(a,d) Gross examination of yolk sacs dissected from E10.5 WT (a) and Snail1 LOF (d) embryos. Scale bar: 2 mm.
(b,e) Whole-mount PECAM-1 staining of yolk sac dissected from E10.5 WT (b) and Snail1 LOF (e) embryos. Insets, representative images of whole-mount α-SMA staining. Red lines mark continuous vessels with a diameter > 20 μm. Scale bar: 100 μm.
(c,f) Gross examination of WT (c) and Snail1 LOF (f) embryos with yolk sac at E11.5. Note the absence of vascular structures in the LOF mutant yolk sacs. Scale bar: 2 mm.
(g) Quantification of relative vessel (diameter > 20 μm) length in yolk sacs from E10.5 WT (b) and Snail1 LOF (e) embryos (n=4 each). Data are presented as mean ± SEM. **p < 0.01, Student’s t test.
(h-m) Whole-mount PECAM-1 staining of allantois explants dissected from E8.25 WT (h-j) and Snail1 LOF (k-m) embryos. At pre-culture (h,k), vascularization of allantois explants derived from WT and Snail1 LOF embryos were comparable, whereas at 24 h post-culture, the Snail1 LOF embryo explants display marked defects in their ability to generate vascular structures (i,j,l,m). Cell nuclei were stained with TOTO3 (blue). Scale bar: 100 μm.
(n) Quantification of relative vessel length in the WT and Snail1 LOF explant cultures (n = 5 in each group). Data are presented as mean ± SEM. **p < 0.01, Student’s t test.