Fig. 8. Bmp7^cre/+;Smad4^–/CA metanephric mesenchyme responds to induction in vitro. Wild-type (WT) and Bmp7^cre/+;Smad4^–/CA (Mut) mesenchyme was cultured with and without LiCl, a potent nephrogenic inducer. Untreated mesenchyme rapidly underwent cell death (A,B), whereas treated mesenchyme survived and underwent nephrogenic induction (C,D). Photographs were taken at the same magnification, and the size difference between induced wild-type and mutant mesenchyme is representative. Histological analysis revealed the presence of epithelial condensates within both wild-type (E) and mutant (F) mesenchyme, and the development of tubular structures within the wild type. Basal deposition of laminin surrounding condensates was confirmed by fluorescent immunostaining (G,H). C, condensate; T, tubule.