Fig. 5.

Vascular differentiation is induced by FGF-10 in E12 fetal murine lung explants. Beads coated in FGF-10 or PBS (control) were grafted onto E12 murine fetal lung explants from Tie2-LacZ transgenic mice. Explants were maintained at fetal Po₂ for 48 h, fixed, and then stained for LacZ reporter expression. Grayscale images on left show bead location and morphogenesis over 48 h; color images on right show subsequent expression of Tie2-LacZ reporter gene with bead excised. Bead position is indicated as: F (FGF-10), P (PBS). Combined treatment indicates PBS and FGF-10-coated beads grafted onto the same explant. Note lack of Tie2-LacZ expression in the peripheral mesenchyme (PM) shown in bottom image. Findings shown in these images were replicated across explants isolated from 3 independent litters.