Fig. 3

PSC-derived SG placodes formed invaginating epithelium and initial buds developing lumen-like structures. A–C PSC-derived SG placodes formed invaginating epithelium and initial bud-like structures from D6 to D10, which expressed a high level of Sox9 and E-Cadherin. Scale bars: 100 μm (A–C) and 50 μm (A’–C’, magnified images, marked by dotted boxes). D Immunofluorescence staining of E11.5 and E12.5 mouse submandibular glands. Green: E-Cadherin (Epithelium marker), red: sox9 (early-stage progenitor marker), blue: DAPI (nucleus). Scale bars: 50 μm. E–F The expression pattern of Krt5 and Krt19 in duct-like structures of SG placodes suggested polarized differentiation of lumen (a, marked by arrow), which was not observed in the invaginating epithelium (F) Scale bars: 100 μm (E, F) and 50 μm (E’, F’, magnified images, marked by boxes). G Immunofluorescence staining of E12.5 and E14.5 mouse submandibular glands. Green: Krt5 (salivary gland progenitor marker), red: Krt19 (lumen progenitor marker), blue: DAPI (nucleus). Scale bars: 50 μm (E12.5) and 100 μm (E14.5)