Hprt1^{tm353(Ple274-icre/ERT2)Ems}

The transgene consists of a RP11-1006.F7 human bacterial artificial chromosome (BAC) retrofitted to contain a human HPRT complementary sequence (containing exon 1, intron 1, exon 2 and part of intron 2), a mouse 3' Hprt homology arm, an I-Sce linearization cut site, and a mouse 5' Hprt homology arm; all inserted into the sacB gene in the BAC vector. Next, an iCre/ERT2 fusion gene, an frt-flanked kanamycin cassette were inserted directly at the ATG of the human CRH locus. These transgene is targeted as a single copy "knock-in" into the upstream region of the Hprt mutant locus. Transient infection with FLP recombinase removes the kanamycin cassette. (J:270567)