We have developed a method of specifically modifying the mammalian genome in vivo. This procedure comprises heritable tissue-specific and site-specific DNA recombination as a function of recombinase expression in transgenic mice. Transgenes encoding the bacteriophage P1 Cre recombinase and the loxP-flanked beta-galactosidase gene were used to generate transgenic mice. Genomic DNA from doubly tr...

Recently, several systems designed to trigger RNA interference by using small hairpin RNA driven by polymerase III promoters have been described. Here, we report a lentiviral-mediated small interfering RNA delivery system that can be induced by CRE recombinase. The system consists of a lentiviral vector carrying a mouse U6 promoter that is separated from a small hairpin RNA by a random DNA stuf...

The serine recombinases are a diverse family of modular enzymes that promote high-fidelity DNA rearrangements between specific target sites. Replacement of their native DNA-binding domains with custom-designed Cys₂-His₂ zinc-finger proteins results in the creation of engineered zinc-finger recombinases (ZFRs) capable of achieving targeted genetic modifications. The flexibility afforded by zinc-...

Conventional silencing of many podocyte-specific genes in mice is associated with embryonic or perinatal lethality. Therefore, it would be of great importance to generate mouse models that allow the modification of genes that are expressed in podocytes at later stages of age. Herein is described a transgenic mouse with doxycycline-inducible podocyte-specific expression of Cre recombinase. For t...

We describe two retroviral vector-based recombination substrate systems designed to assay for lymphoid VDJ recombinase activity in cultured cells. Both substrates incorporate a constitutive dominant marker gene (the simian virus promoter-driven neo gene) to allow selection of cells that stably integrate the substrate. Both substrates also include a second marker gene that becomes transcriptiona...