p150-SA8-GFP displays higher affinity for microtubules than wild-type p150-GFP protein during mitosis. S2 cells expressing equivalent levels of p150-GFP (left) or p150-SA8-GFP (right) were imaged by time-lapse video microscopy (Videos 1 and 2). The p150-SA8-GFP protein is strongly associated with spindle fibers and microtubule plus ends, whereas p150-GFP shows moderate association with these structures (arrowheads). The kinetochore localization (arrows) is not affected. Bar, 10 µM.