Ultrastructure of diaphragm from dystrophic α-sarcoglycan-null mice

lead to muscular dystrophies: Duchenne/Becker dystrophy, associated to dystrophin protein defects, congenital dystrophy, due to laminin-2 absence, and sarcoglycanopathies, a subset of limb-girdle muscular dystrophies (LGMD) related to deficiency of the sarcoglycans (Straub & Campbell, 1997). Mutations in the α-sarcoglycan gene (Sgca), causing the lack or alterations of the protein, are responsible for type 2D LGMD, an autosomal-recessive severe human muscular disorder (Roberts et al., 1994). Animal models of human dystrophies are widely used to investigate pathogenesis, physiopathology, and treatment of these disorders (Durbeej & Campbell, 2002). Sgca-null mice have been generated recently, showing a milder pathological phenotype than the human disorder (Duclos et al., 1998; Liu & Engvall, 1999). Histological analysis of hind-limb muscles showed dystrophic features that progress with age (Duclos et al., 1998). The ultrastructure of those dystrophic muscles has not Ultrastructure of diaphragm from dystrophic α-sarcoglycan-null mice