Mubritinib and canertinib perturb CNC migration <i>ex vivo</i>.

<p>(A-C) Lateral views of tailbud stage <i>X</i>.<i>laevis</i> embryos after <i>in situ</i> hybridization with <i>Sox10</i> and <i>Twist</i> 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), 3<sup>rd</sup> and 4<sup>th</sup> 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 <i>ex vivo</i>. 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.</p>