Figure 2

Figure 2. Expression of secretory calcium-binding phosphoprotein 5 (scpp5) during zebrafish tooth development. Transverse sections of zebrafish postembryonic stages (72–120hpf – A–E) and adults (F–J) in the region of the pharyngeal jaws, with explanatory schemes for postembryonic stages. At 72hpf (A) the initiator tooth (4V¹) at LC stage expresses scpp5 in both ameloblasts and odontoblasts, whereas no expression is detected for the first-generation teeth 3V¹ and 5V¹, still at EC stage. Between 80 (B) and 96hpf (C) tooth 4V¹, now attached, shows no expression of scpp5, while 3V¹ and 5V¹ at LC stages start to express scpp5 in both ameloblasts and odontoblasts. Between 96 (D) and 120hpf (E) the second-generation teeth (4V², 3V², and 5V²) fail to express scpp5 during EC but upregulate expression in both ameloblasts and odontoblasts at LC. During the development of adult teeth, the expression of scpp5 is detected in both ameloblasts and odontoblasts at EC (F), LC (G) and when the tooth starts to attach to bone (H). Expression is restricted to odontoblasts when the tooth is completely attached [(I) and (J)]. Tooth developmental stages: A, phase of attachment; EC, early cytodifferentiation; LC, late cytodifferentiation. Br, brain; cl, cervical loop; Nt, notochord; sb, supporting bone; Y, yolk; asterisks, “bone of attachment”; arrows, cells forming “bone of attachment”; white arrowheads, ameloblasts; black arrowheads, odontoblasts. Scale bar (A-E)=10μm, (F–G)=50μm, (H–J)=100μm.