Fig. 3

Analysis of the dynamics of neural crest migration in ct110a embryos. (A–F) Confocal projections of time-lapse imaging of live Gt(foxd3-citrine)^ct110a embryos. Dorsal views. Panels represent 1 h intervals. FoxD3-Citrine signal is depicted in green; membrane-tagged mCherry, red; H2B-Cerulean, blue. (A) Onset of FoxD3-Citrine expression at the 1–2 somite stage as NCCs are induced in the anterior neural plate border. (B) Expansion of FoxD3-Citrine expression along the neural plate border. (C) Segmentation of the neural crest field is first delineated by the appearance of furrows (asterisks) along its rostral-caudal extent. (D) A subset of NC cells moves towards the midline (arrowheads) at specific anterior-posterior levels. (E) Citrine-positive cells return from the midline to the lateral aspect of the neural tube, migrate towards the head and branchial arches, where they will condense. (F) Consolidation of the rostral-caudal segmentation of cranial neural crest as they migrate anteriorly to the head region, or condense in pre- and post-otic ganglia. Scale bars, 100 μm. (G–J) Cell tracking analysis of time-lapse dataset. Dorsal views. (G) Panel represents projection of a single time-point. (H and I) Co-localization of Citrine signal with H2B-Cerulean is depicted in white. (J) Tracing of NC migration obtained by tracking co-localization signal in a representative time-lapse dataset of Gt(foxd3-citrine)^ct110a embryos. (K–P) Phases of the morphogenetic movements of cranial NCCs in zebrafish. (K–N) Projection of NC displacement trajectories analyzed for each phase. Dorsal views. Thin arrows represent the displacement vectors of NC cells. Thick arrows are the projection of the resultant displacement unit vector, color-coded for each corresponding region. Resultant magnitude values are normalized for the number of trajectories and indicated in micrometers. Scale bars 50 μm. (K) Induction of NCCs in the neural plate border and initial migration to the midline. (L) Migration of NC to the midline and anteriorly. (M) NCCs migrate laterally and anteriorly towards the branchial arches and head. (N) Consolidation of NCCs position in branchial arches and head region for subsequent differentiation. (O) Quantitative analysis (mean±s.e.m.) showed that on average, displacement of cranial NC cells is significantly distinct during Phases I, II and III/IV. Difference in displacement length between phases III and IV is not significant. ANOVA statistical test P<0.0001. (P) Quantitative analysis showed that NC migrate faster during Phase II, and slow down as cells migrate to their final destination for subsequent differentiation. Speed is significantly different among Phases I through IV. ANOVA test P<0.0001.