Fig. 5: YAP functions in the mesenchyme to promote gut elongation and cell proliferation.

A Photos of E13.5 Dermo1^Cre Yap^lox/+ Taz^lox/+ and Dermo1^Cre Yap^lox/lox Taz^ox/+ intestines. Scale bar, 1 mm. The length of the small intestine was measured from the caudal stomach (orange arrowheads) to the rostral cecum (purple arrowheads). B Lengths of E13.5 in Yap^lox/lox Taz^lox/+ (n = 3), Dermo1^Cre Yap^lox/+ Taz^lox/lox (n = 7), Dermo1^Cre Yap^lox/+ Taz^lox/+ (n = 5) and Dermo1^Cre Yap^lox/lox Taz^ox/+ (n = 9) intestines. Horizontal bars indicate means ± SD. ****p < 0.0001 by one-way ANOVA Sidak’s multiple comparisons test. C Immunofluorescence staining of E12.5 Yap^lox/lox Taz^lox/+ and Dermo1^Cre Yap^lox/lox Taz^lox/+ intestines for EdU (white) and nuclei (Hoechst, blue). Scale bar, 25 μm. Orange dotted lines outline the epithelium. D The percentage of EdU-positive cells in the E12.5 whole intestine, the epithelial cells or the mesenchymal cells in Yap^lox/lox Taz^lox/+ (n = 4) and Dermo1^Cre Yap^lox/lox Taz^lox/+ (n = 3). For each intestine, we averaged the percentages in the indicated cell population from three stained sections. Horizontal bars indicate means ± SD. **p < 0.01 by two-way ANOVA Sidak’s multiple comparisons test (adjusted P are 0.0031 for Total, 0.0014 for Epithelium and 0.0013 for Mesenchyme). E Relative levels of End1, Ano5, and Ccl11 mRNA in E13.5 control (Dermo1^Cre Yap^lox/+ Taz^lox/+, n = 3) and Dermo1^Cre Yap^lox/lox Taz^lox/+ (n = 4) intestines. Values are presented as means ± SEM. *p < 0.05 and ***p < 0.001 by two-sided unpaired t test (0.0114 for Edn1, 0.0005 for Ano5 and 0.0311 for Ccl11). F Immunofluorescence staining of E13.5 Yap^lox/lox Taz^lox/+ and Dermo1^Cre Yap^lox/lox Taz^lox/+ intestines for YAP (red), smooth muscle (αSMA, green) and nuclei (Hoechst, blue). Higher magnifications of boxed regions are depicted in Supplementary Fig. 12B. Scale bar, 25 μm. Source data are provided in the Source Data file.