Figure 2. Migration is controlled by the matrix stiffness.

(A) Superimposed migration trajectories of individual keratocytes plated for 30 min on flat substrates with various rigidities (red: 1.5 kPa, blue: 9 kPa, green: 110 kPa, orange: 3 MPa and purple: 70 GPa) and similar FN coatings. Initial positions of the crawling cells were superimposed at the origin for comparison. All plots range from −350 μm to + 350 μm on both the x- and y- axis. (B) Evolution of migration curvature as a function of the matrix stiffness. 85 ≤ n ≤ 160 for each population. (C) Evolution of the lamellipodial curvature as a function of the migration curvature. (D) Variation of the motility coefficient, μ, as a function of the substrate stiffness. The green mark represents the range of Young’s moduli of the internal side of fish scales³⁷. Data are shown as mean ± s.d.