A targeting construct containing the eGFPCreERT2 (GCE) cassette and Frt site flanked Kanamycin/neomycin selection cassette was inserted into the consensus start ATG codon of the gene in a BAC (RP23-183L17). The PGK-Neo/Kan cassette was removed by transient Flpe-recombinase expression. The resulting BAC transgene was microinjected into (C57BL/6 x DBA)F1 donor eggs. Founder line 30 was subsequently established. Native GFP expression is detectable in the urogenital system of E15.5 embryos. Transgenic cre expression is detected in developing nephrons of the kidney, Wolfian and Mullerian ducts and vasculature of the urogenital system of hemizygous 15.5 dpc embryos. Possible cre recombinase activity is detected in small renal arteries.