FIG. 5.

In vitro transcription of the hybrid promoter pPE38muTAAG/FR in comparison to pe38 transcription. Plasmids pPE38-CAT57 and pPE38-CAT82, containing wild-type pe38 promoter sequences, and plasmid pPE38muTAAG/FR, containing a pe38/polyhedrin promoter (Fig. 4), were used as templates for in vitro transcription in nuclear extracts of uninfected (lanes u) or AcMNPV-infected S. frugiperda cells prepared at 19 h p.i. (lanes 19) by the method of Gorski et al. (11). In vitro transcription reactions were performed in the presence (lanes +) or absence (lanes −) of α-amanitin (α-ama) (2.5 μg/ml). The extended products were analyzed on a 6% polyacrylamide sequencing gel, and the results of the precise transcriptional mapping are depicted in Fig. 4. The sequencing ladder of the bottom strand of the pe38 promoter is shown on the left.