Fig. 2.

Structure and cloning of bicistronic AAV-shRNA/TuD vectors. (Upper) The general vector design with the two independent shRNA and TuD expression cassettes, together with selected unique restriction sites and stretches of six thymidines that serve as termination signal for RNA polymerase III promoters (H1 or U6). Both cassettes together are flanked by ITRs from AAV serotypes 2 or 4 [the asterisk indicates a truncation that mediates the self-complementary genotype (4)] for packaging into AAV particles. (Lower) A magnification of the two inverted BbsI or BsmBI sites (bold) that are used for cloning of shRNAs or TuDs, respectively, as annealed or extended oligonucleotides with the indicated overhangs.