MiRNAs trigger widespread epigenetically-activated siRNAs from transposons inM-BM- Arabidopsis (bisulfite-seq)
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
SUBMITTER: Kate Creasey
PROVIDER: E-GEOD-52346 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Methylation of chromosomal DNA in animals and plants is a fundamental mechanism of epigenetic regulation, and the maize genome, with its diverse complement of transposons and repeats, is a paradigm for transgenerational mechanisms such as paramutation and imprinting. We have determined the genome-wide cytosine methylation map of two maize inbred lines, B73 and Mo17, at high coverage and at single nucleotide resolution. Transposon methylation is highest in CG (65%) and CHG (50%) contexts (where H = A, C or T), while methylation in CHH (5%) contexts is guided by 24nt small interfering RNA (siRNA), and not by 21-22nt siRNA. We have found that CG (8%) methylation seems to deter insertion of Mutator transposons into exons, while CHH and CHG methylation at splice donor and acceptor sites strongly inhibits RNA splicing. Methylation differences between parents are inherited in recombinant inbred lines, but methylation switches, guided by siRNA, are widespread and persist for up to 8 generations. These differences influence splicing, and recurrent switching suggest that paramutation is much more common than previously supposed, and may contribute to heterosis. Our results provide a comprehensive high resolution resource for maize genome methylation, as well as a map of recurrent transgenerational epigenetic shifts (paramutation) in the two most commonly used inbred maize lines. Genome-wide cytosine methylation map in 2 maize strains by bisulfite sequencing, and RNA and small RNA profiles in the same tissue using Illumina platform.
2013-06-03 | E-GEOD-39232 | biostudies-arrayexpress
Project description:This is a total RNA-seq data set of two inbred lines of maize, B73 and Mo17, extracted from experiment E-GEOD-39232 (https://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-39232/). E-GEOD-39232 is a larger study which also studied the expression of small RNAs and genome-wide cytosine methylation pattern in the two cultivars using high-throughput sequencing methods. For total RNA-seq, three biological replicates were used per cultivar. E-GEOD-39232 was originally submitted to NCBI Gene Expression Omnibus under accession number GSE39232 (http://www.ncbi.nlm.nih.gov/projects/geo/query/acc.cgi?acc=GSE39232) and later imported to ArrayExpress as E-GEOD-39232.
2014-10-20 | E-MTAB-3028 | biostudies-arrayexpress
Project description:This study utilized next generation sequencing technology (RNA-Seq and BS-Seq) to examine the transcriptome and methylome of various tissues within sorghum plants with the ultimate goal of improving the Sorghum bicolor annotation We examined the mRNA of various Sorghum bicolor (BTx623) tissues (flowers, vegitative and floral meristems, embryos, roots and shoots) and bisulfite treated DNA from two root samples
2014-08-29 | E-GEOD-50464 | biostudies-arrayexpress
Project description:DNA methylation and nucleosome densities play a critical role in the regulation of gene expression. While much is known about the mechanisms of transcriptional control that are mediated by these, less is known about the degree to which they are tissue-specific. By comparing DNA methylation, nucleosome densities and transcriptional levels in different tissue types we can gain a clearer understanding of the extent to which these mechanisms influence gene expression in a tissue-specific manner. We compared DNA methylation in Arabidopsis shoots and roots and found extensive differences across the genome. We computed DNA methylation differences between roots and shoots at single cytosines and found that one in every 173 cytosines was differentially methylated. In addition, we compared DNA methylation with tissue-specific gene expression and nucleosome density measurements to identify associations between these. We also identified a group of genes that are strongly correlated with these epigenetic marks and are significantly differentially methylated between roots and shoots. These root-specific genes are part of the extensin family, and are preferentially methylated and have at least 10-fold higher expression and lower nucleosome density in roots relative to shoots. No replicates, two libraries for root methylation.
2014-02-11 | E-GEOD-52762 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-03-18 | E-GEOD-52952 | biostudies-arrayexpress
Project description:DNA methylation stabilizes developmentally programmed gene expression states. Aberrant methylation is associated with disease progression and is a common feature of cancer genomes. Presently, few methods enable quantitative, large-scale, single-base resolution mapping of DNA methylation states in desired regions of a complex mammalian genome. Here, we present an approach that combines array-based hybrid selection and massively parallel bisulfite sequencing to profile DNA methylation in genomic regions spanning hundreds of thousands of bases. This single molecule strategy enables methylation variable positions to be quantitatively examined with high sampling precision. Using bisulfite capture, we assessed methylation patterns across 324 randomly selected CpG islands (CGI) representing more than 25,000 CpG sites. A single lane of Illumina sequencing permitted methylation states to be definitively called for >90% of target sties. The accuracy of the hybrid-selection approach was verified using conventional bisulfite capillary sequencing of cloned PCR products amplified from a subset of the selected regions. This confirmed that even partially methylated states could be successfully called. A comparison of human primary and cancer cells revealed multiple differentially methylated regions. More than 25% of islands showed complex methylation patterns either with partial methylation states defining the entire CGI or with contrasting methylation states appearing in specific regional blocks within the island. We observed that transitions in methylation state often correlate with genomic landmarks, including transcriptional start sites and intron-exon junctions. Methylation, along with specific histone marks, was enriched in exonic regions, suggesting that chromatin states can foreshadow the content of mature mRNAs. Keywords: DNA methylation profiling by massively parallel sequencing Keywords: Epigenetics Targeted examination of DNA methylation in two human cell types by combining array capture and bisulfite sequencing. In addition, this study examined two histone marks in the breast tumor cell line MDA-MB-231.
2009-07-08 | E-GEOD-17001 | biostudies-arrayexpress
Project description:Bisulfite sequencing is a valuable tool for mapping the position of 5-methylcytosine in the genome at single base resolution. However, the associated chemistry renders the majority of DNA fragments unsequenceable, thus necessitating PCR amplification. Furthermore, bisulfite conversion generates an A,T-rich DNA library that leads to major PCR biases that may confound methylation analysis. Here we report a method that enables accurate methylation analysis, by rebuilding the damaged DNA library after bisulfite treatment. This recovery after bisulfite treatment (ReBuilT) approach enables PCR-free bisulfite sequencing from low nanogram quantities of genomic DNA. We applied the ReBuilT method for whole methylome analysis of the A,T rich genome of Plasmodium berghei. We demonstrate substantial improvements in coverage and the reduction of sequence-context biases as compared to classical methylome analysis. Our method will be widely applicable for accurate, quantitative methylation analysis, even for technically challenging genomes, and where limited sample DNA is available. From the same DNA sample we prepared 3 PCR-free Bisulfite-Seq replicates (ReBuilT) and 2 standard Bisulfite-Seq replicates (PCR-BS).
2016-03-16 | E-GEOD-65116 | biostudies-arrayexpress
Project description:DNA methylation is a conserved epigenetic gene regulation mechanism. DOMAINS REARRANGED METHYLTRANSFERASE (DRM) is a key de novo methyltransferase in plants, but how DRM acts mechanistically is poorly understood. Here, we report the crystal structure of the methyltransferase domain of tobacco DRM (NtDRM) and reveal a molecular basis for its rearranged structure. NtDRM forms a functional homo-dimer critical for catalytic activity. We also show that Arabidopsis DRM2 exists in complex with the siRNA effector ARGONAUTE4 (AGO4) and preferentially methylates one DNA strand, likely the strand acting as the template for non-coding Pol V RNA transcripts. This strand-biased DNA methylation is also positively correlated with strand-biased siRNA accumulation. These data suggest a model in which DRM2 is guided to target loci by AGO4-siRNA and involves base-pairing of associated siRNAs with nascent RNA transcripts. Whole-genome bisulfite sequencing was done for a wildtype line (ecotype Col) as well as various transgenic lines in a drm2 mutant background (ecotype Col). Each transgenic line expressed a version of the DRM2 protein that was either wildtype or carried induced mutations in order to test the function of various domains in the DRM2 protein. Two sets of whole-genome bisulfite were performed (130615 or 131216) and comparisons were mainly done within sets although comparisons can also be done between sets. The drm2 mutant methylome was also analyzed in this study using a previously published whole-genome bisulfite library (GSE39901).
2014-05-27 | E-GEOD-54944 | biostudies-arrayexpress
Project description:Using whole genome bisulfite sequencing to provide single-base resulution of DNA methylation status in rdm16ros1, ros1, nrpd1ros1 mutants and examine the effect of RDM16 on DNA methylation 4 samples examined: C24 wild type with RD29A-LUC transgene, rdm16ros1 double mutant, ros1 mutant, nrpd1ros1 mutant (all in C24 background with RD29A-LUC transgene)
2013-09-27 | E-GEOD-44417 | biostudies-arrayexpress
Project description:In Arabidopsis, CHG DNA methylation is controlled by the H3K9 methylation mark through a self-reinforcing loop between DNA methyltransferase CHROMOMETHYLASE3 (CMT3) and H3K9 histone methyltransferase KRYPTONITE/SUVH4 (KYP). We report on the structure of KYP in complex with methylated DNA, substrate H3 peptide and cofactor SAH, thereby defining the spatial positioning of the SRA domain relative to the SET domain. The methylated DNA is bound by the SRA domain with the 5mC flipped out of the DNA, while the H3(1-15) peptide substrate binds between the SET and post-SET domains, with the epsilon-ammonium of K9 positioned adjacent to bound SAH. These structural insights complemented by in vivo functional data on key mutants of residues lining the 5mC and H3K9-binding pockets within KYP, establish how methylated DNA recruits KYP to the histone substrate. Together, the structures of KYP and previously reported CMT3 complexes provide insights into molecular mechanisms linking DNA and histone methylation. Plants homozygous for null mutations in the KRYPTONITE H3K9 methyltransferase were stably transformed with transgenes encoding the wildtype KYP protein or transgenes carrying induced point mutations in the KYP active site. The resulting lines were assayed for DNA methylation by whole-genome bisulfite sequencing to learn the efficiency with which wildtype and mutant versions of the KYP protein could restore DNA methylation lost in a kyp mutant. Samples 7 and 8 were run as single Illumina lanes and as such were compared to a previous Col sample (GSM881756), this Col sample was realigned to the TAIR10 genome for this study and as such updated processed files are available with this submission. These samples were used to define kyp mutant CHG context DMRs that were complemented upon introduction of the wildtype KYP protein. Samples 1-6 were run as multiplexed samples and were used to assay the degree of complementation for various point mutants. All plants are in the Col ecotype background.
2014-08-01 | E-GEOD-57963 | biostudies-arrayexpress