Mubritinib and canertinib perturb CNC migration ex vivo.
(A-C) Lateral views of tailbud stage X.laevis embryos after in situ hybridization with Sox10 and Twist to visualize CNC positioning. Anterior is to the left, dorsal is up. Embryos treated with 40 μM of the ErbB2 inhibitor, mubritinib (N = 4, n = 72), or 25 μM of the pan-ErbB inhibitor, canertinib (N = 4, n = 68), show no difference in CNC migration compared to DMSO controls (N = 6, n = 100; N = 4, n = 69, respectively). (D-E) The distance of migration within each branchial arch was measured and normalized to the head size. CNC migration as observed in the mandibular (M), hyoid (H), 3rd and 4th branchial arches. (F-U) Time-lapse images of CNC explants migrating on fibronectin substrate and treated with 0.5% DMSO (N = 8, n = 24), 6 μM mubritinib (N = 4, n = 12), 10 μM canertinib (N = 4, n = 12), and 20 μM LY294002 (N = 3, n = 9) for indicated lengths of time. (V) Fold change in explant surface area over time. Areas were normalized to measurements calculated at initial time points (t = 0). All inhibitors significantly decreased CNC migration ex vivo. Error bars represent the 95% confidence interval. One-tailed, Student’s t-tests were performed to determine statistical significance. ** p<0.01, ***p<0.001. N, number of experiments; n, number of embryos or explants.