Fig. 5

BiP accumulation is also responsible for the impaired mitochondrial dynamics. Live images of 6 dpf DMSO- (A and B), tunicamycin- (Tm-) (C and D), or thapsigargin-treated (Tg-treated) (E and F) larvae showing mosaic expression of actc1b:mitoGFP labeling the mitochondria in green. While DMSO-treated larvae display small mitochondria, some of which form an intricate network, mitochondria in Tm- and Tg-treated larvae were large and rounded, as determined using a ?2 test. B, D, and F (scale bar: 15 ?m) are zoomed in views of A, C, and E (scale bar: 100 ?m), respectively. (G) The proportion of muscle fibers displaying altered mitochondrial morphology following DMSO, Tm, or Tg treatment, determined using a ?2 test. (H?O) Live images of 6 dpf larvae coexpressing Mito-GFP with mCherry (H?K) or BiP-mCherry (L?O). K and O are zoomed in views of J and N, respectively. Scale bar: 150 ?m (first, second, and third columns); 15 ?m (last column). (P) The proportion of muscle fibers displaying altered mitochondrial morphology comparing mCherry overexpression with BiP overexpression, as per Fisher?s exact test. (Q and R) Live images of 6 dpf atrogin-1?/? mutant larvae on the Tg(actc1b:KalTA4;cryaa:GFPpc54Tg) only (labeled as Control (KaltA4)) or Tg(actc1b:KalTA4;cryaa:GFPpc54Tg) and Tg(4XUAS:NLSCas9;cmlc2:RFP gl37Tg) (labeled as BiP KO) background, showing mosaic expression of actc1b:mitoGFP labeling the mitochondria in green. While control atrogin-1?/? mutants display large and rounded mitochondria, atrogin-1?/? mutants with BiP deficiency specifically in the muscle have small mitochondria that form an intricate network, as determined using a ?2 test. Scale bar: 100 ?m. (S) The proportion of muscle fibers displaying altered mitochondrial morphology in control and BiP-KO atrogin-1?/? mutants, as per Fisher?s exact test. *P < 0.05, ***P < 0.001. All experiments performed in triplicate with the total number of fish examined in each replicate being documented in Supplemental Table 2.