SDH and COX staining shows oxidative defects in multiple ERRα/γ dmKO muscles, and pathology reminiscent of minicore myopathies in soleus. A) SDH and COX staining of GC, soleus and plantaris (top two rows) and TA and EDL (bottom two rows) of ERRα/γ dmKO and control WT littermates. Whole muscle sections are composites of multiple images; scale bar in magnified images is 100 μm). B) Consecutives sections of soleus, stained for SDH, COX, type I and type IIa MHC, highlight pathological features in ERRα/γ dmKO muscles, compared to control WT littermates. Yellow and red arrows point to examples of type I and type IIa fibers, respectively. Yellow arrows in sections of ERRα/γ dmKO soleus indicate examples of fibers with areas devoid of SDH, and in particular COX activity. Additional examples are in Suppl. Fig. 3D. All images are representative of sections from 3 mice/group, 6-month-old.