Gene targeting strategy for B-hCLDN2 mice.
The exon 2 of mouse Cldn2 gene that encodes the full-length protein was replaced by human CLDN2 exon 2 in B-hCLDN2 mice.

Strain specific CLDN2 expression analysis in homozygous B-hCLDN2 mice by western blot. Kidney, liver, lung and duodenum were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCLDN2 mice (H/H), and analyzed by western blot with anti-CLDN2 antibody. m/hCLDN2 was detectable in kidney of wild-type C57BL/6 mice and homozygous B-hCLDN2 mice as the antibody can cross-recognize both human and mouse CLDN2.

Strain specific analysis of CLDN2 mRNA expression in wild-type C57BL/6 mice and B-hCLDN2 mice by RT-PCR. Kidney RNA was isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hCLDN2 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CLDN2 primers. Mouse Cldn2 mRNA was detectable only in wild-type C57BL/6 mice. Human CLDN2 mRNA was detectable only in homozygous B-hCLDN2 mice but not in wild-type mice.