Experimental model for exon 16 erythroid-regulated splicing.

(A) Minigene construct. Exon 16 is inserted as an internal exon, together with its flanking intron sequences in the 4.1R cassette p(13,17)/CMV (WT construct). DNA fragment sizes are given in base pairs. (B-C) Differential splicing of transfected exon 16. (B) Semiquantitative RT-PCR analysis on polyacrylamide gel electrophoresis. The +16 and −16 indicate the inclusion or exclusion of exon 16, respectively. Neg indicates negative. (C) RPA using probe H(13,16). Mock uninduced (1) and induced (2) MEL cells; uninduced (3) and induced (4) MEL cells transfected with WT construct; uninduced (5) and induced (6) MEL cells transfected with the p(13,17)/CMV cassette without the 0.7-kb exon 16 fragment. Y, yeast RNA; M, size markers; P, undigested probe. The lower diffused band corresponds to the endogenous 4.1R mRNA.