These transgenic mice express an optimized reverse tetracycline-controlled transactivator, rtTAS*M2, or rtTA2S-M2, under the control of the mouse Axin2 expression cassette (which contains 2883 nucleotides upstream of exon 1, exon 1, intron 1 and part of exon 2). Transgene expression mimics the endogenous Axin2 expression pattern, and is detected in dorsal neural tube neuroepithelial cells, migrating neural crest cells, and branchial arch post-migratory neural crest cells. When mated to a second transgenic strain carrying a gene of interest under the regulatory control of a tetracycline-responsive promoter element (tetO), expression of the target gene may be regulated by the tetracycline analog, doxycycline (dox); in the presence of dox, transcription of the target gene is induced in cells where rtTA is expressed. Mice that are hemizygous for the transgene are viable, normal in size and do not display any gross physical or behavioral abnormalities. The Donating Investigator has not attempted to make this strain homozygous.
