FVII minigene construct and modified U1-snRNAs. (A) Schematic representation of the expression cassette cloned into pCDNA3. The entire region was sequenced to exclude undesired sequence variations. Primers for RT-PCR (6F, 7FF, 7F, 8R′, 8R) are indicated by arrows. The 37bp IVS7 repeats are boxed, and the asterisk represents the 5′ss cryptic site in the first repeat. The 5′ss consensus sequence and the 9726 + 5g/a change (bold) is shown at the top. (B) Schematic representation of the IVS7 repeats and of the U1-snRNA secondary structure. The 5′ tail of U1-snRNAs was engineered to bind to different regions at or near the mutated IVS7 5′ss, and their sequence complementarity is underlined. Complementarity of U1 + 5a is shown at the top. The asterisk and the corresponding boxed nucleotide in the first repeat represent the 5′ss cryptic site.
