Expression of zebrafish col10a1a and col10a1b and Xenopus Col10a1 during tooth development detected with in situ hybridization. (A, B) col10a1a expression in whole-mount zebrafish larvae at 4 and 6 days post fertilization (dpf). (C) col10a1a expression in post in situ paraffin sections of zebrafish larvae at 5 dpf. (D, E) col10a1b expression in whole-mount zebrafish larvae at 4 and 6 dpf. (F) col10a1b expression in post in situ paraffin sections of zebrafish larvae at 4 dpf. (G) HE staining of a longitudinal section through a developing tooth bud of a Xenopus larva at stage NF57. (H, I) Col10a1 expression in Xenopus tooth bud on successive transversal sections. Open arrowheads point at developing pharyngeal teeth and asterisk marks the mineralizing matrix. Scale bars: 100 µm (A, B, D, E), 50 µm (C, F), 20 µm (G, H, I). Abbreviations: amel., ameloblasts; cl, cleithrum; d, dentary; m, maxilla; od., odontoblasts; op, opercle; p, parasphenoid; sec. amel., secretory ameloblasts.