Fig. 7. Bmp4 expression is downregulated in G6-Nkx DH lungs. Immunohistochemistry using a Bmp4 antibody was performed to determine the expression of Bmp4 in the developing lungs of E12.5 wild-type (A), Gata6^+/- (B), Nkx2.1^+/- (C) and G6-Nkx DH (D) embryos. Bmp4 expression was significantly reduced in G6-Nkx DH lungs, but was unchanged in Gata6^+/- and Nkx2.1^+/- lungs. Inset for each panel is a higher magnification of a single distal airway. Q-PCR was performed using oligonucleotides listed in Table 3 to quantitatively determine the decrease in expression of Bmp4 in G6-Nkx DH lungs at E12.5 (E). Three samples from each indicated genotype were evaluated in these assays. ^*P<0.001 wild-type versus G6-Nkx DH samples. Scale bars: 100 µm in A-D.