Figure 5.
Caudal is a DPE-specific transcriptional activator. (A) Caudal preferentially activates transcription through the DPE in the gt core promoter. The reporter constructs contain six Caudal-binding sites upstream of the gt core promoter, which has both DPE and TATA motifs but lacks a BREu. The constructs are identical except for the mutation of the TATA and DPE motifs and the addition of the AdML BREu, where indicated. The transfection experiments were performed as in Figure 3. Error bars represent the SEM. (B) Caudal primarily activates through the DPE in the natural ftz transcriptional control region. The ftz core promoter contains both DPE and TATA motifs. The reporter constructs contain ftz enhancer and promoter sequences from −988 to +40 relative to the +1 start site, and are identical except for mutation of the DPE or TATA, as depicted. The transfection experiments were performed as in Figure 3. Error bars represent the SEM.