Extended Data Fig. 5

a, Immunofluorescence for indicated sheath markers on Tppp3^CG/+;Pdgfra^fl/fl tendon with same experimental scheme as (Fig. 6c) except for without punch and EdU; 3 independent repeats; dashed line, midsubstance-sheath boundary. b, Experimental scheme and fluorescent images of R-control, Tppp3^CG/+;R26R^tdT, and R-cKO, Tppp3^CG/+;R26R^tdT;Pdgfra^fl/fl; chased 30 d after TMX; 3-4 animals/condition; EdU daily throughout; dashed line, midsubstance-sheath boundary; asterisk, tdT⁺EdU⁺ cell. c, Fluorescent images of R-control and R-cKO of sheath compartment in regenerate area; harvested at 14 dpi and EdU daily throughout; n=3 (R-control), n=4 (R-cKO) animals/condition; dashed line, midsubstance-sheath boundary; arrowheads, eGFP^-tdT⁺ cells. Stacked column for the distribution (in %) of various cell populations (keys at side); mean (%) for specified population (Negative, eGFP⁺, tdT⁺, eGFP⁺tdT⁺) as follows: (R-control; 48.3, 8.0, 2.2, 41.5), (R-cKO; 53.0, 15.1, 10.6, 21.2). Bar graph for average number of sheath cells per injury area; mean = (R-control, 1013; R-cKO, 667). d, Controls for SCX immunofluorescence; anti-SCX antibody reacts strongly to midsubstance cells (arrowheads); n=3 independent repeats. e, Fluorescent micrographs of ScxGFP tissue stained with anti-SCX antibody, 93.6±1.9 (mean±SEM) % of ScxGFP⁺ cells are anti-SCX⁺; 3 independent repeats; dashed line, midsubstance-sheath boundary; arrowheads, anti-SCX⁺ScxGFP⁺ cells. f, Stacked columns for the distribution (in %) of various cell populations (keys at side); n=3 animals; mean (%) per population (tdT^-, tdT⁺) as indicated: R-control (16.7, 16.8), R-cKO (32.7, 13.8). Unpaired two-tail Student’s t-test (c,f); error bars = SEM (c,f); scale bar = 20 (d,e), 30 (b), 50 (a,c) μm.