Fig. 1

Distribution and expression of PRX1 in molar tooth germs. a Prx1 expression in integrated molar germs from four stages via UMAP. Epithelial and mesenchymal lineages were separated by classic markers respectively, including Msx1, Gli1 for mesenchyme and Krt14, Krt5 for Epithelium. epi epithelium, mes mesenchyme. b Correlation between PRX1-positive cells and dental mesenchyme or epithelium at from bud stage to secretory stage. The PRX1-positive cells distributed mostly in the condensed mesenchyme of developing molar, especially at the early morphogenetic bud through the cap stages. epi epithelium, mes mesenchyme. c Distribution of PRX1-positive cells in M1-M3 of the maxillary and mandible at P7.5 (n = 3). The triangles indicate areas of mesenchymal origin. The dotted line marks the edge of tooth germ and the boundary between epithelium and mesenchyme. PRX1⁺ cells and their progeny (red) were confined to the pulp of M1 and M2, but were rarely distributed in M3. M1 the first molar, M2 the second molar, M3 the third molar, od odontoblast, am ameloblast, dp dental pulp. Scale bar: 100 μm