I know that alternative polyadenylation creates different transcript isoforms. My question is whether alternative polyadenylation ever results in differences in the terminal/last exon? The only case I can think where it might be is if the terminal exon is alternatively spliced?
EDIT: I think what I was trying to ask was for a given gene, what factors could cause the transcripts to end in different locations. I drew a picture and it helped me figure it out a little Here are 4 transcripts for a given gene, each of which end at a different location. Exon's C and D end in different locations because D is completely different exon than C that is being spliced to exon B. Exon on C and E start at the same location, but exon E is shorter, due to a UTR-Alternative polyA event. Exon B and F start at the same location, but F is shorter due to a Coding APA change. So alternative polyadenylation drives the formation of transcripts 1,3,4 while alternative splicing drives the formation of transcript 2. So I guess to rephrase my question, are there any other biological process that can affect where a transcript ends