Figure 4

RNA-seq demonstrates precision of TSS relative to first splice junction. (a, b) Overhead view of individual profiles of RNA-seq signal normalized to self-maximum, grey-shaded as in Figure 1 (paired-end read coverage pileup, STAR mapping) sorted vertically by the length of the first exon. (a) Signal aligned by TSS and (b) aligned by first splice junctions (2,790 expressed and isolated genes and without the top 10% highest signal genes). (c, d) Averaged profiles of RNA-seq, (c) aligned by TSS and (d) aligned by first junction. These are simply the mean profiles computed from the set of profiles in (a) and (b). a.u., arbitrary units.