Extended Data Fig. 6: hEGF increases cell contractility and surface tension.

a, Time lapse evolution of the modulus of the traction forces upon addition of 10 ng ml⁻¹ of hEGF and the subsequent addition of 5 µg ml⁻¹ of Y27632 (indicated by vertical dashed lines). Gel stiffness is 6 kPa. b, Cluster area variation during the protocol described in (a). Data in panels a-b are median ± 95% CI estimated by bootstrapping (n = 15 clusters). c-f, In-plane traction forces exerted by a representative cluster before addition of hEGF (c), 1.5 min after the addition of hEGF (d), 3 min after the addition of hEGF (e), and 42 min after the addition of Y27632 (f). g, The normal traction component \(T_z\) increases 2 min after adding hEGF, indicating an increase in surface tension and Laplace pressure. A paired permutation test (two-tailed) indicated a significant increase (n = 13 clusters, P value= 0.0002441). h-i, \(T_z\) maps exerted by a representative cluster before (h) and after (i) the addition of hEGF. Scale bar is 50 µm.