Fig. 5: Dyrk2^−/− mice exhibit the loss of the Foxf1 expression gradient during early lung development.

Loss of Dyrk2 leads to impaired airway branching with the loss of the Foxf1 expression gradient. a Representative lungs from E11.5 WT and Dyrk2^−/− mice with the epithelium outlined by whole-mount E-cadherin immunostaining. Numbers denote the tip of the lung bud. b Quantification of the number of tips of the lung bud and bronchial width from E11.5 WT and Dyrk2^−/− mice. (WT: n = 6; KO: n = 3). c Optical image of E11.5 lung in WT and Dyrk2^−/− embryos. Ki67 (red) and cleaved caspase 3 (green). Quantification of the number of Ki67 positive cells and cleaved caspase 3 positive cells. (n = 3). d Optical images of E11.5 and E18.5 lung in WT and Dyrk2^−/− embryos. Dyrk2 (red) and DAPI (blue). e, f Optical images of E18.5 (e) and E16.5 (f) lung from WT embryos. Dyrk2 (red), CC10 (club cell marker, green), FoxJ1 (ciliated cell marker, green), Acetylated Tubulin (AcTubulin) (ciliated cell marker, green) and DAPI (blue). g Optical image of E11.5 lung in WT and Dyrk2^−/− embryos. Foxf1 (green), and DAPI (blue). Epi epithelium, Mes mesenchyme. h A subepithelial-to-distal expression gradient of Foxf1 in E11.5 lungs. i Relative intensity of Foxf1 expression in the subepithelial mesenchyme (n = 3). j Relative expression of Foxf1 target genes in E14.5 lungs (n = 3). k Expression levels of Dyrk2 and Foxf1 in E11.5 lung explants treated with or without 50 μM harmine. Relative expression of Foxf1 and its target genes in the E11.5 lung explants (n = 3). l Relative expression of Foxf1 and its target genes in E11.5 lung explants with or without 14.8 nM smoothened agonist (SAG) (n = 3). Data are presented as the mean ± SD in b, c, h–l. *p < 0.05; **p < 0.01. Scale bar: 100 μm (a, d–g), 200 μm (c).