Fig. 1

kif5Bs contribute to craniofacial development.

A) Using Crispr-CAS9 mutagenesis to target the N-terminus, ae21 (9bp deletion), ae22 (4bp deletion), ae23 (5bp deletion) and ae24 (2bp insertion causing a frame shift and early stop codon) kif5Bb mutant alleles were generated. Exon is indicated in yellow, PAM region in orange, red dash or blue areas indicate mutated regions. B) qRT-PCR for kif5Ba and kif5Bb in kif5Ba^ae12/ae12 and kif5Bb^ae24/ae24 embryos. kif5Bb transcripts undergo NMD in kif5Bb^ae24/ae24 mutants. One-way ANOVA * p<0.05. C-E) Live images of 6dpf kif5Bs mutants. Mutation of kif5Ba causes incompletely penetrant jaw protrusion defects (arrow in D and D´). kif5Ba^ae12/ae12Kif5Bb^ae24/ae24 mutants exhibit a fully penetrant phenotype, including flat heads (arrows in E and E´). F) Measurements of the jaw protrusion in each genotype. One-way ANOVA ** p<0.01, *** p<0.001, **** p<0.0001. G-J) Whole-mount in situ hybridization of sox9a (G, H) and col2a1 (I, J) revealed no differences between Wt and mutants. Arrows indicate the cartilage region. K-N) Alcian blue staining at 3 dpf, arrow indicates inset region. Intact cartilage elements in kif5blof are shorter and mediolaterally broader, the angle at the ceratohyal cartilage intersection is wider (arrowheads in K, N). Alcian blue stain reveals defective chondrocyte stacking (insets in K-N). O-R) Alcian blue staining at 5 dpf, arrow indicates the inset region. Meckel´s cartilage has extended anteriorly (O) in Wt but not in kif5Blof mutants. (P-R) the Meckel´s and ceratohyal cartilages are curved in kif5Blof (arrowheads in O-R), Alcian blue staining is diffuse, and cell stacking is absent (insets in P-R). ch: ceratohyal; m: Meckel´s; pq: palatoquadrate. Scale bars: A-H: 500μm; I-P: 50μm.