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

Figure 4 Phenotypic and intestinal pathological changes in Cldn7 cKO mice. A: Genotype analysis showed the mice numbered 215 and 217 were intestinal specific Cldn7 cKO mice with the genotype Cldn7fl/fl; villin-CreT; B: Cldn7 cKO mice were normal at birth, but their body lengths increased more slowly from the fifth day after birth than those of control mice (P < 0.05); on the 9^th day, cKO mice were in poor spirits and died thereafter; C: Cldn7 expression was normal in the lung, stomach, bladder ,and kidney tissues of cKO mice but absent in the small and large intestines; all tissues of the control mice expressed Cldn7; D: Intestinal hematoxylin-eosin staining in Cldn7 cKO mice showed connective tissue hyperplasia with extensive inflammatory cell infiltration in the submucosa (as indicated by the arrow); mucosal epithelial vacuolar degeneration can be observed after magnification (as indicated by the arrowhead); there were no obvious histopathological changes in fl/fl CreW mice. Cldn7: Claudin-7; cKO: Conditional knockout.