Fig. 3: Enamel maturation dysregulation in Mast4 KO incisors.

a–h Enamel matrix protein (MMP20) and maturation-related protein (FAM83H) in the secretory and maturation regions of incisors from 6-week-old WT and Mast4 KO mice. The arrowheads indicate ameloblasts expressing MMP20 and FAM83H. The arrows indicate the expression of enamel matrix proteins. a, b In the secretory region, the expression of MMP20 was similar between the WT and Mast4 KO mice. c, d FAM83H expression was increased in Mast4 KO ameloblasts. e–h In the maturation region, MMP20 and FAM83H expression was decreased in ameloblasts as well as in the enamel matrix in Mast4 KO mice. i RNA-Seq analyses of apical buds and secretory ameloblasts from the incisors of 6-week-old WT and Mast4 KO mice. At the apical bud, the expression of Perp, Klk4, Enam (Enamelin), and Mmp20 was increased in Mast4 KO incisors. In the ameloblast region, the expression of Fam83h, Dlx3, and Wdr72 was increased in Mast4 KO incisors. D dentin, E enamel, Am ameloblast. Scale bar; 50 μm.