The effect of MuLV LTR on

mdr1a promoter (luciferase-reporter assay). The blank, filled, and shadowed boxes correspond to dragonfly luciferase cDNA, exon-1 and exon-2 of mdr1a, and the MuLV LTR sequence, respectively. The filled arrow shows the transcriptional start and direction of the mdr1a gene. The average value of relative luciferase activity is indicated in the shaded column, and the number of assays performed is indicated in parenthesis.