FIGURE 3:

Mitochondrial crista structure and function are impaired in dMIC60^mut. (A, B) TEM images of thin sections, performed on the body wall muscles of late third instar larvae. (A) The right panel is a higher magnification image of the mitochondrion marked by the green-lined box in the left. Scale bars: 500 nm. (C) Representative confocal images of TMRM staining in NMJ boutons at muscle 4 of third instar larvae. Red is TMRM staining in polarized mitochondria, green is MitoTracker Green staining in all mitochondria, and blue is horseradish peroxidase (HRP) on bouton membranes. To the right is quantification of the TMRM/MitoTracker Green fluorescence intensity in boutons as shown. The values are normalized to the mean of “Wild-type” or “elav-GAL4.” n = 11–14 NMJs from five to six larvae. Scale bar: 10 μm. (D) Quantification of the total ATP level in 48-h APF pupae, expressed as a percentage of the wild-type values. Comparisons with “Wild-type.” n = 5 pupae for each experiment and total six independent experiments. (E) The mitochondrial size is quantified between genotypes by measuring the mitochondrial area, and the mitochondrial shape is quantified by measuring the mitochondrial aspect ratio (dividing the minor diameter by the major diameter) of a mitochondrion, using Image J from the 10,000 × TEM images. n = 20–25 mitochondria from 12–15 images from four to five larvae. (F) Immunogold TEM images of thin sections, performed on the body wall muscles of late third instar larvae, show mitochondrial DNA clusters exampled by red arrowheads. Scale bars: 100 nm.