Fig 4.

The LAT IGr contains at least two bidirectional promoter activities. Complete or half-IGr segments were tested for promoter activity in B. bovis C9.1-parasitized erythrocytes by the dual-luciferase assay. Significant levels of promoter activity were observed with the full-length IGr and with both half-IGr constructs, regardless of the orientation of the sequences relative to the firefly luciferase gene. In vivo transcription start sites of ves1α and ves1β transcripts, observed by a cap-dependent 5′-RACE method, are indicated for comparison. Downward-pointing small triangles, ves1α transcripts; upward-pointing small triangles, ves1β transcripts. Arrows and asterisks are as defined in the Fig. 3 legend.