Figure 7. The primary cell type in the normally and aberrantly developing septa are type I alveolar epithelial cells.

The impact of administration of scrambled antimiR (S) or an antimiR directed against miR‐34a (A34a) on the abundance of type I alveolar epithelial cells (marked by aquaporin 5, Aqp5) and type II alveolar epithelial cells (marked by pro‐surfactant protein C, Sftpc) was assessed in 3‐μm sections of paraffin‐embedded lung tissue from P5 mice undergoing normal (21% O₂) or aberrant (85% O₂) lung alveolarization. DAPI, 4′,6‐diamidino‐2‐phenylindole. In the DAPI images, white lines delineate tissue from airspaces, and in the 85% O₂ groups demarcate septa. Antibody specificity was validated by rabbit IgG isotype control primary antibodies. The control experiments for the Aqp5 and Sftpc staining runs are illustrated here. Scale bars, 50 μm.