Figure 3. PTPMT1 maintains mitochondrial membrane integrity.
A) Ptpmt1-deficient MEFs have fragmented mitochondria. Two weeks after deletion of Ptpmt1, cells were stained with anti-cytochrome c antibody and visualized by immunofluorescence microscopy. DNA was stained blue with 4′,6-diamidino-2-phenylindole (DAPI). B) Electron micrographs of Flox MEFs. Normal mitochondria with lamellar cristae are enlarged in the inset. Scale bar, 1μm. C) EM images of defective mitochondria in KO cells. Inset shows a vesicular mitochondrion and rupture of the outer mitochondrial membrane/OMM (red arrow). Red asterisk, loss of cristae and matrix components. D) Morphometric analysis of mitochondrial length. Mean ± SEM, n=80. E) Morphometric analysis of cristae/OMM surface area ratio. Mean ± SEM, n=52. ***p<0.001, **p<0.01.