Fig. 4. Evans blue dye (EBD) uptake is increased in gxi double-mutant mice. (A) EBD is a vital tracer and mutations in the dystrophin and sarcoglycan genes lead to enhanced muscle uptake of EBD. Following injection with EBD, muscles from wild-type (WT), integrin 7 mutant (Itg7^–/–), -sarcoglycan mutant (gsg^–/–) and double mutant (gxi) mice were examined grossly and microscopically where EBD staining appears red. Counterstaining with an anti-dystrophin antibody outlines myofibers (green). Bar, 100 µm. (B) Percentage of EBD-positive fibers in wild-type and mutant mice. EBD uptake is increased in both gxi and gsg^–/– muscle compared to control muscle (P<0.001 and P<0.01, respectively). EBD uptake is increased gxi and gsg^–/– muscle compared to Itg7^–/– muscle (P<0.001 and P<0.05, respectively). EBD uptake is also increased in gxi muscle compared to gsg^–/– muscle (P<0.05).