Morphological perturbations induced by desmin mutants in tibialis anterior muscles. (A) Hematoxylin and eosin staining, (B) succinate dehydrogenase (SDH) staining, (C) immunostaining against c-Myc (green) and perlecan (red), and (D) immunostaining against c-Myc (green); on serial transversal (A, B and C) and longitudinal (D) sections of tibialis anterior muscles expressing WT, R406W or E413K desmin. All analyses were performed 1 month after intramuscular injection of AAV vectors. Note that expression of WT desmin does not seem to modify neither muscle morphology (A to B) nor desmin localization (C to D), whereas expression of R406W and E413K desmin mutants induces accumulation of the desmin in the perinuclear region (see arrowheads). Arrows in (B) illustrate abnormal accumulation of mitochondria observed in both R406W and E413K expressed tibialis anterior muscles. Arrow in (C) illustrates a weaker accumulation of desmin in the case of E413K desmin. Asterisks indicate centronucleated muscle fibers. Nuclei (blue) were stained using DAPI (C to D). Scale bars = 30 μm. AAV, adeno-associated virus; DAPI, 4′,6-diamidino-2-phenylindole; SDH, succinate dehydrogenase; WT, wild-type.