ObjectiveTo develop mouse colitis model by inactivating ACE2 gene via TALEN technology.Methods A pair of TALENs targeting mouse ACE2 gene was designed and constructed, and in vitrotranscripted mRNA was microinjected into the cytoplasm of zygotes.Genetically-disrupted mice were subjected to 5% DSS challenging prior to histopathology analysis and transcription analysis of the inflammatory cytokines of the colon tissue.Results Somatic mutations were induced with an efficiency of 57% , of which 39% were frame-shift mutations.These modifications were stably transferred during germ-line transmission.In ACE2-knockout mice, we observed more severe colitis phenotype in condition of DSS stress, which was characterized by more body weight loss, severe diarrhoeaand shortened colon length.Histologically,ACE2 mutation resulted in the infiltration of large numbers of lymphocytes and the overt damage of intestinal mucosa.In addition, we detectedthe significantly increased expression of inflammatory cytokines, IL1B, IL6, IL10, IFNG and TNF-αin the colon tissueof ACE2-deficienct mice.Conclusion Evidence from phenotype, histopathology and molecular levels demonstrated that the deletion of ACE2 resulted in more susceptible to colitis, suggesting that TALEN could be a superior strategy to develop gene-knockout models in mouse.