Fig. 9. Exuberant delamination of neuroepithelial cells in E11.5 Cx43-PCKO embryos. (A-F) P3pro-Cre-expressing control (A) and Cx43-PCKO E11.5 embryos (D), crossed into the EYFP Cre reporter line demonstrate extensive Cre activity throughout the neural tube (nt) and dorsal root ganglia (drg). High-power views of the dorsal (B) and lateral (C) aspects of the control neural tube shown in A demonstrate a sharp boundary at the neuroepithelial border (arrowheads). No cells crossing this boundary are seen. In contrast to controls, neural tube cells in the E11.5 Cx43-PCKO embryo are delaminating from the dorsal (E) and lateral (F) aspects of the neural tube (arrows; asterisked arrow indicates an actively delaminating cell). (G-I) As observed in the Cx43-PCKOs, delamination of cells from Cx43 germline KO (Cx43^fo/fo) neural tubes (G) is detected along the dorsal (H) and lateral (I) surfaces. (J-O) Wnt1-Cre activity is limited primarily to the dorsal regions of E11.5 EYFP-expressing control (J) and Cx43-WCKO (M) neural tubes. Labeled cells are not seen outside either dorsal or lateral aspects of the Wnt1-Cre⁺ control (K,L) or Cx43-WCKO (N,O) neural tubes. EYFP fluorescence appears green, propidium iodide to highlight cell nuclei is red and their overlap results in yellow signal. Scale bar: 200 µm for A,D,G,J,M; 50 µm for all other panels.