Tg(Sp7-tTA,tetO-EGFP/cre)1Amc

A tTA-regulated GFP::Cre construct, which has the tetracycline-regulated transactivator (tTA) cassette upstream of a tetracycline-responsive element (tetO)-controlled Enhanced Green Fluorescent Protein/cre fusion protein was used to modify a bacterial artificial chromosome (BAC) encoding exon 1 of the mouse Sp7 gene (formerly osterix or Osx1). An frt-flanked selection cassette following the tTA-regulated GFP::Cre was removed from correctly targeted bacteria via transient flpe expression. A 5.2 kb portion of the modified BAC (Osx1-GFP::Cre) was used for pronuclear injection into fertilized CD1 embryos. (J:114494)