Fig 3

Bone elements are reduced in polr3a^sa907/sa907 zebrafish.
(A,B) Images of the opercle at 4 dpf expressing sp7:gfp (osteoblasts) and stained with Alizarin red (bone, magenta) show that both the osteoblasts (E; *p = 0.01) and bone (F; ****p < 0.0001) are significantly reduced in mutants. n = 14 controls, 6 mutants. (C,D) Images of the opercle at 6 dpf show that it is significantly reduced in size and that osteoblasts (G; ***p = 0.0003) and bone (H; ****p < 0.0001) remain significantly reduced in mutants. n = 11 controls, 13 mutants. (I,J) Ventral views of control and polr3a^sa907/sa907 zebrafish reveals hypoplasia of multiple cranial bones including the maxilla (mx), dentary (de) and branchiostegal rays (bsr). (K,L) Quantification of sp7:gfp and Alizarin red within the dentary. The dentary is shorter and wider in polr3a^sa907/sa907 zebrafish, but no significant changes were observed in the overall volume (K; ns, p = 0.28) while Alizarin red is significantly reduced (L; *p = 0.01). (M,N) Quantification of sp7:gfp and Alizarin red within the maxilla. The maxilla is smaller in size overall with reductions in both sp7:gfp (M; ****p < 0.0001) and Alizarin red (N; ****p < 0.0001). n = 11 controls, n = 10 mutants. Scale bar = 100 µm.