Fig. 1: Endogenous electric fields modulate neural crest dCCM.
From: Stretch-induced endogenous electric fields drive directed collective cell migration in vivo
a, Scheme of an X. laevis embryo at pre-migratory stages (left) and cross-sectional cartoon showing the vibrating probe measurements (right). Pos, position; A, anterior; P, posterior; M, middle; L, lateral; D, dorsal; V, ventral. b, Vibrating probe current density measurements. The solid lines represent the mean and the shade, the standard errors. Reference was set as >1 mm away from the embryo. Two-tailed Mann–Whitney U-test, ****P < 0.0001, n = 7 embryos. The calculated electric field (EF) is shown in the inset. c, Schematic showing glass microelectrodes impaling positions in the subectodermal space beneath the neural fold and flank ectoderm. The reference electrode is >1 mm away from the embryo. d, TEP measurements. The solid lines represent the mean and the shade, the standard errors. Two-tailed paired t-test, ***P = 0.0001, n = 11 embryos. The calculated EF is shown in the inset. e, Schematic showing the endogenous EFs in the migratory path of the neural crest as observed from current densities and TEP measurements. f–i, Ex vivo electrotaxis assay. Time-colour-coded trajectories of neural crests migrating in the absence of EFs (f), under EFs (100 mV mm−1) (g) and after EF reversal (h), 4 h in each case. The arrows indicate the direction of migration. Scale bar, 100 μm. i, FMI. The red lines represent the mean and the error bars, the standard deviation. Two-tailed t-test for no EF versus EF, two-tailed Mann–Whitney U-test for no EF versus EF reversal, ****P < 0.0001, nNo EF = 27, nEF = 33 clusters. j–m, Application of exogenous EFs (100 mV mm−1) in vivo, with treatments as indicated. j,l, Lateral views of embryos hybridized against neural crest markers c3 (j) and sox8 (l). Scale bar, 200 μm. k,m, Normalized stream displacement. The red lines represent the mean and the error bars, the standard deviation. k, Two-tailed t-test, ****P < 0.0001, nNo EF = 36, nAntiparallel EF = 31 embryos. m, Two-tailed t-test with Welch’s correction, *P = 0.0110, nNo EF = 42, nParallel EF = 39 embryos. f–h,j,l, Representative examples from three independent experiments; CI = 95%.
