• Claudin-1 is a member of the transmembrane protein family claudins located in cell-cell tight junctions and it acts as a co-receptor for HCV entry into hepatic cells. Claudins are abundant in luminal epithelial sheets where they maintain epithelial cell polarity. Claudin-1 is expressed in most tissues such as bladder, fallopian tube, liver, pancreas, prostate, and skin.
• The exons 1~4 of mouse Cldn1 gene were replaced by human CLDN1 exons 1~4 in B-hCLDN1 mice.
• Human CLDN1 mRNA and protein were detectable in homozygous B-hCLDN1 mice but not in wild-type C57BL/6 mice.
• Application: This product is used for pharmacodynamics and safety evaluation of antitumor drugs.

Gene targeting strategy for B-hCLDN1 mice.
The exons 1~4 of mouse Cldn1 gene were replaced by human CLDN1 exons 1~4 in B-hCLDN1 mice.

Strain specific CLDN1 expression analysis in homozygous B-hCLDN1 mice by flow cytometry. Liver was isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hCLDN1 mice (H/H) and analyzed by flow cytometry with anti-hCLDN1 antibody A and B. hCLDN1 was detectable in homozygous B-hCLDN1 mice but not in wild-type C57BL/6 mice.

Western blot analysis of CLDN1 protein expression in homozygous B-hCLDN1 mice. Various tissue lysates were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCLDN1 mice (H/H), and then analyzed by western blot with anti-CLDN1 antibody. 40 μg total proteins were loaded for western blotting analysis. CLDN1 was detected in liver and skin, as the antibody is crossly reactive with CLDN1 in human and mice.

Strain specific analysis of CLDN1 mRNA expression in wild-type C57BL/6 mice and B-hCLDN1 mice by RT-PCR. Various tissue RNA were isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hCLDN1 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CLDN1 primers. Mouse Cldn1 mRNA was detectable only in wild-type C57BL/6 mice. Human CLDN1 mRNA was detectable only in homozygous B-hCLDN1 mice but not in wild-type mice.