Fig. 6. Polymerization and alignment of microtubule plus-ends at target sites. B16F1 cells were co-transfected with GFP-CLIP170 to track polymerization of microtubule plus-ends (green) and mRFP-actin (red) to visualize filopodia. A polymerizing microtubule end (arrowhead) approaches a filopodium base and then aligns with the filopodium at 00:15 seconds. Bars, 2 µm.