Project description:DNA methylation is critical for normal development and plays important roles in genome organization and transcriptional regulation. Although DNA methyltransferases have been identified, the factors that establish and contribute to genome-wide methylation patterns remain elusive. Here, we report a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences. We provide evidence that Lsh also controls genome-wide cytosine methylation at nonrepeat sequences and relate those changes to alterations in H4K4me3 modification and gene expression. Deletion of Lsh alters the allocation of cytosine methylation in chromosomal regions of 50 kb to 2 Mb and, in addition, leads to changes in the methylation profile at the 5′ end of genes. Furthermore, we demonstrate that loss of Lsh promotes—as well as prevents—cytosine methylation. Our data indicate that Lsh is an epigenetic modulator that is critical for normal distribution of cytosine methylation throughout the murine genome. We used microarrays to detail a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences To investigate how genome-wide DNA methylation patterns are established in mice and how they may specifically depend on Lsh, we generated a comprehensive genomic map of cytosine methylation for wild-type (WT) and Lsh−/− mouse embryonic fibroblasts (MEFs) using methylated DNA immunoprecipitation (MeDIP) combined with whole-genome tiling microarray. In addition, we generated a histone 3 lysine 4 trimethylation (H3K4me3) chromatin map using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-Seq) and also evaluated genome-wide gene expression using cDNA microarrays
Project description:Whole-genome single-base resolution methylcytosine map reveals profound changes that occur after Lsh deletion during embryonic development in primary WT and Lsh-/- MEFs. Lsh deletion leads to widespread decreases of CG methylation level at uniquely mapped genomic regions compared to wild type, including TSSs at protein-coding genes, and non-coding RNA genes. MethylC-Seq from Mus musculus primary MEFs.
Project description:DNA methylation is critical for normal development and plays important roles in genome organization and transcriptional regulation. Although DNA methyltransferases have been identified, the factors that establish and contribute to genome-wide methylation patterns remain elusive. Here, we report a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences. We provide evidence that Lsh also controls genome-wide cytosine methylation at nonrepeat sequences and relate those changes to alterations in H4K4me3 modification and gene expression. Deletion of Lsh alters the allocation of cytosine methylation in chromosomal regions of 50 kb to 2 Mb and, in addition, leads to changes in the methylation profile at the 5M-CM-"M-BM-^@M-BM-2 end of genes. Furthermore, we demonstrate that loss of Lsh promotesM-CM-"M-BM-^@M-BM-^Tas well as preventsM-CM-"M-BM-^@M-BM-^Tcytosine methylation. Our data indicate that Lsh is an epigenetic modulator that is critical for normal distribution of cytosine methylation throughout the murine genome. Chromatin immunoprecipitation followed by genomic sequencing was used to compare H3K4me3 modifications between wild type murine embryonal fibroblast cell lines (MEFs) and Lsh-/-MEFs.
Project description:Background: Global DNA methylation contributes to genomic integrity by supressing repeat associated transposition events. Several chromatin factors are required in addition to DNA methyltransferases to maintain DNA methylation at intergenic and satellite repeats. Embryos lacking Lsh, a member of the SNF2 superfamily of chromatin helicases, are hypomethylated. The interaction of Lsh with the de novo methyltransferase, Dnmt3b, facilitates the deposition of DNA methylation at stem cell genes. We wished to determine if a similar targeting mechanism operates to maintain DNA methylation at repetitive sequences. Results: We used HELP-seq to map genome wide DNA methylation patterns in Lsh-/- and Dnmt3b-/- somatic cells. DNA methylation is predominantly lost from specific genomic repeats in Lsh-/- cells: LTR-retrotransposons, LINE-1 repeats and mouse satellites. RNA-seq experiments demonstrate that specific IAP (Intracisternal A-type particle) LTRs and satellites, but not LINE-1 elements, are aberrantly transcribed inLsh-/- cells. LTR hypomethylation in Dnmt3b-/- cells is moderate and hypomethylated repetitive elements (IAP, LINE-1 and satellite) are silent. Chromatin immunoprecipitation (ChIP) indicates that repressed LINE-1 elements gain H3K4me3, but H3K9me3 levels are unaltered in Lsh-/- cells, indicating that DNA hypomethylation alone is not permissive for their transcriptional activation. Mis-expressed IAPs and satellites lose H3K9me3 and gain H3K4me3 in Lsh-/- cells. Conclusions: Our study emphasizes that regulation of repetitive elements by DNA methylation is selective and context dependent. We propose a model where Lsh is specifically required at a precise developmental window to target de novo methylation to repeat sequences, which is subsequently maintained by Dnmt1 in somatic cells to enforce repeat silencing thus contributing to genomic integrity. Two pairs of genomic samples compared: WT and Lsh-/- DNA isolations from tail-tip fibroblasts; WT and Dnmt3b knockout DNA isolations from mouse embryonic fibroblasts.
Project description:Purpose: We aimed to determine whether the expression of either wild-type or catalytically inactive LSH, carrying a single point mutation in its ATP binding site (K237Q), could restore the levels and patterns of DNA methylation in Lsh-/- mouse embryonic fibroblasts (MEFs). Methods: Lsh-/- MEFs were transduced with lentiviral particles carrying empty pMSCV vector, pMSCV-LSH-3xFLAG and pMSCV-LSH K/Q-3xFLAG, respectively. Clonal cell lines were generated and tested for LSH expression. Two independent cell lines expressing wild-type LSH and two expressing LSH K/Q were used for further analyses and comparison with wild-type MEFs and Lsh-/- MEFs carrying the empty vector. Genomic DNA was purified from all six cell lines and methylated DNA immunoprecipitation (MeDIP) was performed as described in Weber et al., 2007, Nat Genetics. MeDIP libraries were generated and sequenced on Illumina HiSeq 2000 instrument. Results and conclusions: Our experiments demonstrate that the expression of wild-type LSH, but not the catalytically inactive LSH K/Q, in Lsh-/- MEFs leads to reestablishment of DNA methylation at repetitive sequences and unique developmentally regulated loci in a cell-autonomous manner. Analyses of DNA methylation upon expression of either wild-type or catalytically-inactive LSH in Lsh-/- mouse embryonic fibroblasts.
Project description:MBD-affinity purification (MAP) was employed to investigate the DNA methylation status at promoters of mouse embryonic fibroblasts (MEFs), both wild type and Lsh knock-out cells.<br>MAP is conceptually identical to ChIP, using an affinity column rather than an antibody.
Project description:DNA methylation is critical for normal development and plays important roles in genome organization and transcriptional regulation. Although DNA methyltransferases have been identified, the factors that establish and contribute to genome-wide methylation patterns remain elusive. Here, we report a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences. We provide evidence that Lsh also controls genome-wide cytosine methylation at nonrepeat sequences and relate those changes to alterations in H4K4me3 modification and gene expression. Deletion of Lsh alters the allocation of cytosine methylation in chromosomal regions of 50 kb to 2 Mb and, in addition, leads to changes in the methylation profile at the 5′ end of genes. Furthermore, we demonstrate that loss of Lsh promotes—as well as prevents—cytosine methylation. Our data indicate that Lsh is an epigenetic modulator that is critical for normal distribution of cytosine methylation throughout the murine genome. We used microarrays to detail a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences
Project description:DNA methylation is critical for normal development and plays important roles in genome organization and transcriptional regulation. Although DNA methyltransferases have been identified, the factors that establish and contribute to genome-wide methylation patterns remain elusive. Here, we report a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences. We provide evidence that Lsh also controls genome-wide cytosine methylation at nonrepeat sequences and relate those changes to alterations in H4K4me3 modification and gene expression. Deletion of Lsh alters the allocation of cytosine methylation in chromosomal regions of 50 kb to 2 Mb and, in addition, leads to changes in the methylation profile at the 5′ end of genes. Furthermore, we demonstrate that loss of Lsh promotes—as well as prevents—cytosine methylation. Our data indicate that Lsh is an epigenetic modulator that is critical for normal distribution of cytosine methylation throughout the murine genome. We used microarrays to detail a correlation between cytosine methylation of murine genome modulated by Lsh at non-repetitive sequence and corresponding gene expression.
Project description:DNA methylation is critical for normal development and plays important roles in genome organization and transcriptional regulation. Although DNA methyltransferases have been identified, the factors that establish and contribute to genome-wide methylation patterns remain elusive. Here, we report a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences. We provide evidence that Lsh also controls genome-wide cytosine methylation at nonrepeat sequences and relate those changes to alterations in H4K4me3 modification and gene expression. Deletion of Lsh alters the allocation of cytosine methylation in chromosomal regions of 50 kb to 2 Mb and, in addition, leads to changes in the methylation profile at the 5â² end of genes. Furthermore, we demonstrate that loss of Lsh promotesâas well as preventsâcytosine methylation. Our data indicate that Lsh is an epigenetic modulator that is critical for normal distribution of cytosine methylation throughout the murine genome.
Project description:DNA methylation is critical for normal development and plays important roles in genome organization and transcriptional regulation. Although DNA methyltransferases have been identified, the factors that establish and contribute to genome-wide methylation patterns remain elusive. Here, we report a high-resolution cytosine methylation map of the murine genome modulated by Lsh, a chromatin remodeling family member that has previously been shown to regulate CpG methylation at repetitive sequences. We provide evidence that Lsh also controls genome-wide cytosine methylation at nonrepeat sequences and relate those changes to alterations in H4K4me3 modification and gene expression. Deletion of Lsh alters the allocation of cytosine methylation in chromosomal regions of 50 kb to 2 Mb and, in addition, leads to changes in the methylation profile at the 5′ end of genes. Furthermore, we demonstrate that loss of Lsh promotes—as well as prevents—cytosine methylation. Our data indicate that Lsh is an epigenetic modulator that is critical for normal distribution of cytosine methylation throughout the murine genome.