Figure 5. Reporter gene activity from a nested deletion series of the 5' flanking region of the murine IRBP promoter.

Various lengths of the full-length (1783 bp) IRBP 5' flanking region were inserted into CAT plasmid constructs and transfected into primary cultures of embryonic day 10 chick retina cells as described in the text. The lengths of the promoter fragments are given below the activities. Following four days of incubation, cells were harvested and assayed for CAT activity as a measure of promoter activity. Only activities from p45 and pBLCAT3 are significantly less than that of p1783 (p < 0.05). The data are from nine experiments. Activities are means ± SEM of percentage of p1783 from individual experiments. Sample size is indicated in parentheses above error bars.