Changes over time in H3K27 tri-methylation at the TSS of genes showing specific transcriptional responses to VPA and at other genomic regions. a Levels of H3K27me3, after increasing time in 1 mM VPA, at the TSS of genes involved in the four categories of persistent transcriptional response (Fig. 2), as indicated. TSS probes were −500 to +500 bp around each TSS and were quantified by read count, normalised to the largest datastore. b Levels of H3K27me3, after increasing time in 1 mM VPA, at different genomic regions. 1,000 bp rolling windows were quantified by read count quantitation, normalised to the largest datastore. The distribution of all probes and those overlapping with TSS, not overlapping with TSS or overlapping coding sequence are shown. c Screenshot from SeqMonk showing changes in H3K27me3 and H3K27ac at and around the TSS of the NBPF15 gene. The positions of the gene and the coding sequence are indicated across the top of the panel. Forward reads are shown in red and reverse in blue. The coloured boxes below each data track show the position and value (box height) of each TSS probe.