The protein encoded by the Angiotensin Converting Enzyme 2 (ACE2) gene belongs to the angiotensin converting enzyme family of dipeptidyl carboxydipeptidases and is homologous to Angiotensin I. ACE2 is expressed in a variety of human organs and has a strong affinity for Angiotensin I (AngⅠ) and Angiotensin II (AngⅡ) receptors. It catalyzes the cleavage of Ang I to angiotensin 1-9 (Ang1-9) and Ang II to angiotensin 1-7 (Ang1-7), which has a vasodilating and antihypertensive effect ^[1], and plays a role in the regulation of blood pressure, fluid balance, inflammation, cell proliferation, hypertrophy, and fibrosis, as well as in the regulation of cardiovascular and renal function and fertility ^[2]. ACE2 is also a common functional receptor for the spike protein of human coronavirus HCoV-NL63 and the severe acute respiratory syndrome coronaviruses SARS-CoV and SARS-CoV-2 ^[3]. This strain is a mouse Ace2 gene knockout model that uses gene editing technology to knock out the homologous gene of human ACE2 in mice. The knockout of the Ace2 gene will result in the absence of ACE2 protein expression, and this model can be used for the study of COVID-19. The homozygous Ace2-KO mice are viable and fertile.

The TAG stop codon was replaced with "P2A-CreERT2" cassette. CreERT2 recombinase is expressed under the regulatory control of Ace2 gene elements. This model is a Tamoxifen-inducible Cre mouse, and when crossed with mice containing loxP sites, the offspring mice are expected to undergo sequence recombination between loxP sites mediated by Cre recombinase in Ace2-positive cells following Tamoxifen induction.

Ace2 is located on chromosome X of mice. Nuclease Technology was used to design sgRNA; Ace2 knockout mice were obtained by applying high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.

Ace2 is located on chromosome X of mice. Nuclease Technology was used to design sgRNA; Ace2 knockout mice were obtained by applying high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.

Ace2 is located on chromosome X of mice. SgRNA and ssDNA were designed using Nuclease Technology; Ace2 conditional knockout mice were obtained by high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.