Fig. 3: Branched F-actin networks prevent the accumulation of myosin-induced mechanical tension.

a Actin overlay pre- (magenta, t = 0) and post-ablation (cyan, t = 150 s). yellow dashed lines show the ablation regions. b Actin velocity field quiver plot for post ablation (t = 150 s). c Absolute valued mean strain (\(|\left\langle {{{{{\rm{\varepsilon }}}}}}\right\rangle|\)) vs. time for post-ablation (t > 15 s) 83 nM mDia1 vs. 0.74 nM Arp 2/3-nucleated F-actin (left), and 830 nM mDia1 vs. 74 nM Arp 2/3-nucleated F-actin (right) (N = 10 independent experiments for each condition). Shaded regions indicate s.d. of the mean. d Maximum mean strain (\({\left\langle {{{{{\rm{\varepsilon }}}}}}\right\rangle }_{{\max }}\)) for actin post-ablation for 83 nM/830 nM mDia1-nucleated F-actin (red), and 0.74 nM/74 nM Arp 2/3-nucleated F-actin (blue). Bars with white stripes = ablation without Myosin II addition. (*p < 0.05, ***p < 0.001, and ns is not significant. p (74 nM Arp & 830 nM mDia1) = 0.0206, p(0.74 nM Arp & 83 nM mDia1) = 1.66e−5. N = 10 independent experiments for each condition. Error bars represent s.d. of the mean. Two tailed t test). e mDia1 viscoelastic response fit with Kelvin–Voigt model (Methods) (**p < 0.01. p = 0.0082. N = 10 independent experiments for each condition. Error bars represent s.d. of the mean. Two tailed t test. Source data are provided as a Source Data file).