Figure 1.

Anatomy of mammalian transcripts: functional domains, constitutive and alternative nucleotides and alternative events. TI, transcription initiation site; AUG, translation initiation site; TT, transcription termination site; translation termination site; ATI, alternative transcription initiation; AS, alternative splicing; ATT, alternative transcription termination. Protein-coding regions are filled by black (in cCDSs) or by dark grey (in grey areas). UTRs are shown in white (for UTRs) and in light grey (for grey areas).