Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (mailto:nshoresh@broad.mit.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track displays maps of chromatin state generated by the Broad/MGH ENCODE group using ChIP-seq. Chemical modifications (methylation, acetylation) to the histone proteins present in chromatin influence gene expression by changing how accessible the chromatin is to transcription. The ChIP-seq method involves first using formaldehyde to cross-link histones and other DNA-associated proteins to genomic DNA within cells. The cross-linked chromatin is subsequently extracted, mechanically sheared, and immunoprecipitated using specific antibodies. After reversal of cross-links, the immunoprecipitated DNA is sequenced and mapped to the human reference genome. The relative enrichment of each antibody-target (epitope) across the genome is inferred from the density of mapped fragments. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf ChIP-seq: Cells were grown according to the approved ENCODE cell culture protocols. Cells were fixed in 1% formaldehyde and resuspended in lysis buffer. Chromatin was sheared to 200-700 bp using a Diagenode Bioruptor. Solubilized chromatin was immunoprecipitated with antibodies against each of the histone antibodies listed above. Antibody-chromatin complexes were pulled-down using protein A-sepharose (or anti-IgM-conjugated agarose for RNA polymerase II), washed and then eluted. After cross-link reversal and proteinase K treatment, immunoprecipitated DNA was extracted with phenol-chloroform, ethanol precipitated, treated with RNAse and purified. One to ten nanograms of DNA were end-repaired, adapter-ligated and sequenced by Illumina Genome Analyzers as recommended by the manufacturer. Alignment: Sequence reads from each IP experiment were aligned to the human reference genome (GRCh37/hg19) using MAQ with default parameters, except '-C 11' and '-H output_file', which outputs up to 11 additional best matches for each read (if any are found) to a file. This information was used to filter out any read that had more than 10 best matches on the genome. Note: It is likely that instances where multiple reads align to the same position and with the same orientation are due to enhanced PCR amplification of a single DNA fragment. No attempt has been made, however, to remove such artifacts from the data, following ENCODE practices. Signal: Fragment densities were computed by counting the number of reads overlapping each 25 bp bin along the genome. Densities were computed using igvtools count with default parameters (in particular, '-w 25' to set window size of 25 bp and '-f mean' to report the mean value across the window), except for '-e' set to extend the reads to 200 bp, and the .wig output was converted to bigWig using wigToBigWig from the UCSC Kent software package. Peaks: Discrete intervals of ChIP-seq fragment enrichment were identified using Scripture, a scan statistics approach, under the assumption of uniform background signal. All data sets where processed with '-task chip', and with '-windows 100,200,500,1000,5000,10000,100000'. (No mask file nor the '-trim' option have been used.) The resulting called segments were then further filtered to remove intervals that are significantly enriched only because they contain smaller enriched intervals within them. This post-processing step has been implemented using Matlab. The use of the post-processing step allowed very large enriched intervals (of the order of Mbps for H3K27me3, for instance) to be detected, as well as much smaller intervals, without the need to tailor the parameters of Scripture based on prior expectations.
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (mailto:nshoresh@broad.mit.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track displays maps of chromatin state generated by the Broad/MGH ENCODE group using ChIP-seq. Chemical modifications (methylation, acetylation) to the histone proteins present in chromatin influence gene expression by changing how accessible the chromatin is to transcription. The ChIP-seq method involves first using formaldehyde to cross-link histones and other DNA-associated proteins to genomic DNA within cells. The cross-linked chromatin is subsequently extracted, mechanically sheared, and immunoprecipitated using specific antibodies. After reversal of cross-links, the immunoprecipitated DNA is sequenced and mapped to the human reference genome. The relative enrichment of each antibody-target (epitope) across the genome is inferred from the density of mapped fragments. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf
Project description:The readout of genome information is controlled by transcriptional regulatory elements, but a comprehensive view of the combinatorial control by these DNA sequences, which bind regulatory protein and/or the modified histones in regulating gene transcription, is clearly preliminary. We have developed an experimental strategy for comprehensive determination of such functional elements in human DNA. This strategy involves the application of genome-wide location analysis, also known as ChIP-chip, to a panel of well-characterized regulatory proteins and histones with specific modifications, known to generally associate with transcriptional regulatory elements in vivo. Identification of their genomic binding sites will allow us to determine the sequence features in the human genome that carry out transcriptional regulatory function. We have designed and produced DNA microarrays to represent all the non-repetitive sequences in the 30 million basepair ENCODE regions of the human genome to map various types of transcriptional regulatory elements in three model cell types. We have identified promoters by mapping the genomic sequences associated with RNA polymerase II and the general transcription factor TFIID in cells, enhancer elements by mapping the genomic sequences associated with transcriptional co-activators and enhancer-specific chromatin modifications, and insulators by mapping the genomic sequences associated with the insulator binding protein CTCF. The raw microarray results are released periodically prior to publication. Keywords: ChIP-chip
Project description:The readout of genome information is controlled by transcriptional regulatory elements, but a comprehensive view of the combinatorial control by these DNA sequences, which bind regulatory protein and/or the modified histones in regulating gene transcription, is clearly preliminary. We have developed an experimental strategy for comprehensive determination of such functional elements in human DNA. This strategy involves the application of genome-wide location analysis, also known as ChIP-chip, to a panel of well-characterized regulatory proteins and histones with specific modifications, known to generally associate with transcriptional regulatory elements in vivo. Identification of their genomic binding sites will allow us to determine the sequence features in the human genome that carry out transcriptional regulatory function. We have designed and produced DNA microarrays to represent all the non-repetitive sequences in the 30 million basepair ENCODE regions of the human genome to map various types of transcriptional regulatory elements in three model cell types. We have identified promoters by mapping the genomic sequences associated with RNA polymerase II and the general transcription factor TFIID in cells, enhancer elements by mapping the genomic sequences associated with transcriptional co-activators and enhancer-specific chromatin modifications, and insulators by mapping the genomic sequences associated with the insulator binding protein CTCF. The raw microarray results are released periodically prior to publication. Keywords: ChIP-chip ENCODE
Project description:The readout of genome information is controlled by transcriptional regulatory elements, but a comprehensive view of the combinatorial control by these DNA sequences, which bind regulatory protein and/or the modified histones in regulating gene transcription, is clearly preliminary. We have developed an experimental strategy for comprehensive determination of such functional elements in human DNA. This strategy involves the application of genome-wide location analysis, also known as ChIP-chip, to a panel of well-characterized regulatory proteins and histones with specific modifications, known to generally associate with transcriptional regulatory elements in vivo. Identification of their genomic binding sites will allow us to determine the sequence features in the human genome that carry out transcriptional regulatory function. We have designed and produced DNA microarrays to represent all the non-repetitive sequences in the 30 million basepair ENCODE regions of the human genome to map various types of transcriptional regulatory elements in three model cell types. We have identified promoters by mapping the genomic sequences associated with RNA polymerase II and the general transcription factor TFIID in cells, enhancer elements by mapping the genomic sequences associated with transcriptional co-activators and enhancer-specific chromatin modifications, and insulators by mapping the genomic sequences associated with the insulator binding protein CTCF. The raw microarray results are released periodically prior to publication. Keywords: ChIP-chip ENCODE
Project description:The readout of genome information is controlled by transcriptional regulatory elements, but a comprehensive view of the combinatorial control by these DNA sequences, which bind regulatory protein and/or the modified histones in regulating gene transcription, is clearly preliminary. We have developed an experimental strategy for comprehensive determination of such functional elements in human DNA. This strategy involves the application of genome-wide location analysis, also known as ChIP-chip, to a panel of well-characterized regulatory proteins and histones with specific modifications, known to generally associate with transcriptional regulatory elements in vivo. Identification of their genomic binding sites will allow us to determine the sequence features in the human genome that carry out transcriptional regulatory function. We have designed and produced DNA microarrays to represent all the non-repetitive sequences in the 30 million basepair ENCODE regions of the human genome to map various types of transcriptional regulatory elements in three model cell types. We have identified promoters by mapping the genomic sequences associated with RNA polymerase II and the general transcription factor TFIID in cells, enhancer elements by mapping the genomic sequences associated with transcriptional co-activators and enhancer-specific chromatin modifications, and insulators by mapping the genomic sequences associated with the insulator binding protein CTCF. The raw microarray results are released periodically prior to publication. Keywords: ChIP-chip ENCODE