Figure 4

Distribution of pileup scale versus expression. (a) Two-dimensional normalized histogram of pileup scale versus log gene expression levels for protein coding genes. The first component, stalled Pol2 binding, is indicated on the graph with 'Stalled'. The second component is indicated on the graph with 'Elongating'. (b) Aggregation of Pol2s2 signal around promoters of the genes that are bound by stalled polymerase ('Punctate-Low') and around the promoters of the genes bound with elongating polymerase ('Broad-High').