Gene targeting strategy for B-hVSIR mice. The exons 2-4 of mouse Vsir gene that encode the extracellular domain were replaced by human VSIR exons 2-4 in B-hVSIR mice.

Strain specific analysis of VSIR gene expression in WT and heterozygous B-hVSIR mice by RT-PCR. Mouse Vsir mRNA was detectable in bone marrow cell of wild-type (+/+) mice and heterozygous B-hVSIR mice (H/+). Human VSIR mRNA was detectable only in H/+, but not in +/+ mice.

Strain specific VSIR expression analysis in homozygous B-hVSIR mice by flow cytometry. Bone marrow and blood were collected from WT and homozygous B-hVSIR (H/H) mice in vivo, and analyzed by flow cytometry with species-specific anti-VSIR antibody. Mouse VSIR was detectable in WT mice. Human VSIR was exclusively detectable in homozygous B-hVSIR but not WT mice.