Figure 2. Rat adult skeletal muscle co-stained with isoform specific antibodies.

A) Co-staining with anti-α-SKA (red) and anti-α-CAA (green) allows the detection of isolated thin α-CAA positive fibers in interstitial connective tissue (transversal sections, a–c: longitudinal section, d–f) and of regenerating muscle fibers expressing both isoforms (longitudinal section, g–l, arrowhead), or only α-CAA (arrow). Merged images are shown on right column. Bars = 50 μm. B) Co-staining with anti-α-CAA (green) and anti-α-SMA (red) shows that α-CAA positive spindle cells are in close connection with α-SMA positive vessel (a–c), that early muscle fiber self-regeneration is characterized by co-expression of both isoform (d–f, arrowhead), although more advanced regenerated fibers are only α-CAA positive (g–i). Merged images are shown on right column. Bar = 50 μm. C) Co-staining with anti-α-CAA (red) and anti-vimentin (green) allows the detection of α-CAA positive muscle spindle cells surrounded by a capsule containing vimentin positive cells (transversal section, a–c) and of regenerating α-CAA positive fibers in contact with vimentin positive cells (longitudinal section, d–f). Merged images are shown on right column. Bar = 50 μm.