Fig. 5

The predicted MMEJ-inducing dnajb6b-sgRNA-injected bag3^e2/e2 F0 adult fish manifested several phenotypic traits that are similar to those in stable bag3^e2/+;dnajb6b^−/− double mutants. (A) Bright-field images of hearts (left panel) and bar graph showing ventricular surface area (VSA) normalized to body weight (BW) (right panel) of fish as indicated. dnajb6b^e6-MJ;bag3^e2/e2 fish exhibited lipid accumulation in the heart (arrows), as well as enlarged VSA/BW levels; n=6, one-way ANOVA. Scale bar: 1 mm. (B) Western blot (top panel) and quantification analysis of ubiquitylated protein levels (bottom panel) in the dnajb6b^e6-MJ;bag3^e2/e2 fish hearts compared to bag3^e2/e2 mutant alone, dnajb6b^e6-MJ or non-injected WT controls at 6 months; n=4, one-way ANOVA. (C) Representative H&E staining of the apex area in fish as indicated (left panel) and quantification of the trabecular muscle density (right panel) in hearts of dnajb6b^e6-MJ;bag3^e2/e2 fish at 6 months compared to that in corresponding controls. The arrow points to lipid droplets; n=6, one-way ANOVA. Scale bar: 100 µM. (D) Confirmative TEM images of dnajb6b^e6-MJ;bag3^e2/e2 fish hearts compared to those of corresponding controls demonstrate severe mitochondrial swelling (arrows) and myofibril degeneration (asterisks) phenotypes that are similar to those detected in hearts of bag3^e2/+;dnajb6b^−/− double-mutant fish. Scale bar: 2 µM; *P<0.05. ns, not significant.