Fig. 1.

Different types of alternative splicing. a Exon skipping. b Alternative 3′ SS selection. c Alternative 5′ SS selection. d Intron retention. e Mutually exclusive exons. f Alternative promoters. g Alternative poly (A). (Form e, f, g and other trans forms (not shown) categorized as a complex events). In the figure, constitutive exons are shown in blue and alternatively spliced regions in purple. Introns are represented by solid lines and dashed lines indicate splicing options