Figure 3.

Splicing in vitro of RNA containing the intron and surrounding sequences from TN23 (lanes 1–3) and TN24 (lanes 4–6). (A) Diagram of substrates. (B) Transcripts were incubated in splicing reactions for 0 (lanes 1 and 4), 30 (lanes 2 and 5) or 60 (lanes 3 and 6) min and analysed by electrophoresis on denaturing gels. The precursor is marked, together with the 5′ exon intermediate and mRNA product derived by use of the 5′ splice site at 6171/6172. The lower mobility lariats and the mRNA at the foot of the panel are derived from use of the site at position 6079/6080.