Msx2-creER+ early mesenchymal cells exhibit broader
differentiation potential than Osx-creER+ osteoblast
precursors. (A–A′′) Sagittal sections of Msx2-creER;
R26RTomato mandibles at P0 (tamoxifen at E10.5) stained for
Sox9, osteopontin (OPN), and nuclei. A′: Meckel’s cartilage; A′′: mandibular body. DP,
dental pulp; M1, mandibular first molar; M2, mandibular second molar; Me, Meckel’s
cartilage. Light blue: OPN–Alexa 647; green: Sox9–Alexa 488; red: tdTomato; gray:
4′,6-diamidino-2-phenylindole (DAPI) and differential interference contrast (DIC).
Scale bars: 500 µm (A) and 50 µm (A′–A′′). (B) Sagittal sections of
Msx2-creER; R26RTomato posterior cranial vault at P0
(tamoxifen at E10.5) stained for Sox9, OPN, and nuclei. Inset: magnified view of the
transitional area. UC, underlying cartilage. Light blue: OPN–Alexa 647; green:
Sox9–Alexa 488; red: tdTomato; gray: DAPI and DIC. Scale bars: 200 µm and 50 µm
(inset). (C–C′) Sagittal sections of Msx2-creER;
R26RTomato posterior cranial vault at P28 (tamoxifen at E10.5)
stained for OPN, periostin (POSTN), and nuclei. Inset: magnified view of the dotted
area of the suture. Light blue: OPN–Alexa 647; green: POSTN–Alexa 488; red: tdTomato;
gray: DAPI and DIC. Scale bars: 500 µm and 20 µm (inset). (D–D′′)
Sagittal sections of Osx-creER; R26RTomato mandibles at P0
(tamoxifen at E13.5) stained for Sox9, OPN, and nuclei. DP, dental pulp; M1,
mandibular first molar; M2, mandibular second molar; Me, Meckel’s cartilage. Light
blue: OPN–Alexa 647; green: Sox9–Alexa 488; red: tdTomato; gray: DAPI and DIC. Scale
bars: 500 µm (D) and 50 µm (D′–D′′). (E) Sagittal sections of
Osx-creER; R26RTomato posterior cranial vault at P0
(tamoxifen at E13.5) stained for Sox9, OPN, and nuclei. Inset: magnified view of the
transitional area. UC, underlying cartilage. Light blue: OPN–Alexa 647; green:
Sox9–Alexa 488; red: tdTomato; gray: DAPI and DIC. Scale bars: 200 µm and 50 µm
(inset). (F–F′) Sagittal sections of Osx-creER;
R26RTomato posterior cranial vault at P28 (tamoxifen at E13.5)
stained for OPN, POSTN, and nuclei. Inset: magnified view of the dotted area of the
suture. Light blue: OPN–Alexa 647; green: POSTN–Alexa 488; red: tdTomato; gray: DAPI
and DIC. Scale bars: 500 µm and 20 µm (inset).