Fig. 4. Slug overexpression in the chick hindbrain induces ectopic epithelial-mesenchymal transition in the dorsal part of the neural tube. (A) A section from an embryo hybridised with rhoB (blue) and neomycin (red; to detect electroporated cells, see text). There is a clear increase in premigratory crest cells in the dorsal neural tube and a higher amount of rhoB-expressing migratory cells (B). (C,D) Composit images of high power views of the boxed regions in A, corresponding to control and electroporated sides, respectively. Observe the Slug-induced ectopic EMT concomitant with the breakdown of the basement membrane indicated by the white arrow in D. The site of breakdown is confirmed by immunostaining with the basement membrane marker laminin and indicated by stars in E and F.