Fig. 3. Actin filaments in melanophores. Actin filaments were identified by decoration with the S1 subfragment of myosin and platinum replica electron microscopy. (a) Control cell. High magnification view (of boxed region in (b)) showing characteristic asymmetric Œrope-like' appearance of decorated actin filaments. Thicker end of individual rope elements points toward the pointed end. (b) Control cell. Low magnification view showing distribution of actin filaments, colorized yellow. Actin filaments frequently contact pigment granules and show no preferential orientation. (c) Latrunculin-treated cell. Virtually no actin filaments (colorized yellow) remained. Bars, 1 µm.