Fig. 8

Attachment of filopodia to RGD-coated rigid and fluid substrate. a HeLa-JW cells expressing GFP-myosin X were plated on micropatterned coverslips covered with circular islands (D = 3 μm) of SLB conjugated to RGD (orange circles), organized into a square lattice. The glass between the islands was covered with poly-l-lysine-PEG (PLL-PEG) conjugated to RGD at the same density (Supplementary Fig. 6). Trajectories of GFP-positive filopodia tips acquired during a 14–36 min time interval are shown. The cell border is shown by a yellow dashed line. For comparison of the trajectories on rigid and fluid substrates, the circles of similar diameter were drawn by computer in the centers of the square lattice formed by SLB islands (outlined by gray contours). The segments of the trajectories located inside either the SLB islands or the drawn circles on the rigid substrate are shown in red, and the remaining parts of the trajectories are shown in white. See also Supplementary Movie 25. Scale bar, 5 μm. b Dwelling time that myosin X-positive filopodia tips spent inside fluid (orange) or rigid (green) circles defined above. Pooled data for 5 cells; n—number of filopodia tip trajectories analyzed. Aligned dot plots and mean ± s.e.m. values are shown. The p value was calculated using unpaired two-tailed t test with Welch’s correction