A transgene was designed with a cre recombinase and nuclear-localization signal sequence on one side, and an enhanced green fluorescent protein (EGFP) sequence on the other side of a bi-directional tetracycline-responsive promoter (tetO; also called tetracycline operator, tet-operator, or tetracycline-responsive element [TRE]) with CMV minimal enhancer-less promoter. Founder line 3 was established. (J:151755)