Extended Data Fig. 3: Ex vivo electrotactic setup, impact in polarity and response of neural crest clusters versus single cells.
From: Stretch-induced endogenous electric fields drive directed collective cell migration in vivo
Exploded view drawings of the design and assembly steps of the electrotactic chamber used ex vivo (a) and for the electric chamber used for in vivo experiments (b). Order of assembly is bottom-up, except for the agar bridges that close the circuit just prior to EF application. Further details in Methods. Charge flows from anode (+ pole) to cathode (− pole). Scale bar, 10 mm. (c) and (d) device controls. (c) Temperature and (d) pH controls when applying a 100 mV mm−1 electrical stimulus for 4 h. Central tendencies are median and errors interquartile ranges. c, Kruskal-Wallis’ test, n = 4 each case; d, Two-tailed Wilcoxon matched-pairs test, n = 4. 4 independent experiments. e, Immunofluorescence against activated Rac1 during electrotaxis, 1 h of exposure to EF in each case. Arrows indicate the direction of migration. Scale bar, 30 μm. f, Time color-coded trajectories of clusters and isolated neural crest cells migrating in electric fields of 100 mV mm−1. White arrows depict clusters trajectories. Note that single cell representative panel has been zoomed in to visualize the single cell. Scale bars, 100 μm. g, Rose plots showing the angle frequencies of migration in relation to the electric field vector (anode and cathode are indicated). h, Forward migration index (FMI). Red lines represent mean and error bars standard deviation. Two-tailed t-test with Welch’s correction, ****p < 0.0001, nClusters = 18, nSingle cells = 43. e,f, Representative examples from three independent experiments; CI = 95%.
