Figure 7.

Exons belonging to clusters of multiple promoters and multiple poly(A) sites in the Drosophila melanogaster X chromosome. The figure shows the number of multiple promoter exons and multiple poly(A) sites exons based on the Flybase annotation and illustrates how many of these exons share the following features: high sequence similarity, similar length, same reading frame, and a minimal exon length (15 residues). Blue slices indicate exons characterised by these features, and red slices indicate exons not sharing these features.