Fig. 2.

Immunofluorescence analysis of collagen VI α6 in human muscle.

a: Collagen VI α5 chain localization in transversal sections of tibialis anterior (extra-junctional, left panel) and of soleus at the insertion to the Achille's tendon (MTJ, middle and right panels). The α5 chain (green) is absent in the interstitium of tibialis anterior, while it is selectively expressed at the myotendinous junction of soleus (arrows) where it co-localizes with the laminin α2 chain (red), a marker for basement membranes. Bar, 100 μm in left and middle panels, and 20 μm in right upper and lower panels. Nuclei were counterstained with DAPI (blue).

b: Double labeling with anti-α5 chain (green) and anti-pFAK (red) antibodies, of a section of soleus at the insertion to the Achille's tendon, reveals that the α5 chain is expressed at the extracellular side of myotendinous junctions, where pFAK labeling is concentrated. The merged image shows a clear correspondence of the two labeling patterns. Bar, 20 μm. Nuclei were counterstained with DAPI (blue).