Superiority of focused ion beam-scanning electron microscope tomography of cardiomyocytes over standard 2D analyses highlighted by unmasking mitochondrial heterogeneity.

Here, we demonstrate the need of 3D analyses for the characterization of mitochondrial features in cardiac tissue samples. Hence, we observed that BNIP3 deletion physiologically acts as a molecular brake on mitochondrial number, suggesting a role in mitochondrial fusion/fission processes and thereby regulating the homeostasis of cardiac bioenergetics.