Fig. 6 Organization of myosin II filaments in keratocytes. Electron microscopy of detergent extracted and gelsolin-treated cells with (a-d) or without (e-g) myosin immunogold labeling. (a), overview of a cell; (b, c), clusters of gold-labeled myosin filaments; (d) gold-labeled myosin filament network (upper right) that gradually transforms into boundary bundle (lower left); (e) part of a cell without labeling; (f) individual myosin bipolar filament; (g), cluster of myosin bipolar filaments associated predominantly at their heads. The cell's leading edge is oriented upward in all panels. Left, middle and right boxed regions in (a) are enlarged in (b), (c) and (d) respectively. Small and large boxed regions in (e) are enlarged in (f) and (g) respectively. Bars, 1 µm.