Fig. 5

Fig. 5

Successional dental epithelium (SDE) expression in zebrafish and stickleback. In all panels, a dotted line demarcates the basalmost pharyngeal epithelial layer, which is made gray when missing from a particular section (e.g., when it is interrupted by an erupted tooth). a Expression of bmp6, bmpr1aa, cd34, gli1, igfbp5a, nfatc1, lgr4, lgr6, pitx2 was assayed by in situ hybridization (ISH) in zebrafish. Expression of all 9 genes was detected in the successional dental lamina (SDL—black arrowheads). b Expression of Bmp6, Bmpr1a, CD34, Gli1, Igfbp5a, Lgr4, Lgr6, Nfatc1b, and Pitx2 was assayed by ISH in stickleback. Expression of all nine genes was detected in the proposed “successional dental epithelium” (SDE) of stickleback. Black arrowheads mark the SDE. Bmpr1a and Gli1 were additionally expressed in the superficial oral epithelium surrounding erupted teeth (white arrowheads). Tooth germs are indicated with a black arrow. All scale bars = 20 μm