Fig. 2

eve1 expression in differentiating ameloblasts of first generation (3V¹ and 5V¹) and replacement (4V², 3V² and 5V²) teeth. A-E: At 80 hours postfertilization (hpf). A: Transcription of eve1 in teeth 3V¹ and 5V¹. Top: ISH eve1, whole-mount, lateral view. Bottom: Interpretative drawing. While the transcription has ceased in tooth 4V¹, two new bilateral eve1-expressing cell clusters appear that correspond to the forming teeth 3V¹ and 5V¹ (arrows). B-E: Transverse sections through the pharyngeal region at the level of the Vth branchial arch. Left panels: In situ hybridization (ISH) eve1; middle panels: camera lucida drawing of the mirror image of the section; right panels: control, nonhybridised specimen. Early differentiation stage of teeth 3V1 (B, C), 5V1 (D,E). The arrows point to tooth 4V¹, in which dental matrix has accumulated. C,E: the arrowheads indicate the location of teeth 3V¹ and 5V¹, respectively. F,G: At 120 hpf. Early differentiation stage of replacement tooth 4V². Left panel: ISH eve1; right panel: control, nonhybridised specimen. In G, the black arrows point to teeth 3V¹, the white arrowheads to teeth 5V1, and the white arrows to tooth 4V². H,I: At 168 hpf. Early differentiation stage of replacement teeth 3V² and 5V², respectively. Left panels: ISH eve1; right panels: camera lucida drawings of the mirror image of the section. pf, pectoral fin; other abbreviations as in Figure 1A. Scale bars = 100 μm in A, 50 μm in B-I.