Fig. 8. Capillary vessel malformations in the genital tubercle of Hoxa13 deficient embryos. (A) Capillary vessel localization detected by the vascular endothelial marker CD-31 (Pecam; red) in E13.5 heterozygous male embryos. Note the strong co-localization of Hoxa13^GFP(green) with the Pecam-positive capillary endothelial cells (yellow), as well as the symmetric arrangement of capillary vessels around the UPE (arrowhead). (B) Expansion of the capillary vessels in the E13.5 homozygous mutant genital tubercle. Arrowhead denotes a typical sevenfold expansion in vessel diameter in the mutant genital tubercle. Note the lack of Hoxa13^GFP co-localization (yellow) with Pecam in the capillary vessels in the mutant GT. Scale bar: 50 µm.