Figure 3
Ultrastructural analysis of Dct-expressing cardiac cells.
(A) Low-power and (B) high-power transmission electron microscopy demonstrated association between 4 Dct-LacZ–expressing cells. White arrowheads indicate electron-dense X-gal precipitate in the cytoplasm and perinuclear area. N denotes the same nucleus in both A and B (scale bars: 2 μm and 1 μm, respectively). (C and D) High-power transmission electron microscopy of 2 Dct-expressing cells. Cells in C contained no melanosomes, while Cell2 in D contained type III and type IV melanosomes. Cell1 contained X-gal precipitate (white arrowhead). Black arrowheads in C and D denote caveolae. Scale bars: 500 nm. (E and F) High-power transmission electron microscopy of mitochondria in the atrial myocardium of a Dct+/– mouse (E) and a Dct–/– mouse (F). Note that some mitochondria appear slightly enlarged, with less densely packed and disorganized matrices in the absence of Dct. Scale bars: 500 nm. N, nucleus; M, mitochondria; III, type 3 melanosome; IV, type 4 melanosome.
