Mice hemizygous for the transgene are viable, fertile, normal in size, and do not display any behavioral abnormalities. At the Jackson Laboratory, no homozygous mice were produced from mating hemizygotes together, suggesting that homozygous transgenic animals die in utero. Expression of the bicistronic transgene is under the regulation of a tetracycline promoter element (TRE; tetO). By themselves, these transgenic mice do not express EGFP, but when these mice are mated with a second transgenic strain expressing tetracycline-transactivator (tTA) protein under the control of a tissue-specific promoter, Ipf1 and EGFP are highly expressed in the appropriate tissue of bitransgenic offspring.
This mouse was originally designed to be mated to an apancreatic targeted mutant with tTAoff in place of the endogenous Ipf1 gene (see Stock No. 005701). The combined mutations allow normal pancreatic development and function until doxycycline treatment renders the double mutant mouse conditionally null for Ipf1 expression. Using these double transgenic mice, pancreatic developmental can be arrested at any stage during embryonic development or in adult mice. Such double mutant mice may be useful in studies of pancreatic endocrine/exocrine function and diabetes. Tg(tetO-Ipf1,EGFP)956.6Macd transgenic mice also may be bred with other tTA transgenic strains for conditional mutation analysis.
