Types of cytoskeletal filament arrays. Type A: simple filament arrays that can self-assemble in the absence of spatially regulated nucleators or molecular motor protiens. Shading indicates the orientation of filament polarity. Type B: complex filament arrays that require either nucleation or motor protein activity, or both. Dark circles represent nucleators.
Theriot BMC Biology 2013 11:119 doi:10.1186/1741-7007-11-119