A loxP site was inserted downstream of exon 1 and a cassette containg a 5' loxP site, alkaline phosphatase gene and an frt-flanked neo gene was inserted downstream of exon 2. Germ line, flp-mediated recombination was used to remove the neo cassette leaving exon 2 floxed and the alkaline phosphatase gene intact. This is a floxed allele and a reporter allele. (J:136390)