Fig. 2. Scx-Cre mice can be used to target both tendon cells and myofibroblasts.

(A) Scx-Cre mice were crossed to ROSA-Ai9 reporter mice to label and trace Scx-lineage (Scx^LinAi9) cells (red) during homeostasis (uninjured) and throughout healing at days 7, 14, and 21 post-surgery. N=3–4 mice per timepoint. Sutures labeled by *. Scale bars, 20 μM (uninjured) and 100 μM (post-surgery). (B) Co-immunofluorescence of tdTomato (labels Scx^LinAi9 cells, pink), αSMA+ myofibroblasts (blue), and phospho-p65+ (green) cells in Scx^LinAi9 mice at days 14 and 28 post-surgery. The white boxes in the upper images indicate the regions shown below in the higher magnification images. N=3–4 mice per timepoint. Scale bars, 200 μM (upper) and 50 μM (lower). For all images, nuclei were stained with DAPI (blue in (A), grey in (B)). Auto-fluorescent muscle is labeled. Examples of positive stain are indicated by white arrows. Tendon stubs are outlined by white dotted lines and scar tissue by yellow dotted line.