Different approximation pattern of bidirectional pairings. (A) Overview of the minigene constructs used to mimic the approximation of sequences caused by the Us-to-Dd pairing (stem II). A cross in Us or Dd denotes the disrupting mutation. Symbols used are the same as those in Figure 1. (B) Effects of exon 4.1 selection by a series of deletions and mutations. The band marked by “*” is a nonspecific RT-PCR product. (C) Quantization of the data in B. Data are expressed as percentages of the mean ± SD from three independent experiments. (**) P < 0.01, (***) P < 0.001 (Student's t-test, two-tailed). These data indicate that RNA pairing interactions function to approximate upstream and downstream sequences. (D) Overview of the minigene constructs used to evaluate the importance of approximating sequences caused by Ud-to-Ds pairing (stem I). (E) Effect of a series of deletions and mutations on exon 4.2 inclusion. (F) Quantization of the data in E.
