Fig. 7. Electroporation of control GFP, cN390-GFP or wtN-cadherin to rostral and caudal lips of the DM. (A-D) Electroporations of control GFP (A,C) and cN390-GFP (B,D) to caudal (A,B) and rostral (C,D) DM lips to somites 22-23 of 28ss embryos. (E) Similar transfection of wtN-cadherin-GFP to a caudal lip. Embryos were re-incubated for 24 hours. In control-treated segments, the labeled lip cells generated fibers that elongated toward the opposite direction (arrows in A, whole-mount view, and in C, frontal section); a similar phenotype is obtained upon wtN-cadherin overexpression (whole-mount view, E, n=7/7). In cN390-GFP-treated lips (B,D), labeled cells lost their epithelial shape, remained in the inter-somitic region and did not generate fibers. Arrowheads indicate the inter-somitic spaces. (F-K) Similar electroporations as in A-D. Whole mounts (F,G) and frontal sections (H-K) were in situ hybridized with a Myod probe and stained for GFP. Each panel shows separately and in combination Myod transcripts and GFP expression. Both caudal and rostral lip cells treated with control GFP, co-express Myod (arrowheads in F, arrows in H,J) and generated myofibers (n=8/9). cN390-GFP-expressing cells (G,I,K) dissociated from the epithelium, do not express Myod (arrowheads in G, arrows in I,K) and did not generate myofibers (n=10/11). DM, dermomyotome; EC, ectoderm; IS, intersomite; R and C, rostral and caudal; Myo, myotome; Scl, sclerotome. Scale bars: in K, 10 µm for C,D; 20 µm for H-K.