Fig. 4. Connexins are differently expressed in pseudo-islets made of non-infected and transduced islet cells. (A) Two days after transduction with a lentiviral vector coding for GFP, numerous primary islet cells exhibited a high fluorescence in monolayer cultures. When allowed to re-aggregate spontaneously into three-dimensional pseudo-islets, most of these cells still exhibited GFP fluorescence 5 days after the infection. Bars, 22 µm in monolayers and 10 µm in pseudo-islets. (B) Immunostaining confirmed the expression of Cx36 in uninfected pseudo-islets and increased levels of this connexin after transduction. Lentiviral vectors also allowed the formation of pseudo-islets expressing either Cx32 or Cx43. Bar, 10 µm. (C) Bars show the percentage of cells within pseudo-islets featuring GFP fluorescence or immunofluorescence staining for Cx32, Cx36 or Cx43 after infection with the lentiviral vectors. 43 pseudo-islets were scored in four experiments.