Box plot showing RNA polymerase II elongation indices as estimated by measuring the log ratio of ChIP-Seq reads found in gene bodies over reads in promoters (see Materials and Methods) as previously (Rahl
et al,
2010). Genes were ranked according to the ratio of H3K36me3 over H3K36me2 levels as measured by ChIP-seq (q1/high to q4/low; see Materials and Methods).