Claudin-7 gene knockout causes destruction of intestinal structure and animal death in mice

Figure 5 Phenotypic and intestinal pathological changes in Cldn7 ICKO mice. A: Genotype analysis showed that mice numbered 135-137, 139-142, and 144 were Cldn7 ICKO mice with the genotype Cldn7fl/fl; villin-CreERT2; B: Cldn7 cKO mice were normal at birth and developed smoothly, but beginning at the 7^th injection, ICKO mice were in poor health and appeared to be dying; all ICKO mice died within 15 tamoxifen injections; C: Cldn7 was expressed at normal levels in the lung, stomach, bladder, and kidney tissues of ICKO mice but absent in the small and large intestines; all tissues of the control mice expressed Cldn7; D-O: Intestinal hematoxylin-eosin staining in ICKO mice showed obvious inflammatory manifestations; atypical hyperplasia and intestinal adenoma were also observed; the intestinal structure of the control mice was normal. Tamoxifen was dissolved in sunflower oil at a concentration of 10 mg/mL, and each mouse was intraperitoneally injected at 1 mg every 5 days. Cldn7: Claudin-7; cKO: Conditional knockout; ICKO: Inducible conditional knockout.