DNA encoding the cre/ERT2 open reading frame, a bovine growth hormone (BGH) polyA tag, and an frt-flanked kanamycin selection cassette was inserted into the first exon of the Prrxl1 gene in BAC clone RP23-199P8 by homologous recombination in EL250 bacterial cells. Flp expression was induced to excise the kanamycin cassette. The purified BAC construct was injected into FVB/N fertilized eggs. Founder information is not available. (J:187485)