SPC-Cre-ERT2 transgenic mouse for temporal gene deletion in alveolar epithelial cells.

Although several Cre-loxP-based gene knockout mouse models have been generated for the study of gene function in alveolar epithelia in the lung, their applications are still limited. In this study, we developed a SPC-Cre-ER(T2) mouse model, in which a tamoxifen-inducible Cre recombinase (Cre-ER(T2)) is under the control of the human surfactant protein C (SPC) promoter. The specificity and efficiency of Cre-ER(T2) activity was first evaluated by crossing SPC-Cre-ER(T2) mouse with ROSA26R mouse, a β-galactosidase reporter strain. We found that Cre-ER(T2) was expressed in 30.7% type II alveolar epithelial cells of SPC-Cre-ER(T2)/ROSA26R mouse lung tissues in the presence of tamoxifen. We then tested the tamoxifen-inducible recombinase activity of Cre-ER(T2) in a mouse strain bearing TSC1 conditional knockout alleles (TSC1(fx/fx)). TSC1 deletion was detected in the lungs of tamoxifen treated SPC-Cre-ER(T2)/TSC1(fx/fx) mice. Therefore this SPC-Cre-ER(T2) mouse model may be a valuable tool to investigate functions of genes in lung development, physiology and disease.