO | 2009/06/16
SECONDARY ACCESSION(S): PRJNA116929
REPOSITORIES: GEO
Similar Datasets
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 Examination of DNA methylation in four Arabidopsis tissues Description of processed data and raw data file contents can be found in the attached README.txt file
2009-06-16 | E-GEOD-15922 | biostudies-arrayexpress
Project description:Cytosine methylation is a DNA modification with important regulatory functions in eukaryotes. In flowering plants, sexual reproduction is accompanied by extensive DNA demethylation, which is required for proper gene expression in the endosperm, a nutritive extra-embryonic seed tissue. Endosperm arises from a fusion of a sperm cell carried in the pollen and a female central cell. Endosperm DNA demethylation is observed specifically on the chromosomes inherited from the central cell in Arabidopsis thaliana, rice and maize, and requires the DEMETER DNA demethylase in Arabidopsis. DEMETER is expressed in the central cell prior to fertilization, suggesting that endosperm demethylation patterns are inherited from the central cell. Downregulation of the MET1 DNA methyltransferase has also been proposed to contribute to demethylation in the central cell. However, with the exception of three maize genes, central cell DNA methylation has not been directly measured, leaving the origin and mechanism of endosperm demethylation uncertain. Here, we report genome-wide analysis of DNA methylation in the central cells of Arabidopsis and rice, as well as in rice egg cells. We find that DNA demethylation in both species is initiated in central cells, which requires DEMETER in Arabidopsis. However, we do not observe a global reduction of CG methylation that would be indicative of lowered MET1 activity; on the contrary, CG methylation efficiency is elevated in female gametes compared to non-sexual tissues. Our results demonstrate that locus-specific, active DNA demethylation in the central cell is the origin of maternal chromosome hypomethylation in the endosperm.
2016-11-30 | GSE89789 | GEO
Project description:The Arabidopsis thaliana central cell, the companion cell of the egg, undergoes DNA demethylation prior to fertilization, but the targeting preferences and biological significance of this process remain unclear. Here, we show that active DNA demethylation mediated by the DEMETER DNA glycosylase accounts for all of the demethylation in the central cell, and preferentially targets small, AT-rich and nucleosome-depleted transposable elements. The vegetative cell, the companion cell of sperm, also undergoes DEMETER-dependent demethylation of similar sequences, and lack of DEMETER in vegetative cells causes reduced small RNA-directed DNA methylation of transposons in sperm. Our results demonstrate that demethylation in companion cells reinforces transposon methylation in plant gametes, thereby assuring stable silencing of transposable elements across generations Examination of DNA methylation in Arabidopsis endosperm, embryo, and pollen
2012-09-21 | E-GEOD-38935 | biostudies-arrayexpress
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 target 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 how H1 influences DME demethylation and gene imprinting in the Arabidopsis endosperm has not been investigated. Here, we showed that unlike in the vegetative cell, both canonical histone H1 variants are present in the central cell. Our endosperm methylome analysis revealed that without the maternal linker histones, DME-mediated demethylation is facilitated, particularly in the heterochromatin regions, indicating that H1-containing nucleosomes 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.
2022-11-11 | GSE217277 | GEO
Project description:Some flowering plant and vertebrate genes are expressed primarily or exclusively from either the maternal or paternal allele, a phenomenon called genomic imprinting. Flowering plant imprinted gene expression has been described primarily in endosperm, a terminal nutritive tissue consumed by the embryo during seed development or after germination. Imprinted expression in Arabidopsis thaliana endosperm is orchestrated by differences in cytosine DNA methylation between the paternal and maternal genomes, as well as by Polycomb group (PcG) proteins. Currently only eleven imprinted Arabidopsis genes are known. Here we use extensive sequencing of cDNA libraries to identify many new paternally and maternally imprinted genes in A. thaliana endosperm, including transcription factors, proteins involved in hormone signaling, and epigenetic regulators. The imprinted status of many maternally-expressed genes is not altered by mutations in the DNA-demethylating glycosylase DEMETER, the DNA methyltransferase MET1 or the core PcG protein FIE, indicating that these genes are regulated by novel mechanisms or deposited from maternal tissues. We did not find any imprinted genes in the embryo. Our results demonstrate that imprinted gene expression, particularly from the maternal genome, is an extensive, mechanistically complex phenomenon that likely affects multiple aspects of seed development. Epigenetics Examination of genomic imprinting in Arabidopsis endosperm
2011-03-10 | E-GEOD-24644 | biostudies-arrayexpress
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: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.
2014-06-17 | GSE58549 | GEO
Project description:Some flowering plant and vertebrate genes are expressed primarily or exclusively from either the maternal or paternal allele, a phenomenon called genomic imprinting. Flowering plant imprinted gene expression has been described primarily in endosperm, a terminal nutritive tissue consumed by the embryo during seed development or after germination. Imprinted expression in Arabidopsis thaliana endosperm is orchestrated by differences in cytosine DNA methylation between the paternal and maternal genomes, as well as by Polycomb group (PcG) proteins. Currently only eleven imprinted Arabidopsis genes are known. Here we use extensive sequencing of cDNA libraries to identify many new paternally and maternally imprinted genes in A. thaliana endosperm, including transcription factors, proteins involved in hormone signaling, and epigenetic regulators. The imprinted status of many maternally-expressed genes is not altered by mutations in the DNA-demethylating glycosylase DEMETER, the DNA methyltransferase MET1 or the core PcG protein FIE, indicating that these genes are regulated by novel mechanisms or deposited from maternal tissues. We did not find any imprinted genes in the embryo. Our results demonstrate that imprinted gene expression, particularly from the maternal genome, is an extensive, mechanistically complex phenomenon that likely affects multiple aspects of seed development. Epigenetics
2011-03-10 | GSE24644 | GEO
Project description:TheArabidopsisDEMETER (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 target 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 how H1 influences DME demethylation and gene imprinting in theArabidopsisendosperm has not been investigated. Here, we showed that unlike in the vegetative cell, both canonical histone H1 variants are present in the central cell. Our endosperm methylome analysis revealed that without the maternal linker histones, DME-mediated demethylation is facilitated, particularly in the heterochromatin regions, indicating that H1-containing nucleosomes 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.
2022-11-11 | GSE217278 | GEO
Project description:Cytosine methylation silences transposable elements in plants, vertebrates and fungi, but also regulates gene expression1. Plant methylation is catalyzed by three families of enzymes, each with a preferred sequence context: CG, CHG (H = A, C or T) and CHH, with CHH methylation targeted by the RNA interference (RNAi) pathway2. Arabidopsis thaliana endosperm, a placenta-like tissue that nourishes the embryo, is globally hypomethylated in the CG context while retaining high non-CG methylation3. Global methylation dynamics in seeds of cereal crops that provide the bulk of human nutrition remain unknown. Here we show that rice endosperm DNA is hypomethylated in all sequence contexts. Non-CG methylation is reduced evenly across the genome, while CG hypomethylation is localized. CHH methylation of small transposable elements is increased in embryos, suggesting that endosperm demethylation enhances transposon silencing. Genes preferentially expressed in endosperm, including those coding for major storage proteins and starch synthesizing enzymes, are frequently hypomethylated in endosperm, indicating that DNA methylation is a crucial regulator of rice endosperm biogenesis. Our data demonstrate that genome-wide reshaping of seed DNA methylation is conserved among angiosperms and has a profound effect on gene expression in cereal crops. Keywords: Epigenetics Examination of DNA methylation in rice
2010-11-01 | E-GEOD-22591 | biostudies-arrayexpress