Figure 4.

ACE2 expression in adult mouse lung

(A) UMAP visualization of the integrated scRNA-seq data from mouse lung. Annotations were based on the expression of canonical markers for each indicated cell type available at http://betsholtzlab.org/Publications/LungIntegration/search.html.

(B) Dot plot showing the expression of marker genes for each cluster.

(C) The same UMAP as in (A) with Ace2 expression overlay (dark color represents higher expression, and gray color represents Ace2-negative cells). For (A) and (C), green arrows point at the AT-II cell cluster; blue arrows point at the multiciliated cell cluster.

(D) Bar plot of the normalized expression levels of Ace2 in each cluster. Cell type annotations for each cluster are indicated. Individual bars represent single cells and are colored according to the cluster assignment together with cell number distribution below the x axis.

(E) IF staining for indicated proteins in adult mouse lung. A prominent ACE2 signal is observed in bronchial epithelium. Asterisks mark end of terminal bronchioles. The lower panels show the same microscopic field of the alveolar region with different labels visualized. Arrows provide landmarks and point at SFTPC-positive AT-II cells. Note the overlap between ACE2 and SFTPC in the alveolar region and lack of ACE2 staining of pericytes (labeled by PDGFRβ). No ACE2 IF signal was observed in ECs. Nuclei are visualized by DAPI or Hoechst 33342. Br: bronchi, BV: blood vessel. Alv: alveolar region Scale bars are indicated in the figure.