Figure 2. Cardiomyocyte-specific Ncoa6 deficiency impairs cardiac ultrastructures and mitochondrial function in mice.

(A) TEM analysis of left ventricles from 3-month-old f/f and Δ/Δ female mice. Scale bars, 2 ìm; arrowheads, Z-discs; arrows, mitochondria.

(B and C) Quantification of the number of mitochondria per 36 ìm² calculated from three independent TEM images (B) and mtDNA contents (C) by Southern blot analyses in the hearts of 3- month-old male and female mouse ventricles (n = 3 for each genotype). Graphs show means ± s.d.; *P < 0.05; ***P < 0.001.

(D) Analyses of mitochondrial rRNAs (12S and 16S), mRNAs (ND1 and COXI), and tRNAs (F, L1, P, C, and Q) by Northern blot. P < 0.05 for all mtRNA. Left ventricles of 3- to 5-month-old male and female mice (n = 3 for each genotype) were used.

(E) Analysis of mitochondrial respiratory chain complexes II, III, and V by Western blot (left) and its quantitative ratios (right) of each complex to Lamin A (LMNA). Left ventricles of 3- to 5-month-old male and female mice (n = 3 for each genotype) were used. LMNA was used as a loading control. Graphs show means ± s.d.; **P < 0.01; ***P < 0.001.

(F) Analysis of mitochondrial complex II activity in 2- to 3-month-old mice (male, n = 3; female, n = 4 for each genotype). mOD, mitochondrial optical density. Graphs show means ± s.d.; **P < 0.01.