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Fig. 4
Mesenchymal cell density and morphology are altered according to the regenerative stage. (A-C) Quantification of average DAPI intensity (in arbitrary units, a.u.) in mesenchymal cells along the PD axis of blastemas at 24hpa (A), 48hpa (B) and 72hpa (C). n=7 sections, 3 fish/condition. (D-F) Representative DAPI-stained longitudinal sections of blastemas at 24hpa (D), 48hpa (E) and 72hpa (F). (G-I) Quantification of average space (a.u.) between mesenchymal cells along the PD axis at 24hpa (G), 48hpa (H) and 72hpa (I). n=9 sections; 3 fish/condition. (J-L) Representative anti-GFP-stained longitudinal sections of ctgfa:eGFP transgenics at 24hpa (J), 48hpa (K) and 72hpa (L). (M) Quantification of average cell aspect ratio of mesenchymal cells at 24, 48 and 72hpa, in which y is the minor axis of the cell and x the major cell axis. A perfect circular shape corresponds to a ratio between y and x of 1. P corresponds to proximal; D to distal regions. ***P<0.0001; two-tailed, non-parametric Mann–Whitney test. n=45 cells/condition; 5 cells randomly selected/image; 9 sections; 3 fish/condition. (N-R) High magnification images of the boxed areas in J-L highlight cell morphology of blastema cells at 24hpa (N); 48hpa proximally (O) and distally (P); and 72hpa proximally (Q) and distally (R). Dashed lines indicate amputation plane. Scale bars: 50µm. Medial blastema areas were considered for all measurements: shadows indicate the s.e.m. for each curve.