Fig. 3. FRET images of homomeric connexin formation in NEB1 keratinocytes. The first three rows show pairs of cells co-transfected with (wt)Cx26-ECFP and (wt)Cx26-EYFP, (wt)Cx30-ECFP and (wt)Cx30-EYFP, and (wt)Cx31-ECFP and (wt)Cx31-EYFP. These co-transfections clearly show large gap junction-like aggregates of the fusion proteins at the cell-cell interface. In contrast the three cells in contact presented in the fourth row co-transfected with (wt)Cx30.3-ECFP and (wt)Cx30.3-EYFP did not show any aggregates at the plasma membrane. Left-hand panels are (wt)Cx-ECFP images, middle panels, (wt)Cx-EYFP images and right-hand panels, merged images. Bar, 10 µm.