FIGURE 7.

Desmin plays a role in nuclear localization in varying fiber types. Single fibers were prepared from the plantaris (PL) and soleus (SOL) muscles of 5-week-old control (+/+) and desmin-null (−/−) mice. They were stained with Hoechst 33342 to label the nuclei and observed under ultraviolet fluorescence. In +/+ fibers, nuclei are regularly distributed and often oriented longitudinally. In −/− fibers, their distribution is less regular and transverse orientation is frequent. Clusters of nuclei (arrowheads) are occasional in the plantaris but frequent in the soleus. The soleus −/− panel shows two fibers (arrows), one of which presents a normal-looking segment in this field. Bar, 20 μm.