MYOD1 and Duchenne muscular dystrophy: On the other hand, when cultured in vitro for 4 days, the number of Pax7- or MyoD-positive satellite cells derived from the masseter muscle of DMD rats was significantly lower than that of WT rats (Fig. 4F, G, Supplementary Fig. 4A and B), while the number of satellite cells derived from the tongue muscle of DMD rats was only slightly lower than that of WT rats (Fig. 4F, G, Supplementary Fig. 4A and B).