Fig. 3: Dlx5-creER⁺ early perichondrial cells contribute to both cortical and marrow stromal compartment.

a–c Cell-fate analysis of Dlx5-creER⁺, Osx-creER⁺, or Fgfr3-creER⁺ cells at E15.5 (pulsed at E12.5), visualized by cre-inducible R26R-tdTomato reporter, with Col1a1(2.3 kb)-GFP reporters for osteoblasts. a E15.5 whole femurs. Scale bar: 200 µm. Right panels: magnified view of the boxed areas. n = 4 mice per each group. b E18.5 whole femurs. Right panels: magnified view of the boxed areas showing perichondrium, growth plate and bone collar. Arrowhead: groove of Ranvier and periosteum. Scale bar: 500 µm. n = 4 mice per each group. c Quantification of lineage-marked tdTomato⁺ cells. Upper left: percentage of tdTomato⁺ cells among total periosteal cells. Upper center: percentage of Col1a1-GFP⁺tdTomato⁺ cells among Col1a1-GFP⁺ cortical osteoblasts. Upper right: percentage of Col1a1-GFP⁺tdTomato⁺ cells among Col1a1-GFP⁺ trabecular osteoblasts. Lower left: number of tdTomato⁺ BMSCs. Lower right: percentage of SOX9⁺tdTomato⁺ cells among SOX9⁺ growth plate chondrocytes. n = 4 mice per each group. Two-tailed, one-way ANOVA followed by Tukey’s post-hoc test. Data are presented as mean ± s.d. Exact P value is indicated in the figures. d Diagram depicting lineage contribution of Dlx5-creER⁺, Osx-creER⁺, and Fgfr3-creER⁺ cells in fetal endochondral bone development, at E15.5 and E18.5. Source data are provided as a Source Data file.