FIGURE 6.

Mitochondrial proliferation and altered ultrastructure in taz-deficient mice. A compares mtDNA content with nuclear DNA (nDNA) content in various tissues of NTG and taz-deficient mice as a measure of mitochondrial abundance. mtDNA to nuclear DNA ratios as a percentage of NTG controls with S.E. are plotted. B and C, morphometric analyses of mitochondria in cardiac (B) and skeletal (C) muscles. The proportions of cardiac and skeletal muscle mitochondria displaying various structural abnormalities (Figs. 3 and 4) are plotted. Data are means with S.E. of three experiments in each of which we evaluated four or more mitochondrial cross-sections per group. D and E, quantitative morphometric analyses of sarcomere (D) and MAM (E) areas in the cross-sectional micrographs from heart of 8-month-old mice. Numbers are means ± S.E., and the numbers of experimental points are in parentheses. Asterisks denote significant differences between groups (NS, non-significant; *, p < 0.05; **, p < 0.001). The differences in means in D and E were assessed by non-parametric Mann-Whitney U test.