Figure 1.

Modes of alternative splicing. (a) Exon skipping. (b) Mutually exclusive exons. (c) Intron retention. (d) Alternative 5′ ss. (e) Alternative 3′ ss. Lines indicate introns; blue bars indicate constitutive exons; green and orange bars indicate alternative spliced exons; dotted arrows indicate splicing events; dotted vertical lines indicate alternative splice sites.