Histopathology and αB-crystallin insolubility in αB-R120G knock-in mice.

<p><i>A)</i> Additional staining of 10-month-old αB-crystallin R120G homozygous mouse TA with Congo red shows multiple congophilic inclusions (<i>red; open arrows</i>). Cytochrome oxidase staining (<i>brown</i>) is absent or cleared from the central region of scattered myofibers (<i>starred fibers</i>). Immunofluorescence using an antibody against ubiquitinated proteins (<i>red</i>) highlights large ubiquitinated aggregates within scattered fibers. Blue staining is nuclear DNA. Scale bar is 50 µm. <i>B)</i> Triple immunofluorescence staining of TA muscle from 10-month-old wild-type or αB-R120G homozygous mutant mice using anti-αB-crystallin (<i>green</i>), anti-desmin (<i>red</i>), or anti-ubiquitin (<i>red in bottom right panel only</i>), and nuclear DNA (<i>blue</i>). Open arrowhead shows αB-crystallin and desmin co-aggregate, while closed arrowhead denotes isolated desmin inclusion. Individual myofibers are outlined in white. Scale bar is 50 µm. <i>C)</i> Immunoblot using αB-crystallin antibody of total, detergent-soluble, or detergent-insoluble proteins from TA muscle lysates of 4.5-month-old wild-type (<i>WT</i>), αB-R120G heterozygous (<i>het</i>), or homozygous (<i>homo</i>) mutant knock-in mice. Histopathology was performed on at least two mice per age.