Mitochondrial dynamics in differentiating fiber cells of the mammalian Lens

The distribution of mitochondria was investigated in living rat and monkey lenses using rhodamine 123 staining and confocal microscopy. In both species, epithelial cells contained abundant small mitochondria scattered throughout the cell volume. Mid-sagittal slices of the living monkey lens revealed that, at the lens equator, mitochondria were only present in fiber cells to a depth of approximately 100 μm. Mitochondria were not present in fiber cells that had already reached the suture line or fibers abutting the central epithelium. Dual-staining with rhodamine 123 and the vital nuclear stain thiazole orange revealed that the loss of nuclei and mitochondria was coincident during fiber cell differentiation.