Figure 3

Dose–response of muscle lesion area in mouse TA 1-week post hIMEP procedure. (A,B) Lesion area percentage was evaluated (A) on total cryosection or (B) in the injected area (defined by β-gal⁺ region) from distal, medial and proximal part of TA electroporated with different doses of control or DUX4-expression plasmid and 10 µg of pCMV-lacZ. Sections were stained with HEB and lesions were quantified by color thresholding using ImageJ. Control groups (Ctrl) include 1-, 20-, 40-µg pCIneo-injected groups as there was no statistical difference among them (one-way ANOVA followed by Dunn’s post hoc test, p = 0.959 and 0.153 for total and injected region quantifications respectively, NS). (C) Comparison of injured area percentages quantified on total section (black) or in injected area (defined by the β-gal⁺ region) (grey). DUX4 groups include 1-, 5-, 20-, 40-µg pCIneo-DUX4-injected groups as there was no statistical difference among them (one-way ANOVA followed by Dunn’s post hoc test, p = 0.894 and 0.957 for total and injected regions respectively, NS). All results are presented as boxplots, ****p < 0.0001, **p < 0.01, (vs ctrl (A,B) or as indicated (C)). (A,B) One-way ANOVA on the ranks followed by Dunn’s post hoc test; n = 3, except 5 µg DUX4 (n = 4), 40 µg DUX4 (n = 5) and Ctrl (n = 11). (C) Wilcoxon signed rank test; n = 11 (ctrl) or 15 (DUX4). Graphs were generated using GraphPad Prism 6.01.