Gasp1 overexpression induces a marked muscle fiber hypertrophy. Sections were prepared from rectus femoris muscles of wild-type or surGasp1-20 mice and stained by hematoxylin-eosin (A, B), silver impregnation (C, D) or myosin ATPase stain with acidic preincubation (E, F). (G) Overall muscle fiber cross-sectional area of wild-type or surGasp1-20 rectus femoris muscles. (H) Distribution of muscle fiber sizes in wild-type (dark grey) or surGasp-1-20 (light grey). *** Statistically significant compared to control, p < 0.001.