Fig. 14

Increased DUX4-fl expression in the moderate and severe FSHD-like model mice leads to accumulation of fibrotic tissue in skeletal muscles. Histological cross sections of TA muscles dissected from mild, moderate, and severe FSHD-like model mice that had undergone treadmill exhaustion analysis 2× per week (see Figs. 7 and 8). Age-matched female control mice were used for the moderate model analysis and male control mice for the severe model analysis. Muscles were assayed from ACTA1-MCM TMX controls at MD28 (a) and SD9 (b), from mild model at MD28 (g), from female moderate model at MD3 (b), MD6 (c), MD14 (d), and MD28 (e), and from male severe model at SD3 (h), SD6 (i), and SD9 (j). Representative histology images are shown. Quantitative analysis of data is shown in Figure S15. Scale bars = 500 μm