Gene targeting strategy for B-hCXCL13 mice. The exons 1~4 of mouse Cxcl13 gene that encode the full-length protein were replaced by human CXCL13 exons 1~4 in B-hCXCL13 mice.

Strain specific analysis of CXCL13 gene expression in wild-type C57BL/6 mice and homozygous B-hCXCL13 mice by RT-PCR. Mouse Cxcl13 mRNA was detectable in splenocytes of wild-type C57BL/6 mice (+/+). Human CXCL13 mRNA was detectable only in homozygous B-hCXCL13 mice, but not in wild-type mice.

Strain specific CXCL13 expression analysis in homozygous B-hCXCL13 mice by ELISA. Serum were collected from wild-type C57BL/6 mice and homozygous B-hCXCL13 mice (H/H), and analyzed by ELISA with species-specific CXCL13 ELISA kit. Mouse CXCL13 was only detectable in wild-type mice. Human CXCL13 was exclusively detectable in homozygous B-hCXCL13 mice but not in wild-type mice.