Figure 3: Relative promoter activity of PromoterLong and PromoterShort in nondifferentiated and cardiomyocyte-differentiated P19CL6 cells. Constructs containing different lengths of the putative promoter region of mouse RhoA (PromoterLong and PromoterShort) were cloned upstream of the firefly luciferase coding sequence in pGL3-Basic and cotransfected with the pRL-TK coreporter vector (expresses Renilla luciferase) into nondifferentiated and differentiated P19CL6 cells 11 days after DMSO induction. The firefly luciferase activity of each sample (expressed as relative light units) was normalised to the Renilla luciferase activity and expressed as this ratio (fold luciferase activity). The data represents the mean ± SEM of six individual transfections for each construct. compared to activity in nondifferentiated cells (Student’s -test).