Fig. 1.

Positive feedback vectors. A schematic representation of the positive feedback vector is shown along with the various promoter sequences, reporter cistrons, and ICSes used in these studies. Promoter elements used are a minimal TATA box with one or four copies of a UAS. The reporters used in this study are EGFP and Renilla luciferase. The ICSes are 7-, 8-, and 9-nt versions of an IRES module from the Gtx mRNA (the Gtx nucleotides are shaded), two copies of the 9-nt Gtx IRES module, the HCV IRES, and the N18 sequences.