A stabily transfected C2C12 cell (skeletal myoblast cell line) expressing eGFP (green) and connexin43 (red) making connections with an adult cardiac myocyte in culture. Nuclei labelled with DAPI (blue).
Patern of connexin expression in the neonatal heart towards the top of the interventricular septum. The working cardiac myocytes of the septum express Cx43 (blue) and the bundle branches of the conduction system express Cx45 (green) and Cx40 (red).