Fig. 4

Fig. 4 MO knockdown: jaw cartilage. (A) Slight reduction in dlx2 staining at 18 hpf (lateral view). (B) Reduction in dlx2 is prominent in posterior arches at 27 hpf. (C) Reduction in gsc staining at 48 hpf, ventral view. (D) Reduced cartilage elements in 4 dpf larvae revealed by Alcian blue staining, ventral view. Plainly visible jaw defects were observed in 36% of Alcian blue-stained embryos (n = 14) injected with MO at 1 mg/ml, and 82% of embryos (n = 28) injected at 2 mg/ml, compared with 0% (n = 19) injected with buffer alone. m, Meckel′s cartilage; pq, palatoquadrate; ch, ceratohyal; cb, ceratobranchial; bb, basibranchial. (E) Ceratobranchial elements are significantly reduced after morpholino injection (n = 30) when compared to mismatch control (P = 0.002). A slight but consistent reduction is also seen after mismatch morpholino (n = 26) compared to uninjected controls (n = 22).