<i>In vivo</i> strength and muscle histopathology in αB-R120G knock-in mice.

<p><i>A</i>) Average grip strength of αB-R120G heterozygous (n = 27), homozygous (n = 20), or wild-type (n = 10) control littermates at ∼6 months of age. *p<0.05. <i>B)</i> H&E or modified Gomori trichrome (mGT) staining of tibialis anterior (TA) muscle from 10-month-old wild-type, αB-R120G heterozygous, or αB-R120G homozygous mutant mice. <i>H&E</i>, evidence of myopathy in mutant muscle with small angular fibers (<i>open arrowhead</i>) and internal nuclei (<i>closed arrowhead</i>). <i>mGT</i>, increased dark staining consistent with the accumulation of myofibrillar proteins (<i>arrows</i>) in mutant muscle. Scale bar is 50 µm.