FIG. 3.

Mice homozygous for the Eng Δex5-6 allele have an embryonic lethal phenotype and do not express endoglin protein. (A) Diagram showing generation of the Eng Δex5-6 allele following deletion of exons 5 and 6 in the presence of Cre, and position of primers w, x, and y. (B) Multiplex PCR using primers w, x, and y produce a 602 bp product from the Eng Δex5-6 allele and a 430 bp product from the wildtype allele. (C) EngΔ/Δ embryos at 9.5 dpc show angiogenesis defects in the yolk sac compared with normal vessels (arrows) in their wild type littermates. (D) Wholemount immunohistochemistry of wild type and EngΔ/Δ showing CD31 and endoglin expression. There is clear evidence of CD31 positive endothelial cells in the EngΔ/Δembryos but endoglin protein was not detected.