Identification of the putative alternative promoters in human genes. Schematic representation of the mapping of the 5′-ends of the oligo-cap cDNAs, the determination of the TSSs, and clustering of the TSSs to identify the PAPs. The boxes and lines represent exons and introns, respectively. The RefSeq sequences and the oligo-cap cDNAs are in red and blue, respectively. The lowest gray oligo-cap cDNA is excluded from the data set, since its 5′-end is located within an internal exon of the RefSeq. The third-lowest oligo-cap cDNA is accepted because the truncation of the erroneously sliced second-lowest transcript would otherwise need to be hypothesized to explain its presence, and the chance of the combination of such events should be low. The shaded boxes represent the retained introns. Altogether, this case consists of 8 “full-length” oligo-cap cDNAs that are mapped at 6 TSSs, clustered into 3 PAPs.
