Fig. 4

FBMN length-width ratio (LWR) is altered in Pk1b morphants. A-D: Dorsal views of fixed embryos highlighting differences in cell shape and orientation along migratory path. A: Control, 18 hpf. B: Pk1b morphant, 18 hpf. C: Control, 24 hpf. D: Pk1b morphant, 24 hpf. Flattened confocal z-stacks. Scale bars = 20 μm. Dashed lines represent rhombomere boundaries, which were assessed by EphA4 immunostaining. E: Schematic explaining LWR measurement. A bisecting line was drawn through the longest axis of each neuron, and another bisecting line was drawn perpendicular to the first. The line that most closely aligned with the A-P axis was defined as the width, while the perpendicular line was defined as the length. If the value of LWR ≈ 1, we considered these cells to be "round". F: Bar graphs summarizing average LWR in each rhombomere at both early and later stages of migration, in control and Pk1b morphant embryos. *P < 0.05; **P < 0.01; ***P < 0.001.