Generation of a self-cleaved inducible Cre recombinase

In order to make CreER enter the nucleus, Cre loxP homologous recombination occurs, the reporter gene is expressed, the cells we are interested in are labeled, and the fate of these labeled cells is traced in vivo. We constructed Npr3 screer transgenic mice expressed in endocardial cells and Col1a2 screer transgenic mice expressed in fibroblasts, and compared them with traditional Npr3 screer and Col1a2 screer transgenic mice. There was no significant difference in recombination efficiency between screer and traditional creer when it was recombined with allele such as R26 tdtomato. When recombined with R26 confetti, R26-LZLT, R26-GFP or Vegfr2 flox/flox alleles, the recombining efficiency of screer was significantly higher than that of traditional creer. Compared with traditional creer, screer can significantly improve the recombination efficiency of inducing gene expression or knockout, and can achieve time controllable and efficient genome modification in vivo. During the experiment, we randomly divided the experimental rats and the control group, and each group had 3-5 biological replicates. We used the Zeiss (V16) fluorescence microscope to image the whole tissue; The frozen section specimens were prepared by thermo frozen section machine; Olympus (FV1200) and Nikon (A1) confocal microscopy were used for fluorescence imaging of tissue sections; BD flow cytometry was used for cell sorting; Image experiment results were analyzed by image J; The experimental results were analyzed by prism.