Optical sections from recombined tissues, color coded by origin of epithelia for (K) nuclear red fluorescent protein (RFP)-labeled MDCK cells, and (L) no epithelium (negative CDH1 stain). Dashed lines demarcate folded epithelial-mesenchymal interfaces at sites of mesenchymal aggregation. Recombined tissues in (K) and (L) were incubated in the presence of 1 M SAG. Representative of at least 9 tissue recombinants per condition.
