Figure 4.

Schematics of the mandibular and hyoid regions of a mouse embryo at E12, superior view at the nascent tongue from inside of the alimentary canal. Bmp4 and Edn1 are expressed in the distal mandibular epithelium, while Bmp4 also marks the site of presumptive incisors. Shh is expressed in lingual epithelium of the tongue primordium. Fgf8 is expressed in the proximal mandibular epithelium, at the site of presumptive molars, while Barx1 is expressed in the proximal mandibular ectomesenchyme, surrounding the molar primordia, and in ectomesenchyme of the hyoid arch. Dlx5/Dlx6 are expressed in ectomesenchyme of the mandibular process and the hyoid arch. Lhx6/Lhx8 are expressed in the ectomesenchyme on the rostral side, while Gsc is expressed on the caudal side of the mandibular process. Abbreviations: E, embryonic day; T, tongue primordium; HE, hypobranchial eminence (second PA); FC, foramen caecum. Expression domains of genes written in black text are not highlighted in the figure.