FIGURE 1:

Abnormal blood vessel formation in A^Tie2/A^Tie2 mouse back skins at E14.5. Wholemount confocal images of back skins dissected from A^Tie2/A^Tie2 (b, enlarged in d) and A^flox/A^flox control (a, enlarged in c) mice at E14.5 stained with CD31 antibodies to reveal the developing vasculature (red) show that A^Tie2/A^Tie2 mice have reduced blood vessel coverage, b, compared with A^flox/A^flox mice, a. A^flox/A^flox mice develop mature blood vessels—a, arrows, which are not seen in A^Tie2/A^Tie2 mice, b. The dashed white lines in a and b depict a V-shaped area that has not been fully covered by blood vessels. A^flox/A^flox back skins develop smooth straight vascular sprouts toward the middle of the back—c, arrows. A^Tie2/A^Tie2 back skins show vascular sprouts that contain multiple branches—d, white arrows. Isolated clusters of endothelial cells are observed in the middle of A^Tie2/A^Tie2 back skins—d, yellow arrows—which are not seen in A^flox/A^flox mice, c. Panel e shows the quantification of average angles from A^flox/A^flox and A^Tie2/A^Tie2 mouse back skins, n = 4 for each genotype.