Figure 6From: Construction and characterization of new piggyBac vectors for constitutive or inducible expression of heterologous gene pairs and the identification of a previously unrecognized activator sequence in piggyBacEffects of introducing BGHPolyA to arrest potential antisense transcription. The genetic structures of the different piggyBac vectors assayed in this experiment (A-F) are shown at the top, with the dual constitutive (ie1-hr5-ie1) transcriptional control elements indicated by open boxes, the dual inducible (P CMVmin -TetO7-P CMVmin ) transcriptional control element indicated by horizontally striped boxes, the orientations of the various heterologous genes shown, and the newly introduced BGHPolyA site marked with a star. The rightward-oriented arrow marked with a question mark depicts the hypothesis that antisense transcription originating in the 5'-TRD region could down-regulate expression of the leftward-facing heterologous genes. The plot shows the relative GalT activity levels induced by each of the indicated piggyBac vectors, together with the background levels determined using extracts of mock-transfected Sf9 cells (None).Back to article page