Figure 5. LSCM micrographs of myosin IIA and actin immuno-fluorescence at posterior fiber ends. A-B: Paired fluorescent (A) and DIC (B) images of myosin IIA labeling in the peri-sutural region. Myosin was localized as a diffuse plaque in the BMC (arrowheads) and was also present filling the cytoplasm of posterior fiber segments. A and B are at identical magnification. C-F: The same field of view showing myosin IIA fluorescence (C), the DIC image (D), actin fluorescence (E) and the merged myosin-actin fluorescence (F) at a suture branch. Basal fiber ends at the suture (D, arrow), were delineated by actin (E and F, red profiles) and were filled with myosin (C and F, green plaques). Asterisks (C and D) indicate an area devoid of both labels, which was due to an artifactual break in the vibratome section. C through F are at identical magnification. The data revealed that myosin IIA distribution in the BMC was consistent in the sutural, peri-sutural, and lateral-posterior regions of fiber end migration.