ABSTRACT: H2A.B is a unique histone H2A variant that shares only 40 ~ 50 % sequence identity with canonical H2A. It has only been identified in mammals and has quickly evolved with remarkable sequence diversity among different species. H2A.B is ubiquitously expressed in most cells and tissues. It is mainly deposited in gene body region. The localization of H2A.B is associated with methylated CpG islands in mouse ES cells. H2A.B facilitates transcription elongation to go through methylated CpG islands in the gene bodies. One typical example is that H2A.B regulates transcription elongation at imprinted loci. We found H2A.B enriched in some methylated loci. Using ChIP-seq and MeDIP-seq, we test the correlation of H2A.B and DNA methylation.
Project description:Polycomb repressive complex 1 (PRC1) catalyzes H2A monoubiquitination (uH2A) and regulates pluripotency in embryonic stem cells (ESCs). However the mechanisms controlling PRC1 recruitment and activity are largely unknown. Here we show that Fbxl10 interacts with Ring1B and Nspc1, forming a non-canonical PRC1. We demonstrate that Fbxl10-PRC1 is essential for H2A ubiquitination in mouse ESCs. Genome-wide analyses reveal that Fbxl10 preferentially binds to CpG islands and co-localizes with Ring1B on Polycomb target genes. Notably, Fbxl10 depletion causes modest dissociation of Ring1B but a major loss of uH2A on target genes. Furthermore rescue experiments for Fbxl10 reveal that its DNA binding capability and integration into PRC1 are required for proper H2A ubiquitination. ES cells lacking Fbxl10, like previously characterized Polycomb mutants, show a severely compromised capacity for successful differentiation. Our results shed light on a novel mechanism how CpG islands regulate chromatin function by affecting polycomb recruitment and activity. All ChIP-seq reactions were performed in either untransfected cells, cells expressing scrambled shRNA or Fbxl10 shRNA, Ring1b-/- or Suz12-/- mouse ES cells
Project description:The actions of environmental toxicants and relevant mixtures in promoting the epigenetic transgenerational inheritance of ovarian disease was investigated with the use of a fungicide, a pesticide mixture, a plastic mixture, dioxin and a hydrocarbon mixture. After transient exposure of an F0 gestating female rat during embryonic gonadal sex determination, the F1 and F3 generation progeny adult onset ovarian disease was assessed. Transgenerational disease phenotypes observed included an increase in cysts resembling human polycystic ovarian disease (PCO) and a decrease in the ovarian primordial follicle pool size resembling primary ovarian insufficiency (POI). The F3 generation granulosa cells were isolated and found to have a transgenerational effect on the transcriptome and epigenome (differential DNA methylation). Epigenetic biomarkers for environmental exposure and associated gene networks were identified. Epigenetic transgenerational inheritance of ovarian disease states was induced by all the different classes of environmental compounds, suggesting a role of environmental epigenetics in ovarian disease etiology. Granulosa cells from large antral follicles were collected and evaluated from F3 generation rats that were ancestrally exposed to one of the five different treatments: Vinclozolin, Pesticide (includes permethrin and DEET), Plastics (includes BPA, DBP and DEHP), Low-dose Plastics (50% of Plastics dose), Dioxin, Hydrocarbon (Jet fuel JP8), or DMSO vehicle as Control. Vinclozolin lineage alterations in differentially DNA methylated regions (DMR) in the granulosa cells was investigated by using a methylated DNA immunoprecipitation (MeDIP) procedure followed by comparative hybridization on a genome wide promoter tiling array (Chip), termed an MeDIP-Chip assay. The DNA fractions from four animals of the same treatment group were pooled to create three different pooled DNA samples from each of the two treatment groups (experimental vs. control). These DNA samples were then used for methylated DNA immunoprecipitation (MeDIP) using Nimblegen microarrays. Each MeDIP sample was then used to preform three different comparative (amplified MeDIP vs. amplified MeDIP) hybridization experiments (3 sub-arrays), each encompassing DNA samples from 24 animls (3 treatment and 3 control groups).
Project description:Genomewide DNA methylation profiles, generated by MeDIP-seq, for 8.5dpc wildtype and Dnmt3l-/+ mouse embryos were compared to identify differentially methylated regions (DMRs) that depend on the activity of the de novo DNA methyltransferase cofactor Dnmt3l in the oocyte. These DMRs were further characterised by their methylation state in mature mouse sperm and in the livers of inter-subspecies newborn mice. Maternal ICRs were identified by hypomethylation in Dnmt3l-/+ embryos as well as sperm, and maternal allele-specific methylation in liver. MeDIP-seq for two pools of wildtype and two pools of Dnmt3l-/+ mouse 8.5dpc embryos, the sperm of three sires, and 12 pools of three different embryonic livers each. Sliding window read count comparison between wildtype and Dnmt3l-/+ embryos, and between wildtype embryos and sperm samples. Read count comparison between the parental alleles at known SNP sites in inter-subspecies liver data.
Project description:Environmental compounds including fungicides, plastics, pesticides, dioxin and hydrocarbons can promote the epigenetic transgenerational inheritance of adult-onset disease in future generation progeny following ancestral exposure during the critical period of fetal gonadal sex determination. This study examined the actions of the pesticide methoxychlor to promote the epigenetic transgenerational inheritance of adult-onset disease and associated differential DNA methylation regions (i.e. epimutations) in sperm. Gestating F0 generation female rats were transiently exposed to methoxychlor during fetal gonadal development (gestation days 8 to 14) and then adult-onset disease was evaluated in adult F1 and F3 (great-grand offspring) generation progeny for control (vehicle exposed) and methoxychlor lineage offspring. There were increases in the incidence of kidney disease, ovary disease, and obesity in the methoxychlor lineage animals. In females and males the incidence of disease increased in both the F1 and the F3 generations and the incidence of multiple disease increased in the F3 generation. There was increased disease incidence in F4 generation reverse outcross (female) offspring indicating disease transmission was primarily transmitted through the female germline. Analysis of the F3 generation sperm epigenome of the methoxychlor lineage males identified differentially DNA methylated regions (DMR) termed epimutations in a genome-wide gene promoters analysis. These epimutations were found to be methoxychlor exposure specific in comparison with other exposure specific sperm epimutation signatures. Observations indicate that the pesticide methoxychlor has the potential to promote the epigenetic transgenerational inheritance of disease and the sperm epimutations appear to provide exposure specific epigenetic biomarkers for transgenerational disease and ancestral environmental exposures. Methylated sperm DNA was isolated from rats ancestrally exposed to methoxychlor. Three independent samples from each treatment group were obtained. Differential DNA methylation between treatment groups was determined using Nimblegen microarrays. Treated samples were paired with control samples and hybridized together on arrays, resulting in three arrays for the treatment.
Project description:In response to acute infection CD8 T cells differentiate into effector cells capable of clearing the antigen. While the transcriptional and functional changes have previously been studied little is known of the epigenetic modifications that accompany this differentiation process. To gain insights into CD8 T cell effector differentiation and the role of epigenetics, we mapped DNA methylation by MeDIP-seq in naive CD8 T cells and day 8 effector CD8 T cells that are induced following an acute infection. We identified hundreds of thousands of differentially methylated regions (DMRs). Promoter DNA methylation inversely correlated with gene expression and DMRs were enriched for functional transcription factor binding sites. These data indicated that DNA methylation is dynamic during CD8 T cell differentiation and provide a map of possible regulatory regions important in this process. Examination of DNA methylation during CD8 T cell differentiation from naïve to day 8 effectors following acute infection
Project description:To examine whether Dnmt3a deficiency resulted in genomic methylation changes we performed an unbiased methylome analysis. Methylated DNA isolated from three Dnmt3a deficient and two WT tumors was immunoprecipitated and subjected to high throughput sequencing (MeDIP-Seq). We observed that genes that were less expressed in Dnmt3a deficient tumors tended to have lower methylation levels in gene bodies. Examination of methylcytosine in two tumor types
Project description:Arsenic is methylated during its metabolism, thereby depleting the intracellular methyl donor S-adenosyl-methionine, which may lead to disturbances in DNA methylation patterns Cells were exposed to sodium arsenite (NaAsO2, Sigma) at concentrations of 0.08 M-BM-5M, 0.4 M-BM-5M and 2 M-BM-5M for 1, 2 and 8 weeks. A549 arsenic dose time response study.
Project description:Accelerated brain development is a unique feature of the human species. Not only the size but also morphology, in particular the connections between frontal cortex and basal ganglia distinguish the human brain from great apes and other primates. Recent findings suggest that structural features which may be important for language acquisition are influenced by FOXP2, key regulator of CNTNAP2. CNTNAP2 is one of the largest genes in the human genome, encompassing 2.3 Mb. It encodes a neurexin with essential roles in the vertebrate nervous system. The aim of our study was to compare the methylation patterns of CNTNAP2 in human and chimpanzee brains, assuming that epigenetic regulation is essential for brain development and human language abilities. To this end, we designed a NimbleGen tiling array covering the entire human CNTNAP2 gene plus 0.1 Mb up- and downstream flanking sequence with an average resolution of 13 bp. Methylated DNA ImmunoPreciptation (MeDIP) was used to enrich cytosine-methylated DNA fragments for downstream analysis with high-resolution tiling arrays. MeDIP-based CNTNAP2 methylation profiling
Project description:Accelerated brain development is a unique feature of the human species. Not only the size but also morphology, in particular the connections between frontal cortex and basal ganglia distinguish the human brain from great apes and other primates. Recent findings suggest that structural features which may be important for language acquisition are influenced by FOXP2, key regulator of CNTNAP2. CNTNAP2 is one of the largest genes in the chimpanzee genome, encompassing 2.5 Mb. It encodes a neurexin with essential roles in the vertebrate nervous system. The aim of our study was to compare the methylation patterns of CNTNAP2 in human and chimpanzee brains, assuming that epigenetic regulation is essential for brain development and human language abilities. To this end, we designed a NimbleGen tiling array covering the entire chimpanzee CNTNAP2 gene plus 0.1 Mb up- and downstream flanking sequence with an average resolution of 13 bp. Methylated DNA ImmunoPreciptation (MeDIP) was used to enrich cytosine-methylated DNA fragments for downstream analysis with high-resolution tiling arrays. MeDIP-based CNTNAP2 methylation profiling