Gene targeting strategy for B-hCCR3 mice. The exon 2 of mouse Ccr3 gene that encodes the full-length protein was replaced by human CCR3 exon 3 in B-hCCR3 mice.

Strain specific CCR3 expression analysis in homozygous B-hCCR3 mice by flow cytometry. Bone marrow was collected from wild-type mice (+/+) and homozygous B-hCCR3 mice (H/H). Eosinophils were analyzed by flow cytometry with species-specific anti-CCR3 antibody. Mouse CCR3 was detectable in wild-type mice. Human CCR3 was exclusively detectable in homozygous B-hCCR3 mice but not in wild-type mice.