Figure 6.

Surfactant protein expression in lungs. Panel A shows the immunostaining patterns for SP-C in lungs at E18.5 and E20.5 from wild-type (+/+) and knockout (-/-) embryos. No significant differences in the patterns of SP-C staining were evident between wild-type and knockout lungs (panel A, a-d). Note that the underdeveloped epithelial tubules in knockout lungs also expressed SP-C (panel A, b and d, arrowheads), indicating normal type II AECs differentiation. Original magnification: 10X. Panel B, left-hand panel, shows a representative result from Northern analyses of total RNA from wild-type, heterozygous and knockout P0 lungs for SP-A, SP-B, SP-C and SP-D expression. Densitometry analyses showed the relative expression (n = 3, mean ± s.d.) of these surfactant protein mRNAs were not significantly different between these three genotypes.