Fig. 6

Modifications associated with transcription elongation follow the transcriptional status of bidirectional genes in H1 ES cells. Cumulative enrichment of transcription elongation associated histone marks at all bidirectional gene pairs separated by one nucleosome distance. The gene pairs are classified into symmetrically or asymmetrically expressed gene pairs based on transcript abundances of each gene in the pair relative to its partner as described in ‘ Methods’. Cumulative expression is calculated by summation of fold enrichment signal at every location in a 4 Kb window for each category and dividing by the highest value of signal in the respective category as described in ‘Methods’. ChIP-seq data for two different Histone modifications associated with transcription elongation was analyzed, namely H3K79me1 (a, n = 117; b, n = 319) and H3K36me3 (c, n = 189; d, n = 264). Unidirectional genes were used as a control such that the number of unidirectional genes is equal to the number of bidirectional gene pairs plotted. The expression range of uni-directional genes chosen is identical to the bidirectional dataset. (e, n = 500) Cumulative enrichment of H3K79me1 on unidirectional promoters. (f, n = 500) Cumulative enrichment of H3K36me3 on unidirectional promoters. The genes transcribed on the plus and minus strands are denoted by the blue and brown colored lines respectively for the asymmetrically expressed genes. For the symmetrically expressed genes, genes that are silent are represented as the black line whereas the genes expressed from both strands are depicted with the red line. For unidirectional genes, the black and red lines represent the genes transcribed from the plus and minus strand respectively