Intercellular communication in cells expressing Cx43tr alone or co-expressing Cx43tr with Cx43 or Cx45. (A, C, D) Fluorescence micrographs obtained after micro-injection of Lucifer Yellow into a single cell within a confluent monolayer of HeLaCx43tr (A), HeLaCx43/Cx43tr (C), or HeLaCx45/Cx43tr (D) cells. While dye was seen only in the injected cell in the HeLaCx43tr cells, extensive dye transfer was seen in the co-expressing cells. (B) Gap junctional currents recorded from a pair of HeLaCx43tr cells.