Fig. 2 |. Identification of a sutural DDR2⁺ CSC.

a, DDR2⁺ cells, LAM, Ctsk-Cre;mTmG mice, P7. b, FACS, P7. Pregated on Lin⁻Thy-1.2⁻6C3⁻. c, DDR2, WT and Twist1^Ctsk;mTmG mice, P14 (i), iDTR^Ctsk mice, P21 (ii). d, DDR2⁺ CSCs by FACS (Lin⁻6C3⁻Thy-1.2⁻CTSK-mGFP⁻CD200⁺CD105⁻CD51⁺DDR2⁺) in the sutures of WT (n=13), Twist1^Ctsk (n=20), P7 to P10 (i), and iDTR^Ctsk mice, PBS (n=4) or DT (n=3) at P21 (ii). e, In vivo intramuscular serial transplantation. f, FACS of DDR2⁺ CSC-derived cells after serial transplantation. Black arrows, parent/daughter gates. Red boxes, DDR2⁺ CSCs. Representative of 4 independent experiments. g, FACS showing no interconversion between tdTomato⁺ DDR2⁺ CSCs and mGFP⁺ CTSK⁺ CSCs isolated from Ctsk-Cre;mTmG mice after the first round of transplantation. h, Lineage tracing of sutural DDR2⁺ cells using Ddr2-CreER;mTmG mice over an 18 month chase. i, FACS plots showing total H2B-GFP label-retaining cells after 6 months of chase post-doxycycline (Dox). j, GFP signal intensity histogram of Lin⁻Thy-1.2⁻6C3⁻DDR2⁺ or DDR2⁻ populations after 6 (n=9) or 12 months (n=8) of chase. Label-retaining cells (LRCs) were determined as gated. Green, CD200⁺CD105⁻ (CSC); Blue, CD200^variableCD105⁺; Red, CD200⁻CD105⁻. k, LAM, H2B-GFP mice after 6 months of chase with DDR2 immunostaining. In all graphs, each of dot represents an individual mouse. ****P < 0.0001. Mean ± s.d., unpaired two-tailed Student’s t-test (d). Images in a, c, h, k are representative of at least three independent experiments. Scale bars, 100 μm, a, c, h (left), k; 50 μm, a (far-right); 20 μm, c, h (right), k (inset).