Replication Timing by Repli-seq from ENCODE/University of Washington
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE34399 | GEO | 2012/04/27
REPOSITORIES: GEO
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Project description:This track is produced as part of the ENCODE Project. This track shows genome-wide assessment of DNA replication timing in cell lines using the sequencing-based "Repli-seq" methodology (see below). Replication timing is known to be an important feature for epigenetic control of gene expression that usually operates at a higher-order level than at the level of specific genes. For each experiment (cell line, replicate), replication timing was ascertained by the isolation and sequencing of newly replicated DNA from six cell cycle fractions: G1/G1b, S1, S2, S3, S4, G2 (six fraction profile). Replication patterns are visualized as a continuous function based on sequencing tag density (Percentage-normalized Signal) and as a wavelet-smoothed transform of the six fraction profile (Wavelet-smoothed Signal). Replication peaks corresponding to replication initiation zones (Peaks) and valleys corresponding to replication termination zones (Valleys) were determined from local maxima and minima, respectively, in the wavelet-smoothed signal data. A measure of relative copy number at each genomic location (Summed Densities) was determined by summing the normalized tag density values of each cell cycle fraction at that location (equals one replicated genome equivalent). For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Cells were grown according to the approved ENCODE cell culture protocols. Repli-seq was performed as described by Hansen et al. (2010). Briefly, newly replicated DNA was labeled in vivo with a pulse of 5-bromo-2-deoxyuridine (BrdU), cells were fractionated into six different parts of the cell cycle by flow cytometry according to DNA content, cell cycle fractionated DNA was sonicated and an anti-BrdU monoclonal antibody was used to isolate the newly replicating DNA. Fragment ends were sequenced using the Illumina Genome Analyzer II or HiSeq platforms (36 bp reads). Some experiments (BJ, K562, BG02ES, GM06990) were originally performed and mapped to an earlier version of the human reference genome NCBI36/hg18 (Hansen et al., 2010) and were remapped to the more recent reference genome GRCh37/hg19. Uniquely mapping high-quality reads were mapped to the genome minus the Y chromosome. Replication signals within each six cell cycle fraction were derived from the density of sequence tags mapping within a 50 kb sliding window (stepped 1 kb across the genome); these densities were normalized to 4 million tags per genome. To avoid variation due to copy number or sequence bias, cell cycle-specific replication signals at each location were determined as a percentage of the sum of the six normalized tag density signals (Percentage-normalized Signal). To transform the six fraction replication signals into one track (Wavelet-smoothed Signal), the percentage-normalized signals at each location were used to calculate a weighted average value based on the average DNA content of each fraction according to flow cytometry [higher values correspond to earlier replication; formula=(0.917*G1b)+(0.750*S1)+(0.583*S2)+(0.417*S3)+(0.250*S4)+(0*G2)]. These weighted average data were smoothed by wavelet transformation [J7 level, corresponding to a scale of 128 kb; see Thurman et al. (2007)]. Replication initiation zones were flagged by determining local maxima in the wavelet-smoothed data (Peaks) and, similarly, replication termination zones were flagged by local minima (Valleys). The sum of the 4 million normalized replication tag densities correspond to replication of one genome and can, therefore, be used as a measure of relative genomic copy number (Summed Densities). This is useful for evaluation of unusual replication patterns, such as "biphasic" ones where replication has both early and late components [as described by Hansen et al. (2010)].
2012-04-26 | E-GEOD-34399 | biostudies-arrayexpress
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (Richard Sandstrom mailto:sull@u.washington.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track is produced as part of the ENCODE Project. This track shows DNaseI sensitivity measured genome-wide in different cell lines using the Digital DNaseI methodology (see below), and DNaseI hypersensitive sites. DNaseI has long been used to map general chromatin accessibility and DNaseI hypersensitivity is a universal feature of active cis-regulatory sequences. The use of this method has led to the discovery of functional regulatory elements that include enhancers, insulators, promotors, locus control regions and novel elements. For each experiment (cell type) this track shows DNaseI sensitivity as a continuous function using sequencing tag density (Raw Signal), and discrete loci of DNaseI sensitive zones (HotSpots) and hypersensitive sites (Peaks)." For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Cells were grown according to the approved ENCODE cell culture protocols. Digital DNaseI was performed by DNaseI digestion of intact nuclei, isolating DNaseI 'double-hit' fragments as described in Sabo et al. (2006), and direct sequencing of fragment ends (which correspond to in vivo DNaseI cleavage sites) using the Solexa platform (36 bp reads). Uniquely mapping high-quality reads were mapped to the genome. DNaseI sensitivity is directly reflected in raw tag density (Raw Signal), which is shown in the track as density of tags mapping within a 150 bp sliding window (at a 20 bp step across the genome). DNaseI sensitive zones (HotSpots) were identified using the HotSpot algorithm described in Sabo et al. (2004). 1.0% false discovery rate thresholds (FDR 0.01) were computed for each cell type by applying the HotSpot algorithm to an equivalent number of random uniquely mapping 36mers. DNaseI hypersensitive sites (DHSs or Peaks) were identified as signal peaks within FDR 1.0% hypersensitive zones using a peak-finding algorithm.
2011-06-03 | E-GEOD-29692 | biostudies-arrayexpress
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (Richard Sandstrom mailto:sull@u.washington.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track is produced as part of the ENCODE Project. This track shows DNaseI sensitivity measured genome-wide in different cell lines using the Digital DNaseI methodology (see below), and DNaseI hypersensitive sites. DNaseI has long been used to map general chromatin accessibility and DNaseI hypersensitivity is a universal feature of active cis-regulatory sequences. The use of this method has led to the discovery of functional regulatory elements that include enhancers, insulators, promotors, locus control regions and novel elements. For each experiment (cell type) this track shows DNaseI sensitivity as a continuous function using sequencing tag density (Raw Signal), and discrete loci of DNaseI sensitive zones (HotSpots) and hypersensitive sites (Peaks)." For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf
2011-06-03 | GSE29692 | GEO
Project description:DNA replication in mammalian cells occurs in a defined temporal order during S phase, known as the replication timing programme. Replication timing is developmentally regulated and correlated with chromatin conformation and local transcriptional potential. Here we present RT profiles of unprecedented temporal resolution in two human embryonic stem cell lines, human colon carcinoma line HCT116 as well as F1 sub-species hybrid mouse embryonic stem cells and their neural progenitor derivatives. Strong enrichment of nascent DNA in fine temporal windows reveals a remarkable degree of cell to cell conservation in replication timing and patterns of replication genome-wide. We identify 5 patterns of replication in all cell types, consistent with varying degrees of initiation efficiency. Zones of replication initiation were found throughout S phase and resolved to ~50kb precision. Temporal transition regions were resolved into segments of uni-directional replication punctuated with small zones of inefficient initiation. Small and large valleys of convergent replication were consistent with either termination or broadly distributed initiation, respectively. RT correlated with chromatin compartment across all cell types but correlations of initiation time to chromatin domain boundaries and histone marks were cell type specific. Haplotype phasing revealed previously unappreciated regions of allele-specific and allele-independent asynchronous replication. Allele-independent asynchrony was associated with large transcribed genes that resemble common fragile sites. Altogether, these data reveal a remarkably deterministic temporal choreography of DNA replication in mammalian cells.
2019-09-20 | GSE137764 | GEO
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (Richard Sandstrom mailto:sull@u.washington.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track is produced as part of the ENCODE Project. This track displays maps of genome-wide binding of the CTCF transcription factor in different cell lines using ChIP-seq high-throughput sequencing For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Cells were grown according to the approved ENCODE cell culture protocols. Cells were crosslinked with 1% formaldehyde, and the reaction was quenched by the addition of glycine. Fixed cells were rinsed with PBS, lysed in nuclei lysis buffer, and the chromatin was sheared to 200-500 bp fragments using Fisher Dismembrator (model 500). Sheared chromatin fragments were immunoprecipitated with specific polyclonal antibodies at 4 degrees C with gentle rotation. Antibody-chromatin complexes were washed and eluted. The cross linking in immunoprecipitated DNA was reversed and treated with RNase-A. Following proteinase K treatment, the DNA fragments were purified by phenol-chloroform-isoamyl alcohol extraction and ethanol precipitation. 20-50 ng of ChIP DNA was end-repaired, adenine ligated to Illumina adapters was added, and then a Solexa library was made for sequencing. ChIP-seq affinity is directly reflected in raw tag density (Raw Signal), which is shown in the track as density of tags mapping within a 150 bp sliding window (at a 20 bp step across the genome). ChIP-seq affinity zones (HotSpots) were identified using the HotSpot algorithm described in Sabo et al. (2004). 1.0% false discovery rate thresholds (FDR 0.01) were computed for each cell type by applying the HotSpot algorithm to an equivalent number of random uniquely mapping 36mers. ChIP-seq affinity (Peaks) were identified as signal peaks within FDR 1.0% hypersensitive zones using a peak-finding algorithm.
2011-06-29 | E-GEOD-30263 | biostudies-arrayexpress
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (Richard Sandstrom mailto:sull@u.washington.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track was produced as part of the ENCODE Project. This track displays genome-wide maps of histone modifications in different cell lines (http://hgwdev.cse.ucsc.edu/cgi-bin/hgEncodeVocab?type=cellType) using ChIP-seq high-throughput sequencing. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Cells were grown according to the approved ENCODE cell culture protocols (http://hgwdev.cse.ucsc.edu/ENCODE/protocols/cell). Cells were cross-linked with 1% formaldehyde, and the reaction was quenched by the addition of glycine. Fixed cells were rinsed with PBS, lysed in nuclei lysis buffer, and the chromatin was sheared to 200-500 bp fragments using a Fisher Dismembrator (model 500). Sheared chromatin fragments were immunoprecipitated with specific polyclonal antibodies at 4 °C with gentle rotation. Antibody-chromatin complexes were washed and eluted. The cross-linking in the immunoprecipitated DNA was reversed and treated with RNase-A. Following proteinase K treatment, the DNA fragments were purified by phenol-chloroform-isoamyl alcohol extraction and ethanol precipitation. A quantity of 20-50 ng of ChIP DNA was end-repaired, followed by the addition of adenine, ligation to Illumina adapters, and creation of a Solexa library for sequencing. ChIP-seq affinity was directly measured through the raw tag density (Raw Signal), which is shown in the track as density of tags mapping within a 150 bp sliding window (at a 20 bp step across the genome). ChIP-seq affinity zones (HotSpots) were identified using the HotSpot algorithm described in Sabo et al. (2004). One percent false discovery rate thresholds (FDR 1.0%) were computed for each cell type by applying the HotSpot algorithm to an equivalent number of random uniquely mapping 36-mers. ChIP-Seq affinities (Peaks) were identified as signal peaks within FDR 1.0% hypersensitive zones using a peak-finding algorithm. All tracks have a False Discovery Rate of 1% (FDR 1.0%). Data were verified by sequencing biological replicates displaying a correlation coefficient > 0.9.
2012-06-07 | E-GEOD-35583 | biostudies-arrayexpress
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (Philip Cayting mailto:pcayting@stanford.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track shows probable binding sites of the specified transcription factors (TFs) in the given cell types as determined by chromatin immunoprecipitation followed by high throughput sequencing (ChIP-Seq). Included for each cell type is the input signal, which represents the control condition where no antibody targeting was performed. For each experiment (cell type vs. antibody) this track shows a graph of enrichment for TF binding (Signal), along with sites that have the greatest evidence of transcription factor binding (Peaks). For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf
2011-08-30 | GSE31477 | GEO
Project description:In order to address the replication timing of the centromeres in yeast Candida albicans, we have determined at high temporal and spatial resolution its genome-wide DNA replication timing profile. This was done by sorting S- and G1-phase cells by FACS and hybridizing DNA from both fractions onto genomic tiling arrays. Data was normalized, organized by chromosomal positition, and smoothed. Replication timing is inferred from the DNA copy number along the chromosome with data peaks corresponding to predicted origins of DNA replication. We observe that the centromeric loci coincide with replication origins that are the first to replicate on each chromosome. We further analyzed replication timing in strain 9929s, in which the centromere of chromosome 5 was deleted and a neocentromere has formed at a distant location. A replication origin, again the first to replicate, appeared at the site of neocentromere formation. We conclude that centromeres cause their own early and distinct DNA replication timing.
2010-08-31 | GSE17963 | GEO
Project description:Duplication of eukaryotic genomes during S phase is coordinated in space and time. In order to identify zones of initiation and cell-type as well as gender-specific plasticity of DNA replication, we profiled replication timing, histone acetylation and transcription throughout the Drosophila genome. We observed two waves of replication initiation with many distinct zones firing in early and multiple, less defined peaks at the end of S phase, suggesting that initiation becomes more promiscuous at the end of S phase. A comparison of different cell types revealed widespread plasticity of replication timing on autosomes. Most occur in large regions but only half coincide with local differences in transcription. In contrast to confined autosomal differences, a global shift in replication timing occurs throughout the single male X chromosome. Unlike in females, the dosage compensated X chromosome replicates almost exclusively early. This difference occurs at sites which are not transcriptionally hyperactivated, but show increased acetylation of lysine 16 of histone H4. This suggests a transcription-independent, yet chromosome-wide process related to chromatin. Importantly, H4K16ac is also enriched at initiation zones as well as early replicating regions on autosomes during S phase. Together, our data reveal novel organizational principles of DNA replication of the Drosophila genome and imply chromatin structure as a determinant of replication timing locally and chromosome-wide. Keywords: cell type comparison, chip-chip, replication timing
2009-02-10 | GSE13328 | GEO
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (Philip Cayting mailto:pcayting@stanford.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track shows probable binding sites of the specified transcription factors (TFs) in the given cell types as determined by chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq). Each experiment is associated with an input signal, which represents the control condition where immunoprecipitation with non-specific immunoglobulin was performed in the same cell type. For each experiment (cell type vs. antibody) this track shows a graph of enrichment for TF binding (Signal), along with sites that have the greatest evidence of transcription factor binding, as identified by the PeakSeq algorithm (Peaks). The sequence reads, quality scores, and alignment coordinates from these experiments are available for download. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf
2012-04-11 | GSE36030 | GEO