(a) Model of pk1b and vangl2 sgRNA target sites. Underlined sequence denotes the NGG motif used by Cas9. (b) Images are 20-µm dorsal-view projections of the hindbrain at 2 dpf. Anterior is up. Scale bar, 20 µm. Larvae are transgenic for Tg(isl1:GFP)rw0, which marks the branchiomotor neurons. A subset of these, the facial branchiomotor neurons (shown), undergo a stereotypical migration from rhombomere 4 (r4) to r6. Mutants in the planar cell polarity pathway (pk1b and vangl2) cause a failure in this migration. These phenotypes can be recapitulated in injected CRISPR F0 embryos. (c) Quantitation of migration defects. (d) Lateral views of 1-dpf embryos. Scale bar, 1 mm. vangl2 mutants have defects in anterior-posterior axis elongation due to defects in mesodermal convergence and extension. This can be recapitulated in injected CRISPR F0 embryos. (e) Quantitation of convergent extension defect. In c and e, N > 24 embryos for each bar.