Fig. 5. Loss of parkin results in indirect flight muscle degeneration. Light microscopy was used to examine IFM architecture. (A-D) Transverse sections through resin-embedded thoraces at 94 hours of pupation and (E-H) at 2 days after eclosion stained with Toluidine Blue to visualize tissue morphology. (A,E) Heterozygous controls show normal IFM architecture. At 2 days post eclosion (F), but not at the late pupal stage (B), parkin mutants show loss of muscle tissue (asterisks). At 11 days (I-L) the muscle loss becomes much more pronounced (compare J with F and L with H). This phenotype is rescued by the dpkR (C,G,K) but not dpkSR (D,H,L).