Fig. 7

Fig. 7 Hedgehog signalling is required from 72 hpf onwards for osteoblast differentiation in chondral ossification centres. (A, C, E and G) are control embryos treated with EtOH and (B, D, F and H) are cyclopamine treated embryos. Embryos treated from 48 to 72 hpf do not show any changes in colX expression at 144 hpf (A and B). However, those treated with cyclopamine from 72 to 96 hpf (C and D), 96 to 120 hpf (E and F) and 120 to 144 hpf (G and H) show reduced colX expression in chondral ossification centres. (I) shows the quantification of the number ceratohyal and hyomandibular primordia expressing colX at 144 hpf from (A–H) and at 96 hpf (Fig. 4G and H, marked by an asterisk). Please see Fig. 2 for abbreviations and notes.