Fig. 4.

Elements within nt −81 to −5 of the δ-promoter are necessary for activity-dependent regulation. The various slm and internal deletions of the δ −550/+11 promoter are represented schematically, with the numbers indicating the nt bordering regions replaced or deleted. These expression vectors were co-injected with CMVCAT into innervated and denervated EDL muscles. After 1 week, muscles were harvested and Luc and CAT activities were determined. Results are shown with SD and fold differences on the rightside of the figure. Values are reported as a percentage of δ −550 wt expression. Numbers in parenthesis indicate the number of animals injected. p-values (shown in brackets) were calculated using a one-tailed t test.