Extended Data Figure 2. Characterization of Axin2+ Wnt responsive cells in the adult lung.

(A) 3 month lineage tracing shows a stable population of AEPs and progeny in the alveolar epithelium. (B–C) Quantification of AT1 and AT2 cells labeled by the AEP lineage mark at homeostasis. 7d lineage tracing data is re-plotted here for comparison to later time points. (D–I) Lower power (D–F) and higher power (G–I) images showing expansion of AEPs in a regional fashion 1 month after influenza injury. Dotted white line in F shows the edge of a Krt5+ pod, with a dearth of AEP-lineage labeled cells. G–I show additional channels of the same fields as Fig 1IJ. (J) Representative FACS plot showing expansion of AEP-lineage labeled epithelial cells following influenza. Quantification found in Fig 1N. (K–O) Comparison of AT2 and AEP Ki67⁺ expression following influenza. Ki67⁺ AEPs re-enter the cell cycle almost exclusively compared to AT2s in areas of regeneration. Data shown in this figure represent N=5 (J–O), N=6 (A–C), or N=10 (D–I) independent animals from 3 individual experiments, except for the 9 month lineage tracing which was performed in two separate experiments. Statistics are representative of all biological replicates. All data is shown as centered on mean with bars indicating standard deviation. *=p<0.05, **=p<0.01, ***=p<0.001, ****=p<0.0001 by ANOVA with preplanned pairwise comparisons and adjustment for multiple comparison testing. Scale bar=50μm.