Tg(Nfatc1-rtTA)96Bz

Homologous recombination was employed to insert a nuclear-localized reverse tetracycline transactivator sequence and Frt-flanked PGK-neomycin cassette at the translational start site in exon 1 of Nfatc1 in a BAC. The neo cassette was removed with Flpe. The purified construct was injected into fertilized FVB 0.5 day-zygotes. Seven founder lines were obtained and bred to tetO-cre;Gt(ROSA)26Sorfslz mice, followed by doxycycline induction for 3 days starting on E7.5. Three lines (96, 100, and 122) showed expression in the endocardium and its mesenchymal descendants in the endocardial cushion. Data from #96 is provided in the original reference. (J:193198)