Fig. 7. Differential mobility of fluorescent-protein-tagged Cx26 and Cx43 within assembled gap junctions. Central regions of gap junction plaques in BICR-M1Rk cells, composed of Cx26-YFP (A-D) or Cx43-GFP (E-H), were photobleached and the fluorescent recovery in the photobleached area was monitored. Note the rapid recovery of Cx26-YFP within 200-400 seconds but little recovery was observed in Cx43-GFP photobleached regions of gap junction plaques. Further FRAP analysis revealed that gap junctions composed of Cx26-YFP had a substantially larger mobile fraction population than Cx43-GFP gap junctions (I). Bar, 5 µm.