Figure 3.

A Pool of β-Actin Resides in Mitochondria, Without Which TFAM-Stained Nucleoids Tend to Form Large Aggregates

WT and KO MEFs were stained with MitoTracker Deep Red (red) and a β-actin-specific antibody (green) or anti-TFAM antibody (green) and visualized by STED microscope.

(A) Comparison of β-actin staining and its distribution between WT and KO cells. Scale bar, 5  μm.

(B and C) STED microscope image insets selected from WT cell (B) and KO cell (C). Gray lines represents the boundary of mitochondria in the β-actin insets; scale bar, 1  μm.

(D) Montage of six consecutive z stack confocal images in WT cells, moving 250 nm in each step. Scale bar, 2  μm.

(E) STED microscope image of MitoTracker Deep Red (red) and anti-TFAM antibody (green) staining in WT and KO cells; scale bar, 5  μm. Arrows point to examples of enlarged mitochondria.

(F and G) STED microscope image insets selected from WT cell (F) and KO cell (G); scale bar, 1  μm; arrowheads in (G) indicate TFAM-based nucleoid aggregates.

See also Figures S3 and S4.