Fig. 5. Representative images of microinjections in confluent cultures of myometrial cells with the gap junction permeable tracer Lucifer Yellow (A,C) and phase-contrast images of the same injection (B,D). Dye transfer shown in cultured untreated (A,B) and tamoxifen-treated (C,D) Cx43^fl/fl:SM-CreER^T2 SMCs 5 minutes after Lucifer Yellow microinjection into a single cell (asterisks). The restricted transfer in tamoxifen-treated cells contrasts to the basal transfer in untreated cells. (E,F) Microinjected cells (green) of tamoxifen-treated Cx43^fl/fl:SM-CreER^T2 mice were fixed and stained using antibodies to Cx43 (red). Dye transfer was only present in Cx43-expressing cells (white arrows in E) but absent in non-expressors (F). The overlay of Cx43 and Lucifer Yellow dye is visualized in yellow. Bar, 50 µm (A-D); 20 µm (E,F).