Patterns of the first exons in the PAP-containing genes. (A) Distributions of the patterns of the first exons are shown. The number of identified exon patterns was counted in total (third column) or between the populations which are separated by >500 bp, thus accounting for the separation of the PAPs. *Either of the first exon variations was a “single exon” transcript. Different criteria were employed for them because these transcripts cannot be regarded as “splicing” variants. (B) Alterations of the amino acids resulting from the exon variations occurring in the population of “inter-APs” (TSS distance >500) or “intra-APs” (TSS distance ≤500) were counted.
