A Cre-loxP based mouse model for conditional somatic gene expression and knock-down in vivo using avian retroviral vectors

Site and time-specific somatic gene transfer using the avian sarcoma-leucosis retrovirus RCAS, has been shown to be a powerful tool to analyze gene function in vivo. RCAS retroviruses transduce only mammalian cells genetically engineered to express the avian retroviral receptor, TVA. Here, we have generated a knock-in mouse line termed LSL-R26Tva-lacZ with concomitant conditional expression of TVA and lacZ by targeting the Rosa26 locus. A loxP flanked transcriptional stop cassette was used for conditional activation of TVA and LacZ expression in a Cre recombinase dependent manner. To demonstrate the ability of t…