Figure 1

Schematic illustration of alternative splicing. A) Exon skipping. Gene A forms two different transcripts; the first transcript has a new exon compared to the second transcript, the new exon is an inclusive exon, and the other two exons are constitutive. B) Intron retention. Gene B forms two different transcripts; the second transcript is a new exon formed from retained intron and exons on both sides. C) Alternative donor site. Gene C forms two different transcripts; the difference is one exon of an alternative 5′ splice site of the second transcript extended. D) Alternative acceptor site. Gene D forms two different transcripts; the difference is one exon of the alternative 3′ splice site of the second transcript extended. E) Mutually exclusive exon. Gene E forms two different transcripts; the different exon is an inclusive exon, the same exon is a constitutive exon, and two transcripts have different inclusive exons.