Fig. 6. Maintaining a continuous source of Wnt6 or paraxis counters the de-epithelialisation of the dermomyotome. (A) Expression of Paraxis in an embryo injected with Wnt6-expressing cells at E2.5 and incubated for 48 hours. (B) Enlargement of the boxed area in A, showing the maintenance of a high paraxis expression around the injected cells. (C) Fluorescence image of B, showing the position of the DiI-labelled cells. (D) Transverse section of the same embryo. (E) Enlargement of D. Arrow indicates a dermomyotome-like epithelial structure located in the vicinity of the injected cells (outlined). (F-I) Confocal pictures of sections of embryos electroporated with paraxis CLGFPA in the dorsal region of the dermomyotome, stained with antibodies against GFP (in green), ß-catenin (in blue) and phalloidin red, recognising F-actin (in red), (F,G) Twenty-four hours after electroporation, the morphology (shown with GFP staining) and polarity (recognised by F-actin and ß-catenin staining at the adherens junctions) of cells overexpressing paraxis is normal. (G) Enlargement of F. (H,I) Forty-eight hours after electroporation, cells over-expressing paraxis organise in clusters of cells that maintain contacts through their apical ends, expressing F-actin and ß-catenin (arrowheads). (I) An enlargement of H.