A transgene consist of the CAG gene promoter, loxP-CAT gene-loxP-mouse Zfp418 region. In the absence of Cre-recombination, the CAG promoter drives the expression of the cat reporter gene but not Zfp418. When Cre-mediated recombination removes the floxed cat reporter, CAG drives the expression of Zfp418. The pound symbol (#) is used when no line is specified and/or lines are pooled. (J:251673)