Movements of melanosomes along actin in an RPE cell. Cultured WT primary mouse RPE cells transfected with F-tractin-GFP. Single z-plane images were collected by a spinning disk confocal microscope at 2 frames per sec for 3 minutes. The playback rate of the movie is 20 frames per second (i.e. 10x real speed). Scale = 3 μm.