Figure 4. Appearance of Sp-C^low AT2 in Dlk1^ΔAT2 Mice after Lung Injury.

(A) mRNA expression of Sp-C in AT2 of WT and Dlk1^ΔAT2 of uninjured and 3-day post-PA injured mice was quantified by qRT-PCR. Data are presented as relative values compared with the uninjured WT. Mean ± SE; *p < 0.05, **p < 0.01.

(B) Flow-sorted Tomato⁺ AT2 cells of WT and Dlk1^ΔAT2 basal and post-injury mice were analyzed by western blotting for Sp-C expression. β-Actin was used as a loading control. Images are representative of three similar observations.

(C and D) Images of lungs in which AT2 were lineage-labeled by YFP. 7 days post-PA injury, most WT AT2 (cuboidal YFP⁺ cells) expressed Sp-C (C), whereas numerous YFP⁺ mutant (Mut) AT2 lacked Sp-C expression (arrows in D). Scale bar, 20 μm.