Gene targeting strategy for B-hROBO4 mice. The exons 1-9 of mouse Robo4 gene that encode the extracellular domain were replaced by human ROBO4 exons 1-9 in B-hROBO4 mice.

Strain specific analysis of ROBO4 gene expression in wild-type C57BL/6 mice and homozygous hROBO4 mice by RT-PCR. Mouse Robo4 mRNA was detectable in wild-type C57BL/6 mice (+/+). Human ROBO4 mRNA was detectable only in homozygous B-hROBO4 mice but not in wild-type mice.

Strain specific ROBO4 expression analysis in homozygous B-hROBO4 mice by western blot. Lung tissues were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hROBO4 mice (H/H), and analyzed by western blot with anti-ROBO4 antibody. Human ROBO4 was exclusively detectable in homozygous B-hROBO4 mice.