Fig. 4. Overexpression of Dp116 on a wild-type background has dominant-negative effects. (A) Cross sections of quadriceps muscle from Dp116 transgenic mice and C57Bl/6 controls. Immunofluorescence staining with antibodies specific to the dystrophin N-terminal domain and the Flag epitope demonstrate decreased expression of full-length dystrophin but high levels of Dp116 on the sarcolemma of transgenic muscles. Hematoxylin and eosin staining shows increased numbers of muscle fibers with central nuclei in the transgenic quadriceps. Bar, 100 µm. (B) Western analysis using a monoclonal antibody specific for the dystrophin C-terminus confirms reduced amounts of full-length dystrophin protein in various skeletal muscles of transgenic mice compared with controls. An identical gel stained in parallel with Coomassie Blue is shown as a loading control. D, diaphragm; Q, quadriceps; S, soleus; TA, tibialis anterior; N, peripheral nerve.