Representative images of rat, mouse, and human muscle showing type I/IIA hybrid fibers.

<p>Panels A–C (rat RG), D–F (mouse soleus), and G–I (human VL) are images of muscle cross-sections incubated concurrently with primary antibodies against MHCI (BA-F8) and MHCIIa (SC-71) showing type I (blue), type IIA (green), and type I/IIA (blue and green) fibers. Bars represent 50 µm.