Early embryonic lung organ culture is a very useful system to study epithelial-mesenchymal interactions. Both epithelial and mesenchymal morphogenesis proceeds under specific conditions that can be readily manipulated in this system.
Carraro, G., del Moral, P., Warburton, D. Mouse Embryonic Lung Culture, A System to Evaluate the Molecular Mechanisms of Branching. J. Vis. Exp. (40), e2035, doi:10.3791/2035 (2010).