Using Red/ET recombination, the sequence encoding Dre recombinase together with a kanamycin/neomycin resistance cassette replaced the ATG start codon of the mouse Pomc gene of RP11-124K7 BAC clone. Five of seven transgenic lines showed similar specificity in the ARC and in the anterior and intermediate lobes of the pituitary. Line numbers were not indicated. The pound symbol (#) is used when no line is specified and/or lines are pooled.