FIGURE 2.
Deletion mutagenesis of the B1 region leads to the discovery of three novel splicing regulating elements. A, locations of the deletions are indicated by the bars, and their sizes are shown in nucleotides. B, radiolabeled RT-PCR assays on total RNA extracted from HeLa cells transfected with the different deletion mutations. After separation on acrylamide gels, the bands were analyzed using a PhosphorImager. The corresponding Bcl-xL and Bcl-xS bands are shown, as well as the Bcl-xL/Bcl-xS ratio displayed above the lane numbers. The results presented are representative of many independent experiments.