Peak distribution across the transcriptome. The peak distribution depicted is the average across the entire transcriptome. Peaks are mapped to transcripts and assigned to the following transcriptomic features: 1 kB upstream from the TSS and downstream from the transcription end site, 5' and 3' UTRs, coding segments (CDS), and exon and intron segments. In the bottom row, peaks mapping to transcripts with four or more exons are shown, with the first, penultimate and last exons separated into individual boxes, as are their neighboring introns. The remaining exons and introns are shown in the middle boxes as a contiguous segment. Genes with only two or three exons are shown in the middle row and single exon genes are shown in the top row. Data from  and .