Figure 7.

Actin filament orientation in blebbistatin-induced bundles. Cells were treated with 100 μM blebbistatin for 60 min, then permeabilized, decorated with HMM, fixed, negative stained, and viewed as whole mounts. This electron micrograph shows a slightly splayed region of a microfilament bundle located ∼3 μm proximal to the cell's advancing edge, which was to the left of the photographed region. White arrows indicate the orientation of HMM arrowheads on the individual filaments. All of the filaments are oriented with their plus (+, barbed) ends toward the leading edge of the cell.