Cyclic AMP Response Element-Binding Protein/genetics; Dependovirus/genetics; Genetic Vectors/genetics; Nerve Tissue Proteins/genetics; RNA-Binding Proteins/genetics; RNA/genetics; Blotting, Western; Cells, Cultured; Cyclic AMP Response Element-Binding Protein/metabolism; Exons/genetics; Fibroblasts/metabolism; Fibroblasts/pathology; HeLa Cells; Humans; Luciferases/genetics; Luciferases/metabolism; Microscopy, Fluorescence; Models, Genetic; Muscular Atrophy, Spinal/genetics; Muscular Atrophy, Spinal/pathology; Muscular Atrophy, Spinal/therapy; Nerve Tissue Proteins/metabolism; RNA/metabolism; RNA Precursors/genetics; RNA Precursors/metabolism; RNA Splicing/genetics; RNA-Binding Proteins/metabolism; Reverse Transcriptase Polymerase Chain Reaction; SMN Complex Proteins; Survival of Motor Neuron 1 Protein; Survival of Motor Neuron 2 Protein; Transfection/methods