Fig. 4.

Relative sense strand promoter activity of sequences from D. melanogaster TART elements tested in D. melanogaster cells. Gray bar diagram at top shows the putative 5′ PNTR of TART, ending in the first few nucleotides of the Gag ORF. This ORF was replaced with a reporter gene to make constructs testing promoter activities in the 5′ PNTR (see text). Those constructs are shown below the diagram. The lower gray bar diagram shows the same sequence with the ORF replaced by the post-PNTR sequence plus terminal oligoA (thin black line). The reporter gene follows the oligoA to test the effect of termination sequences on the promoter in the 3′ PNTR. Shown below each PNTR diagram are sequences tested, identified by nucleotide number at either end. Nucleotides are numbered from the transcription start site (arrow) identified here and by Maxwell et al. (17). Positive numbers run downstream, and negative numbers run upstream. Activity (±SD) was determined as in Fig. 2.