Figure 6: pCPCs transplanted in skeletal muscle formed muscle bundles that expressed connexin 43, the gap junction protein expressed in cardiac intercalated disks. (A and B) Masson’s trichrome staining of the transplanted TA muscle showed pCPC transplanted cells in the injection track (pointed by arrow) forming muscle like tissues (B). Notice that pCPCs did not form fibrotic tissues (no green or blue collagen tissue was seen in the injection site). (C-F) Transplanted TA muscle was stained with anti-GFP (Alexa 488) (D), connexin 43 (Alexa 594) (E) and DAPI (F, merged with DAPI). (C) Montage of the pCPCs transplanted tissue along the TA muscle identified as GFP+ and connexin 43 positive. (D-F) Higher magnification of transplanted tissue showed connexin 43 expression at cell-cell membrane boundaries. (G) Masson’s trichrome staining of transplanted TA muscle of over 100 µm distant to (A) also showed transplanted pCPCs in the injection track. (I) An adjacent slide of area depicted by arrowhead was positive for cardiac Troponin-T Alexa 647. I. In this area transplanted pCPCs identified as GFP+ were also connexin 43 positive. Scale bars = 100 µm.