Loss of Karma transposon methylation underlies oil palm somaclonal mantling
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ABSTRACT: The oil palm fruit abnormality, mantled, is a somaclonal variant arising from tissue culture that drastically reduces yield, and has largely halted efforts to clone elite hybrids for breeding and oil production. Widely regarded as epigenetic, mantling had defied explanation, and has become an icon of unsustainability in environmentally sensitive tropical plantation crops. We identified the MANTLED gene using Epigenome Wide Association analysis of genetically identical palms from multiple clonal lineages. Hypomethylation of a LINE retrotransposon related to rice Karma, found in the intron of the homeotic gene DEFICIENS, is common to all mantled clones and is correlated with alternative splicing and loss of small RNA. DNA methylation is regained in spontaneous revertants accounting for non-Medelian inheritance of the Good Karma and Bad Karma epialleles. Thus epigenetic regulation of transposable elements results in somaclonal variation and provides a means to cull mantled nursery palms before committing limiting plantation resources to clonal propagation. DNA methylation profiling was performed using the McrBC DNA methylation dependent fractionation and microarray hybridization method as described in Lippman, Z., Gendrel, A. V., Colot, V. & Martienssen, R. Profiling DNA methylation patterns using genomic tiling microarrays. Nat Methods 2, 219-224 (2005). DNA methylation profiling was performed on 54 parthenocarpic mantled ramet, 43 normal ramet and 1 ortet adult leaf samples. For each sample, two independent fractionations of total genomic DNA and DNA methylation-depleted DNA were performed. Each total DNA/methylation-depleted DNA pair was differentially labeled and hydrized to a custon Nimblegen microarray in a dye-swapped design (4 array hybridizations per sample).
Project description:The oil palm fruit abnormality, mantled, is a somaclonal variant arising from tissue culture that drastically reduces yield, and has largely halted efforts to clone elite hybrids for breeding and oil production. Widely regarded as epigenetic, mantling had defied explanation, and has become an icon of unsustainability in environmentally sensitive tropical plantation crops. We identified the MANTLED gene using Epigenome Wide Association analysis of genetically identical palms from multiple clonal lineages. Hypomethylation of a LINE retrotransposon related to rice Karma, found in the intron of the homeotic gene DEFICIENS, is common to all mantled clones and is correlated with alternative splicing and loss of small RNA. DNA methylation is regained in spontaneous revertants accounting for non-Medelian inheritance of the Good Karma and Bad Karma epialleles. Thus epigenetic regulation of transposable elements results in somaclonal variation and provides a means to cull mantled nursery palms before committing limiting plantation resources to clonal propagation. DNA methylation profiling was performed using the McrBC DNA methylation dependent fractionation and microarray hybridization method as described in Lippman, Z., Gendrel, A. V., Colot, V. & Martienssen, R. Profiling DNA methylation patterns using genomic tiling microarrays. Nat Methods 2, 219-224 (2005).
Project description:Autotransplantation of in vitro proliferated spermatogonial stem cells (SSCs) has been advocated as a way to restore fertility in childhood cancer survivors. In this study we determined the effects of cell culture on DNA methylation patterning in human SSCs, to evaluate the safety of future clinical application of SSC autotransplantation. Bisulfite converted DNA of 34 human spermatogonial stem cell samples, 4 sperm samples and 3 seminoma samples were hybridized to Illumina Infinium 450k Human Methylation Beadchips
Project description:Increasing evidence has demonstrated that epigenetic factors can profoundly influence gene expression and, in turn, influence resistance or susceptibility to disease. Epigenetic drugs, such as histone deacetylase (HDAC) inhibitors, are finding their way into clinical practice, although their exact mechanisms of action are unclear. To identify mechanisms associated with HDAC inhibition, we performed microarray analysis on brain and muscle samples treated with the HDAC1/3-targeting inhibitor, HDACi 4b. Pathways analyses of microarray datasets implicate DNA methylation as significantly associated with HDAC inhibition. Further assessment of DNA methylation changes elicited by HDACi 4b in human fibroblasts from normal controls and patients with Huntington's disease (HD) using the Infinium HumanMethylation450 BeadChip revealed a limited, but overlapping, subset of methylated CpG sites that were altered by HDAC inhibition in both normal and HD cells. Among the altered loci of Y chromosome-linked genes, KDM5D, which encodes Lys (K)-specific demethylase 5D, showed increased methylation at several CpG sites in both normal and HD cells, as well as in DNA isolated from sperm from drug-treated male mice. Further, we demonstrate that first filial generation (F1) offspring from drug-treated male HD transgenic mice show significantly improved HD disease phenotypes compared with F1 offspring from vehicle-treated male HD transgenic mice, in association with increased Kdm5d expression, and decreased histone H3 Lys4 (K4) (H3K4) methylation in the CNS of male offspring. Additionally, we show that overexpression of Kdm5d in mutant HD striatal cells significantly improves metabolic deficits. These findings indicate that HDAC inhibitors can elicit transgenerational effects, via cross-talk between different epigenetic mechanisms, to have an impact on disease phenotypes in a beneficial manner. Bisulphite converted DNA from the 12 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip v1.2. We demonstrate that histone deacetylase (HDAC) inhibition can elicit changes in DNA methylation in Huntington’s disease (HD) human fibroblasts, as well as in sperm from HD transgenic mice, in association with DNA methylation-related gene expression changes. We suggest that alterations in sperm DNA methylation lead to transgenerational effects, and, accordingly, we show that first filial generation (F1) offspring of HDAC inhibitor-treated male HD transgenic mice show improved HD disease phenotypes compared with F1 offspring from vehicle-treated male HD transgenic mice. These findings have significant implications for human health because they enforce the concept that ancestral drug exposure may be a major molecular factor that can affect disease phenotypes, yet in a positive manner. Further, we implicate Lys (K)-specific demethylase 5d expression in this phenomenon.
Project description:This SuperSeries is composed of the following subset Series: GSE22866: DNA Methylation Profiling of Glioblastoma: Impact on Gene Expression and Clinical Outcome (Agilent Expression Study) GSE22867: DNA Methylation Profiling of Glioblastoma: Impact on Gene Expression and Clinical Outcome (Illumina) Refer to individual Series
Project description:DNA methylation and DNA replication timing were examined across a variety of human tissues and cell lines, applying microarray-based techniques. The analyses revealed that late-replicating DNA was demethylated compared to the methylation of early-replicating regions. DNA methylation: Epstein-Barr-Virus (EBV) transformed B-lymphocyte cell lines GM10849, GM12089, GM12092, GM12093, and GM08714 (ICF) (http://ccr.coriell.org/nigms) were cultured in RPMI-1640 supplemented with 15% FCS (Sigma) at 37oC and 5% CO2. Normal BJ foreskin fibroblasts (NHF cells) at different PDs (36)(34) were cultured in 4:1 DMEM : M-199 supplemented with 15% FCS (Sigma) at 37oC and 5% CO2. Replication timing: EBV-transformed female B-lymphocyte cell lines GM12092 and GM12093 were cultured as above, harvested from logarithmic growth cultures, washed once in ice-cold phosphate-buffered saline, immediately fixed in 70-85-95% ethanol at -20oC, stained with propidium iodide, and sorted into G1 and early-S fractions using a MoFlo cell sorter.
Project description:Genome-scale measurements of DNA methylation levels are necessary to decipher the epigenetic events involved in glioblastoma aggressive phenotype, and to guide new therapeutic strategies. In that purpose, we performed a whole genome integrative analysis of the methylation and expression profiles for 40 newly diagnosed glioblastoma patients. We have also screened for associations between CpG sites methylation levels and overall survival in a cohort of 50 patients uniformly treated with radiotherapy and chemotherapy with concomitant and adjuvant temozolomide (STUPP protocol). The methylation analysis identified 616 CpG sites differentially methylated between glioblastoma and control brain, a quarter being differentially expressed in a concordant way. Among these concordant CpG sites, 13 genes displayed, within our glioblastoma cohort, an inverse correlation between promoter methylation and expression levels: B3GNT5, FABP7, ZNF217, BST2, OAS1, SLC13A5, GSTM5, ME1, UBXD3, TSPYL5, FAAH, C7orf13, and C3orf14. The expression of these genes may be tightly regulated by epigenetic mechanisms. The survival analysis identified six CpG sites associated with overall survival. The SOX10 promoter methylation status (two CpG sites) stratifies the patients in a way similar to MGMT with improved performance based on Area Under the Curve criteria (0.78 vs. 0.71, p-value < 5.10-4). The methylation status of FNDC3B, TBX3, DGKI, and FSD1 promoters identify patients with MGMT methylated tumors non-responding to STUPP treatment (p-value < 1.10-4). These markers have a potential impact on therapeutic decision. 55 glioblastoma samples and 3 control brain samples were analysed.
Project description:A low-grade invasive gastro-intestinal stromal tumour (GIST) was subjected to whole-genome sequencing as well as methylation profiling using Illumina 450K BeadChip array, in order to determine the minimal set of genomic and epigenomic alterations necessary to trigger the formation of invasive GIST. single-sample study, DNA extracted from fresh frozen tissue.
Project description:DNA methylation and hydroxymethylation have been implicated in normal development and differentiation, but our knowledge about the genome-wide distribution of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) during cellular differentiation remains limited. Using in vitro model system of gradual differentiation of human embryonic stem (hES) cells into ventral midbrain-type neural precursor (NP) cells and terminally into dopamine (DA) neurons, we explored changes in 5mC or 5hmC patterns during lineage commitment. We used three techniques, 450K DNA methylation array, MBD-seq, and hMeDIP-seq, and found combination of these methods can provide comprehensive information on the genome-wide 5mC or 5hmC patterns. We observed dramatic changes of 5mC patterns during differentiation of hES cells into NP cells. Although genome-wide 5hmC distribution was more stable than 5mC, coding exons, CpG islands and shores showed dynamic 5hmC patterns during differentiation. In addition to the role of DNA methylation as a mechanism to initiating gene silencing, we also found DNA methylation as a locking system to maintain gene silencing. More than 1,000 genes including mesoderm development related genes acquired promoter methylation during neuronal differentiation even though they were already silenced in hES cells. Finally, we found that activated genes lost 5mC in transcription start site (TSS) but acquired 5hmC around TSS and gene body during differentiation. Our findings may provide clues for elucidating the molecular mechanisms underlying lineage specific differentiation of pluripotent stem cells during human embryonic development. Examination of genome-wide DNA methylation in 3 cell types (human embryonic stem, neural precursor, and dopamine neuron cells)
Project description:DNA methylation and hydroxymethylation have been implicated in normal development and differentiation, but our knowledge about the genome-wide distribution of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) during cellular differentiation remains limited. Using in vitro model system of gradual differentiation of human embryonic stem (hES) cells into ventral midbrain-type neural precursor (NP) cells and terminally into dopamine (DA) neurons, we explored changes in 5mC or 5hmC patterns during lineage commitment. We used three techniques, 450K DNA methylation array, MBD-seq, and hMeDIP-seq, and found combination of these methods can provide comprehensive information on the genome-wide 5mC or 5hmC patterns. We observed dramatic changes of 5mC patterns during differentiation of hES cells into NP cells. Although genome-wide 5hmC distribution was more stable than 5mC, coding exons, CpG islands and shores showed dynamic 5hmC patterns during differentiation. In addition to the role of DNA methylation as a mechanism to initiating gene silencing, we also found DNA methylation as a locking system to maintain gene silencing. More than 1,000 genes including mesoderm development related genes acquired promoter methylation during neuronal differentiation even though they were already silenced in hES cells. Finally, we found that activated genes lost 5mC in transcription start site (TSS) but acquired 5hmC around TSS and gene body during differentiation. Our findings may provide clues for elucidating the molecular mechanisms underlying lineage specific differentiation of pluripotent stem cells during human embryonic development. Examination of hMeDIP-Seq and MBD-Seq in 3 cell types (human embryonic stem, neural precursor, and dopamine neuron cells)
Project description:Study of influence of gender and Lead(Pb) exposure on DNA methylation for whole blood measured in dried blood spots for a Detroit cohort of child between the age of 3 months to 5years DNA methylation profiling of dried blood spots for a Detroit cohort of child between the ages of 3 months to 5 years Differential methylation study