Low input Hi-C datasets for a diffuse large B-cell lymphoma sample, healthy control human B-cells and mouse embryonic stem cells
ABSTRACT: In this experiment, we've examined chromatin conformation of OG2 (B6; CBA-Tg(Pou5f1-EGFP)2Mnn/J; stock number 004654) mouse stem cells cultured as described in (Shi et al., 2008), using different amounts of starting cells. We performed a modified in situ Hi-C protocol for 6 samples digested with MboI restriction enzyme having as starting material 1 million (M), 100 thousand (k), 50k, 25k, 10k or 1k cells. As well as, to 2 samples digested with HindIII restriction enzyme that had as starting material 5M or 100k cells. Traditional in situ Hi-C protocols recommend 5-10 million starting cells. The aim of the experiment was to assess the impact of decreasing the cell number on reproducibility, library complexity, chromatin structure visualization in order to adapt the method to the study of rare cell populations. Furthermore, we have characterised the 3D structure of peripheral blood mononuclear cells (PBMCs) obtained from a blood extraction from a healthy donor and from a lymph node biopsy from a DLBCL patient as a proof of concept for the suitability of Low-C for rare cell population analysis.
Project description:In this experiment, we've examined chromatin conformation differences of E14 mESC against cohesin and Ring1b degrons. We performed a modified in situ Hi-C protocol from (Rao et al., 2014) that can be found in detail at (Díaz et al., 2018). Samples were digested with MboI restriction enzyme. The aim of the experiment was to characterize the role of cohesin and polycomb on the 3D structure of mouse chromatin.
Project description:Hi-C was carried out for control embryos and embryos produced from gd7, Tollrm9/rm10, and Toll10B mutant mothers. The embryos from mutant mothers produce only a single type along the dorsal-ventral axis. We used these embryos to compare chromatin conformation across tissues.
Project description:2×10^7 HL60 cells were treated with 10 uM ATRA for 2 and 5 days, and conducted Hi-C to study the chromosomal architecture. Cells were fixed by 1% formaldehyde (v/v) for 15 min at room temperature (RT) with slowly rotation. Cells were lysed by 550 μl lysis buffer (500 μl 10 mM Tris-HCl pH 8.0, 10 mM NaCl, 0.2% Igepal CA-630 and 50 μl protease inhibitors) using a homogenizer, and harvested the chromatin at 5,000 rpm and washed twice. The pellet was added 1% SDS and incubated at 65 oC for 10 min, then quenched by Triton X-100. The chromatin was digested by 600 U MboI (NEB, Ipswich, USA) at 37 oC overnight. The next day, enzymes were inactivated by 10% SDS at 65 oC for 30 min, and the restriction fragment overhangs were filled in using biotin-14-dCTP and Klenow at 37 oC for 45 min, and the ligation was conducted in 7.61 ml ligation mix (745 μl 10% Triton X-100, 745 μl 10x ligation buffer (500 mM Tris-HCl pH 7.5, 100 mM MgCl2, 100 mM DTT), 80 μl 10 mg/ml BSA, 80 μl 100 mM ATP and 5.96 ml water) for 4 h at 16°C. The blunt-end Hi-C ligation was sonicated and pull down by streptavidin beads, then purified by ethanol. Hi-C library was prepared for paired ending sequencing using NEBNext® UltraTM DNA Library Prep Kit for Illuina® (NEB). For regular 3C ligation, after enzymes inactivation, 10 μl 1 U/μl T4 DNA ligase was added to incubate at 16°C overnight. The interaction was detected by qPCR using the specific 3C primers (Table 1) followed by DNA purification. Hi-C was conducted in PE-150. An iterative method for Hi-C mapping with initial length 30bp, if it fails to map uniquely, the next round of mapping for additional 20 bp continued, this procedure lasts until the full read length reaches 150bp. The Hi-C reads were mapped to the human reference genome (assembly GRCh38) using bowtie2 (v2.2.9). The reads mapped to the same restriction fragment, the reads less than 500bp and PCR duplicates were all removed. Hi-C contact maps were normalized using ICE.
Project description:The relationship between chromatin organization and transcriptional regulation is an area of intense investigation. We have characterized the spatial relationships between alleles of the Oct4, Sox2, and Nanog genes in single cells during the earliest stages of mouse embryonic stem cell (ESC) differentiation and during embryonic development. We describe homologous pairing of the Oct4 alleles during ESC differentiation and embryogenesis, and present evidence that pairing is correlated with the kinetics of ESC differentiation. Importantly, we identify critical DNA elements within the Oct4 promoter/enhancer region that mediate pairing of Oct4 alleles. Finally, we show that mutation of OCT4/SOX2 binding sites within this region abolishes inter-chromosomal interactions and affects accumulation of the repressive H3K9me2 modification at the Oct4 enhancer. Our findings demonstrate that chromatin organization and transcriptional programs are intimately connected in ESCs, and that the dynamic positioning of the Oct4 alleles is associated with the transition from pluripotency to lineage specification. Examination of chromatin contacts between Oct4 alleles using PE-4Cseq
Project description:The CrdR-ChIP profiling is comparing H. pylori gDNA without crdR interaction as control and CrdR interact with H. pylori gDNA (WT vs crdR). The goal was determine the crdR binding site on H. pylori genome, it provide possible crdR-regulated genes. 2 samples: H. pylori 26695 is control, and CrdR is experiment.
Project description:The experiment was carried out to examine the effect of Srrt knockdown on the U1 snRNP/pre-mRNA interaction pattern. A2Lox mouse embryonic stem cells were transfected with either an Srrt-specific or a non-targeting siRNA. 48 hours post transfection the cells were cross-linked using 2% formaldehyde and lysed. RNA was partially fragmented by sonication, hybridized with U1 snRNA-specific biotinilated probes and pulled down. U1-associated RNA sequences were then purified and RNA-seq libraries were generated using a NEBNext® rRNA Depletion Kit and NEBNext® Ultra8482 II Directional RNA Library Preparation kit. Paired-end sequencing was performed using a HiSeq4000 75bp platform.
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:In bacteria, translation-transcription coupling inhibits RNA polymerase (RNAP) stalling. We present evidence suggesting that, upon amino acid starvation, inactive ribosomes promote rather than inhibit RNAP stalling. We developed an algorithm to evaluate genome-wide polymerase progression independently of local noise, and used it to reveal that the transcription factor DksA inhibits promoter-proximal pausing and increases RNAP elongation when uncoupled from translation by depletion of charged tRNAs. DksA has minimal effect on RNAP elongation in vitro and on untranslated RNAs in vivo. In these cases, transcripts can form RNA structures that prevent backtracking. Thus, the effect of DksA on transcript elongation may occur primarily upon ribosome slowing/stalling or at promoter-proximal locations that limit the potential for RNA structure. We propose that inactive ribosomes prevent formation of backtrackblocking mRNA structures and that, in this circumstance, DksA acts as a transcription elongation factor in vivo. Chromatin immunoprecipitation (ChIP) experiments were performed by using antibodies against RNA polymerase b subunit in wild-type and DdksA cells treated with 0.5mg/ml serine hydroxamate (SHX) or untreated. DksA and s70 enrichments were compared to RNAP enrichment by ChIP experiments using antibodies against s70 and DksA in wild-type cells (also in DdksA cells as a negative control for DksA ChIP-chip). Differentially labeled ChIP DNA and genomic DNA were competitively hybridized to an E. coli K-12 MG1655 tiling array with overlapping probes at ~12bp spacing across the entire genome. The series contains 19 datasets.