Lingual incisors in K5-Ikkβ mice. (A–C,
J) Sagittal sections showing labial cervical loop in
endogenous incisor (arrows in A, B) and lingual incisor (arrows in C, J) of
wild-type (A), K5-Ikkβ mice (B, C),
and Wise mutant (J) at P5. Arrowheads indicating
ameloblasts (A, B) and the lack of ameloblasts (C). (D)
Sagittal sections showing Amelogenin mRNA expression in
K5-Ikkβ mice. Arrowhead indicating lingual incisor (D).
(E–G) Endogenous and lingual incisors before clipping (E),
just after clipping (arrow in F), and at 2 wk after clipping (G). Arrow
indicating newly formed lingual incisor (G). (H, I) Frontal
section based on micro–computed tomography scan in lower incisors of
wild-type (H) and Wise mutant (I). Arrow indicates lingual
incisor (I). (K, L) Wise
expression by radioactive in situ hybridization on frontal sections of
wild-type (K) and K5-Ikkβ mice (L) at E15.5. Arrowheads
showing Wise expression on the lingual side of endogenous
incisor tooth germs (L). The labial cervical loop was outlined by blue dots
(C, J). Scale bars: 500 µm (A, B, H, I), 300 µm (C), 150 µm (D, J), and 200
µm (K, L).