Fig. 6

Confocal images of cardiotoxin-damaged STM muscles from young adult RG mice. a-c A maximum intensity projection of whole mounted muscle fibers one day post-CTX injury. a AChRs largely retain their uninjured morphology. b The mCherry labeled myonuclei are entirely absent from the myofibers 1 day post-myofiber damage. c An abundance of DAPI-stained nuclei resides within the muscle tissue. d-f Whole-mounted muscle fibers 7 days post-CTX injury. d AChRs 7 days after injury have taken on the fragmented phenotype (arrows) common to regenerated myofibers. e Seven days after injury, mCherry labeled myonuclei re-appear in long strings located in the center of the myofibers. Asterisks indicate examples of strings of central myonuclei. f The numerous strings of central myonuclei stain with DAPI. g-j Single plane confocal image of a 20 μm cross-section of muscle fibers 7 days post-CTX injury. g Transgenic myonuclear label. Asterisks indicate centrally positioned myonuclei. h Sarcolemmas stained with anti-dystrophin antibody reveal the boundaries of myofibers. i DAPI labeling of all nuclei in muscle tissue. j Composite image. Asterisks correspond to those in g. Scale bars 20 μm