Fig. 2.

Gli1⁺ cell lineage contributes to the postnatal enthesis. (A-G) Pulse-chase cell lineage experiments using Gli1-CreER^T2;R26R-tdTomato mice demonstrate the contribution of Gli1 lineage cells to various entheses. Gli1⁺ cells were labeled by a single tamoxifen administration at different time points (E9.5-E15.5) and their descendants were followed to P0 and P14. (Aa-Fa) The DT enthesis was extensively marked after tamoxifen administration at E13.5 and E15.5. (Ab-Fb) tdTomato⁺ cells were identified in the TM enthesis starting at E10.5; however, a stronger signal was seen following tamoxifen administration at E13.5 or later. (Ac-Fc) tdTomato⁺ cells were identified in the Achilles tendon enthesis following tamoxifen administration at E9.5 and E15.5. On the right of each image, a corresponding H&E section shows the enthesis region. (Ga-Gc) Both DT and TM, but not the Achilles entheses, were extensively marked at P14 following tamoxifen administration at E13.5. Dashed line demarcates the enthesis. Scale bars: 50 µm.