Fig. 9 Myosin spots are stationary in the lamellipodia of a locomoting keratocyte (a), but exhibit retrograde flow in the lamellipodia of a tethered cell (b). General views of TMR-myosin-injected cells and time-lapse sequences for boxed areas are shown with time indicated in minutes and seconds. Dotted lines indicate fixed positions with respect to the substratum. Selected myosin spots are shown with arrows. In (a) the marked myosin spot is stationary while in the lamellipodia, but exhibits forward displacement at 50 s when it reaches the cell body. Bars, 2 µm.