Project description:Characteristic features of chromatin states are not limited to particular epigenetic modifications but include other regulatory cues, such as linker DNA length, typically ranging from around 35-55 bp in most eu- and heterochromatin domains (Valouev et al, 2011; Voong et al., 2016, Cell) to over 200 bp in nucleosome-depleted regions (NDRs) found at active enhancers and promoters (Schones et al, 2008; Hansen He et al, 2010). To investigate whether and how the nucleosome linker DNA affects chromatin recognition by nuclear proteins we performed a set of affinity purifications using di-nucleosomes incorporating different DNA linkers. Here, we investigated the effect of a 200 bp di-nucleosome linker DNA represented by scrambled DNA or SV40 promoter DNA sequence on the nuclear protein binding to di-nucleosome decorated with promoter-associated modifications, including H3K4me3K9acK14acK18acK23acK27ac, H4K5acK8acK12acK16acK20me2 and histone variant H2A.Z Below is a description (modifications and linker) of di-nucleosomes used in pull-downs with HeLa nuclear extracts followed by label-free MS: 1. H3K4me3-5ac,H4K20me2-4ac, H2AZ, 50bp linker 2. H3K4me3-5ac,H4K20me2-4ac, H2AZ, 200bp scrambled DNA linker 3. H3K4me3-5ac,H4K20me2-4ac, H2AZ, 200bp SV40 promoter DNA linker 4. Unmod. H3&H4, 50bp linker 5. Unmod. H3&H4, 200bp scrambled DNA linker 6. Unmod. H3&H4, 200bp SV40 promoter DNA linker
2023-12-10 | PXD041835 | Pride
Project description:A 173-bp indel in the promoter region of the chicken GSTA2 gene.
Project description:Purpose: Exploring the alteration in CREB/CRTC binding related to long-term memory Methods: The nuclei of Drosophila mushroom bodies were purified and the histone acetylation and CREB/CRTC binding were examined by ChIP-seq using specific antibodies. The sequencing was performed using Miseq, and aligned to dm3 using CLCbio. The sequence reads that passed quality filters were analyzed by peak calling using PICS and ERD equipped on Strand NGS software. This method using two algorisms excludes false-positive calling of peaks. The PICS and ERD were run using a default setting except for the following parameters; for PICS, 120 bp as an average fragment length, 10 bp as a minimum distance between forward and reverse reads, 200 bp as a minimum distance between forward and reverse reads, 100 bp as a window width, with 5% false discovery rate; for ERD, 1.5 as an enrichment factor, 100 bp as a window size, 10 bp as a window slide size, 100 bp as a minimum region size. The peaks obtained by ERD analysis were filtered by an enrichment factor of 2, and a density of reads at 0.12 for CREB and 0.2 for CRTC. The CREB and the CRTC binding sites were determined as the peak-called region in at least 2 samples out of the three replicates. The CREB and the CRTC binding sites located 200 bp vicinity to each other were defined as the CREB/CRTC binding sites. In parallel, the read counts were obtained in the 1 kb window covering entire genome and analyzed by DESeq2, to determine the region enriched with CREB/CRTC in a specific group of samples. The region with increased or decreased CREB/CRTC binding were determined if the region were defined by the CREB/CRTC binding sites in the above criteria. Results: Using an optimized data analysis workflow, the filtered reads amounted to 8-11million reads for CREB in each of 3 replicates, 8-17 million reads for CRTC in each of 3 replicates, and 4.4 million reads for input. Using anti-CREB antibody, we found 239 significant increases in CREB binding out of 4995 CREB/CRTC binding sites 1 day after training. Using anti-CRTC antibody, we found 4989 significant increases in CRTC binding out of 4995 CREB/CRTC binding sites 1 day after spaced training. Conclusions: Our study shows that, although CREB binding is mostly unchanged, CRTC binding is significantly increased after long-term memory formation in Drosophila mushroom bodies.
Project description:To investigate alterations in the DNA methylation of CD4+ T cells in IgA nephropathy (IgAN), we performed an initial whole-genome DNA methylation screening on CD4+ T cells isolated from 6 IgAN patients and 6 healthy subjects (HS). We analyzed more than 485000 CpGs targeted across their promoters, 5'-untranslated regions (UTRs), first exons, gene bodies and 3'UTRs. Some of the most significant differentially methylated regions included genes specifically expressed in T cells and involved in the T cell receptor signaling. In particular, we found hypomethylation in the promoter region of DUSP3 and in the 3’UTR of TRIM27 (chr17:41840001-41845000; ∆β= -0.39; chr6:28876508-28893266; ∆β= -0.31). The products of these genes function as signal transductors of the T cell receptor. Moreover, in the chromosome 5 (chr5:135416205-135416475) we found the most strongly and extensively hypermethylated region in IgAN patients respect to HS (∆β=0.31) in the promoter region of VTRNA2-1 gene (known as precursor microRNA miR-886). The methylated region, 200 bp upstream of the transcription start site, it is also part of a CpG island.
Project description:Eukaryotic chromosomes are composed of chromatin, in which regularly spaced nucleosomes containing ~147 bp of DNA are separated by linker DNA. Most eukaryotic cells have a characteristic average nucleosome spacing of ~190 bp, corresponding to a ~45 bp linker. However, cortical neurons have a shorter average spacing of ~165 bp. The significance of this atypical global chromatin organization is unclear. We have compared the chromatin structures of purified mouse dorsal root ganglia (DRG) neurons, cortical oligodendrocyte precursor cells (OPCs) and cortical astrocytes. DRG neurons have short average spacing (~165 bp), whereas OPCs (~182 bp) and astrocytes (~183 bp) have longer spacing. We measured nucleosome positions by MNase-seq and gene expression by RNA-seq. Most genes in all three cell types have a promoter chromatin organization typical of active genes: a nucleosome-depleted region at the promoter flanked by regularly spaced nucleosomes phased relative to the transcription start site. In DRG neurons, the spacing of phased nucleosomes downstream of promoters (~178 bp) is longer than expected from the genomic average, whereas phased nucleosome spacing in OPCs and astrocytes is similar to the global average (~183 bp). Thus, the atypical nucleosome spacing of neuronal chromatin does not extend to promoter-proximal regions.
Project description:A) Chromatins were prepared from Cdx2-inducible ES cells cultured for 48 - 60 hours in the Dox+ and Dox- conditions. Chromatin immunoprecipitation (ChIP) was carried out by using anti-FLAG M2 affinity gel. ChIP product was tested by Western blotting using anti-FLAG antibody. Nuclear extract from ES cells cultured for 48 - 60 hours in Dox+ and Dox- condition was used for the Western blot. B) CDX2 ChIP-Seq peaks in the Hoxa7 gene region. UCSC Mouse Mm9 browser view of Hoxa7 gene locus after mapping CDX2 ChIP-Seq tags locations in the wiggle format. CDX2 ChIP-Seq peaks are shown in red color. C) Cdx2 ChIP-Seq result was verified by qPCR. Target genes were indicated in (G). Primers flanking a promoter region of Hbb-b1 and Pou5f1 as well as a gene desert region in chromosome 3 were used as negative controls. Primers flanking of Actb gene promoter were used for normalization. The relative enrichment of CDX2 binding was indicated as fold change. (D) CDX2-binding motifs identified with CisFinder using 200 bp sequences centered at ChIP sites. (F) Potential CDX2-direct target genes based on ChIP-Seq and the alteration of expression by Cdx2-overexpression. (G) Identification of CDX2 target genes by combining information on binding sites with gene expression response to Cdx2 over-expression
Project description:A) Chromatins were prepared from Cdx2-inducible ES cells cultured for 48 - 60 hours in the Dox+ and Dox- conditions. Chromatin immunoprecipitation (ChIP) was carried out by using anti-FLAG M2 affinity gel. ChIP product was tested by Western blotting using anti-FLAG antibody. Nuclear extract from ES cells cultured for 48 - 60 hours in Dox+ and Dox- condition was used for the Western blot. B) CDX2 ChIP-Seq peaks in the Hoxa7 gene region. UCSC Mouse Mm9 browser view of Hoxa7 gene locus after mapping CDX2 ChIP-Seq tags locations in the wiggle format. CDX2 ChIP-Seq peaks are shown in red color. C) Cdx2 ChIP-Seq result was verified by qPCR. Target genes were indicated in (G). Primers flanking a promoter region of Hbb-b1 and Pou5f1 as well as a gene desert region in chromosome 3 were used as negative controls. Primers flanking of Actb gene promoter were used for normalization. The relative enrichment of CDX2 binding was indicated as fold change. (D) CDX2-binding motifs identified with CisFinder using 200 bp sequences centered at ChIP sites. (F) Potential CDX2-direct target genes based on ChIP-Seq and the alteration of expression by Cdx2-overexpression. (G) Identification of CDX2 target genes by combining information on binding sites with gene expression response to Cdx2 over-expression Chromatin IP against CDX2-Flag fusion protein. MC1 ES cells were genetically modified for ROSA26 locus to have Tet-Off expression cassette for C-terminal FLAG tagged Cdx2. The peaks are obtained from the Eland Multi Alignment file. The number of tags in peaks was compared with the number of tags in the control sample for the same region corrected by the total coverage of tags. See supplemental file of the paper for details.
Project description:To investigate alterations in the DNA methylation of CD4+ T cells in IgA nephropathy (IgAN), we performed an initial whole-genome DNA methylation screening on CD4+ T cells isolated from 6 IgAN patients and 6 healthy subjects (HS). We analyzed more than 485000 CpGs targeted across their promoters, 5'-untranslated regions (UTRs), first exons, gene bodies and 3'UTRs. Some of the most significant differentially methylated regions included genes specifically expressed in T cells and involved in the T cell receptor signaling. In particular, we found hypomethylation in the promoter region of DUSP3 and in the 3âUTR of TRIM27 (chr17:41840001-41845000; âβ= -0.39; chr6:28876508-28893266; âβ= -0.31). The products of these genes function as signal transductors of the T cell receptor. Moreover, in the chromosome 5 (chr5:135416205-135416475) we found the most strongly and extensively hypermethylated region in IgAN patients respect to HS (âβ=0.31) in the promoter region of VTRNA2-1 gene (known as precursor microRNA miR-886). The methylated region, 200 bp upstream of the transcription start site, it is also part of a CpG island. Bisulfite-converted DNA from the 12 samples (CD4+ T cells from 6 IgAN patients and 6 healthy subjects) were hybridised to the Illumina Infinium HumanMethylation450 BeadChip.
Project description:ChIP seq of Cfp-1 and H3K4me3 in C. elegans late embryos The coding region of F52B11.1a (cfp-1) was PCR amplified from N2 genomic DNA using Phusion polymerase (Finnzymes) and Gateway cloned into pDONR221. The cfp-1 coding region was then recombined into the MosSCI compatible vector pCFJ201 (which targets Mos site Mos1(cxTi10882) chrIV ) downstream of the dpy-30 promoter and upstream of gfp::tbb-2 3’UTR (Zeiser et al. 2011) to generae strain JA1597 expressing GFP tagged Cfp-1 protein. Late embryos were obtained by aging embryos collected by hypochlorite treatment 3.5 hrs prior to flash freezing in liquid nitrogen. Formaldehyde-fixed chromatin extracts and chromatin immunoprecipitations were as in (Kolasinska-Zwierz et al. 2009) except that DNA was sonicated to a size range of 200-400bp. ChIP assays were performed in 1 ml extract (1 mg protein) in FA buffer with 10 micrograms of anti-GFP rabbit serum (Abcam ab290) and anti-H3K4me3 (Abcam ab8580) individually. DNA sequencing libraries were constructed according using the Illumina Truseq sequencing kit and were sequenced on the Illumina platform.