Fig. 7. In vitro splicing of the SC35 cassette exon. The wt-CE (left panel) and the βGlo-CE (right panel) pre-mRNAs were spliced in the presence of nuclear extracts alone or supplemented with the individual SR proteins as in Figure 6. Lanes 1 and 6, pre-mRNA starting material; lanes 2 and 7, splicing assays with the nuclear extract alone. In the right panel, 7 and 14 pmol are used for SC35, ASF/SF2 and SRp46, and 10 pmol for 9G8. In the left panel, the higher amount of each SR protein was used. At the bottom of the right panel, two small zones, only including the 3- or 2-exon mRNA, are shown. The positions of the RNA products are indicated at the side of both panels.