Fig. 2

Phenotypes of iDUX4pA mice in the basal “off” state. a Weekly average of the weight of iDUX4 and wild type (WT) male and female siblings (n = 3–25). b Normalized mass to the body weight (BW) of various muscles in iDUX4pA males. Extensor digitorum longus (EDL), tibialis anterior (TA), gastrocnemius and soleus (G/S), quadriceps (Quad), triceps brachii (Triceps), pectoralis, psoas major (Psoas), and masseter from 10 to 15 week old mice and age-matched siblings are analyzed (n = 10). c Representative example of hanging wire, grip strength and rotarod analyses of 6-week-old iDUX4pA male and female mice (n = 4). d Specific force, time to reach peak twitch force (TPT) and time to reach 1/2 relaxation during twitch (1/2 TPT) of EDL in 6–10-week-old iDUX4pA males and age-matched siblings (n = 8). e Representative FACS analyses for Lin^neg (CD45^neg; CD31^neg) and PDGFRα⁺ or Sca1⁺ cells in muscle from iDUX4pA males and sibling controls. Percent of PDGFRα⁺ or Sca1⁺ cells in pooled muscle digests comprising TA, gastrocnemius, soleus, quadriceps, pectoralis, and triceps is shown at right (n = 7). f RTqPCR analyses for DUX4, DUX4 targets, myogenic genes, and genes involved in fibrosis in pectoralis from iDUX4pA male mice. Results are presented as fold difference to GAPDH (n = 4). g Auditory brainstem response (ABR) in iDUX4 males, females and WT sibling controls (n = 5, 6–8 week old mice). Note that iDUX4pA males do not respond to sounds of 16 kHz and above and iDUX4pA females to sounds of 32 kHz. All data are presented as mean±SEM; *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 by T-test or g two-way ANOVA followed by Tukey’s post hoc test