Fig. 4
(A) Schematic diagram showing the teeth located on the fifth gill arch in zebrafish. (B) Schematic diagram showing five pairs of toothless pharyngeal arches in the common seadragon. (C to J) Comparison of number and distribution of pharyngeal teeth in mutant (scpp5−/−; G, H, and I) versus wild-type (scpp5+/+) fish (C, D, and E). Eleven of 24 (45.8%) F3 homozygous scpp5−/− individuals exhibit a marked reduction in the number of teeth related to a failure of tooth replacement (G, H, and I, black arrowheads). (F and J) Schematic representations of the tooth phenotype of scpp5+/+ and scpp5−/− fish, respectively (ventral tooth row, blue; medio-dorsal tooth row, orange; dorsal tooth row, green; and the dotted lines indicate missing tooth structures). Scale bars, 0.5 mm; a, anterior; p, posterior.