A construct containing the chicken beta-actin promoter (CAG) with a loxP-STOP-loxP cassette preceding a farnesylated enhanced GFP sequence (eGFP-f) was inserted into intron 1 of the Gt(ROSA)26Sor locus via homologous recombination. Cre-mediated recombination of this allele results in the expression of the EGFP reporter driven by the CAG promoter. (J:149822)