Figure 5.

Expression of β-gal in TA muscle fibers after injection of a plasmid containing the reporter gene lacZ with and without the intronic fragment placed in either orientation (r = reverse) upstream of the thymidine kinase (TK) promoter. Note the significant (P < 0.001; ANOVA) ≈6-fold induction in β-gal activity with the presence of the intronic DNA fragment in either orientation. Expression of β-gal was normalized to the activity of a coinjected CAT plasmid used to monitor transduction efficiency. Mean ± SE is shown; a minimum of 12 muscles were analyzed per construct.