Broad Patterns of Histone Modifications

<div><p>(A) H4K16Ac aligned by ATG. In this representation, the horizontal axis represents location relative to the downstream gene's start codon, and each horizontal line represents one PolII-driven gene. Each cell in the resulting matrix corresponds to the acetylation level at a given microarray probe for one tail position. Red (green) cells mark hyper-acetylated (hypo-acetylated) probes. Non-nucleosomal probes are blackened. We clustered the promoters using a probabilistic agglomerative clustering algorithm (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030328#s4" target="_blank">Materials and Methods</a>). Arrow indicates annotated ATG.</p> <p>(B) H4K16 aligned by transcriptional start site, as in (A), except that arrow indicates TSS (identified in [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030328#pbio-0030328-b29" target="_blank">29</a>]) and data before and after the TSS are aligned by the first nucleosome in that direction.</p> <p>(C) Relationship of histone modification patterns to transcription level. Genes were split into three groups based on PolII enrichment, and averaged data for these groups are shown as indicated, aligned as in (B). Transcription level is indicated by red triangles to the left of each set of three rows.</p>