Fig. 2

Cre-mediated dual fluorescent (mT/mG) reporter transgenic for intravital lineage tracing in the kidney. a After Cre-mediated recombinant modification, mT/mG mice were transformed from the expression of tdTomato to EGFP. In addition, both tdTomato and EGFP expressed by the mouse have cell membrane targeting properties. Therefore, the mouse can display the labeled cells in a fluorescent color different from the unlabeled cells under excitation light conditions, greatly improving the observation resolution. b Immunofluorescence image of healthy renal tubules in a double-fluorescent reporter transgenic mouse (Sox9-Cre^ERT2; R26^mTmG) treated with tamoxifen using TPM. In this mouse, intraperitoneal injection of tamoxifen effectively labeled Sox9⁺ cells and their progeny with membrane-located EGFP, while other cells were labeled with membrane-targeted tdTomato. The renal cells in the sham group were basically all tdTomato⁺, indicating that the majority of normal adult kidney cells were Sox9⁻. c After kidney injury, Sox9⁺ cells expanded in large numbers (showing EGFP fluorescence). Reproduced with permission from Ref. [5]