FIG. 5.

(A) Fiber cross-sectional area in diaphragm muscle myofibers expressing MHC I (type I), MHC IIa (type IIa), and MHC IIb/IIx (type IIb/IIx). Representative fluorescent staining of MHC I (DAPI filter/blue), MHC IIa (FITC filter/green), and dystrophin (Rhodamine filter/red) proteins in diaphragm samples are shown to the right of the graph (n=6/group). Control animals represent acutely anesthetized animals receiving no treatment. Injected animals represent animals receiving intramuscular diaphragm injections of GFP. Values are mean±standard error. No differences existed between groups. (B) Representative images depicting fiber type distribution of control and injected diaphragms. In these images, blue fibers represent MHC type I fibers, green fibers represent MHC type IIa fibers, and nonstained fibers represent MHC type IIb/x fibers. (C) Representative images demonstrating fiber type localization of GFP. MHC, myosin heavy chain.