Fig. 2.
Mouse lower incisor shape and length are regulated by Sox2. (A) 3D reconstructions from micro-CT scans showing the dental epithelium in dark grey. The internal layer of the dental epithelium (b-d,f-h) or vestibular lamina (a,e) appears in light grey. Sox2cKO incisors exhibit an aberrant morphology at all embryonic stages. At E13.5, the tooth domain is broader, and at E15.5 clefts (red arrowhead) appear. The defects can vary within the same individual (g). (B) Histological staining of frontal sections shows that the well-organised ameloblast layer seen in control incisor (green arrowhead) is not visible in Sox2cKO individuals. A cleft is visible on the labial side of the mutant incisor (red arrowhead). (C) The length of the epithelial compartment is similar in the control and Sox2cKO at E15.5. The incisor length increases over 2 mm from E15.5 to E18.5 in controls, but only 0.6 mm in mutants. E17.5, *P=0.016; E18.5, *P=1×10−5; n.s., not significant. n=3. Scale bars: A, 50 µm; B, 100 µm.