FIGURE 2.

Absence of LDs in the hearts of Plin5^−/− mice. A, ORO staining of heart cryosections of wild-type (panels a, b, e, and f) and Plin5^−/− (panels c, d, g, and h) mice in the fed (panels a–d) and fasted (panels e–h) states. Panels a, c, e, and g, low magnification (bar, 25 μm). Panels b, d, f, and h, high magnification (bar, 10 μm). No LD was observed even by close inspection of the sections of Plin5^−/− mice in either state. In wild-type mice, out of 20 randomly selected microscopic fields (each 86.4 × 60.5 μm), four in the fed state and all in the fasted state contained detectable LDs. The number of LDs in a field was 18.7 ± 11.0 in the fed mice and 966 ± 409 in the fasted mice, respectively (p = 4.3 × 10⁻⁹). The sizes of LDs were 0.22 ± 0.04 μm in the fed and 0.64 ± 0.11 μm in the fasted states, respectively (p = 2.3 × 10⁻⁷). B, representative electron microscopic images of the hearts of wild-type and Plin5^−/− mice fasted overnight. Left panels, low magnification (bar, 10 μm), and right panels, high magnification (bar, 2 μm). Note that LDs are observed as white ovals only in wild-type mice. C, ORO staining of soleus muscle cryosections. Panels a and b, wild-type, and panels c and d, Plin5^−/− mice, both fasted overnight. Panels a and c, low magnification. Bar, 100 μm. Panels b and d, high magnification of the area enclosed by a rectangle. Bar, 25 μm.