·To construct inducible CRISPR/Cas9 system for studying gene function in mouse immune cells, combining Dox-inducible single guide RNA (sgRNA) expression vector with Cas9 transgenic mice.
·U6-TetO-sgRNA and EF1α-T2A-Puro-BFP-T2A-TetR fragments were obtained by gene synthesis. The two synthetic fragments were assembled into the retroviral vector backbone by using homologous recombination. sgRNA targeting protein coding region of F4/80 and non-targeting control (NC) were designed. Bone marrow cells were isolated from Cas9 transgenic mice and transfected with retrovirus expressing sgRNA. The experimental conditions were divided into Dox-added group (Dox +) and non Dox-added group (Dox-). The knockout effect was tested by flow cytometry and T7 endonuclease Ⅰ (T7EⅠ) experiments.
·①Dox-inducible sgRNA retroviral vector and Cas9 transgenic mice were successfully constructed. ② The result of flow cytometry showed that F4/80 was only knocked out in the F4/80
·An inducible CRISPR/Cas9 system combining Dox-inducible sgRNA retroviral vector with Cas9 transgenic mice are successfully constructed. With this system, inducible gene knockout in mouse immune cells are successfully achieved.