The pronuclear injection (PI)-based targeted transgenesis (PITT) method allows thegeneration of targeted transgenic (Tg) mice wherein a single copy of a transgene isintegrated into the locus following PI. The locus allows unbiased ubiquitous expression of integratedtransgenes; however, it remains little known whether tissue-specific promoters retaintheir functional properties when placed at the locus. We evaluatedtissue-specific activity and reproducibility of exogenous tissue-specific promoterstargeted to the locus by generating Thy1-Dre/Dre reporter miceusing PITT and assessed spatial expression patterns of the transgenes. The promoter targeted to the locus appearedactive in virtually all Purkinje cells in the cerebellum and hippocampus. However, mosaicexpression of the transgene under the promoter was observed in manyother organs. This phenomenon was consistent in all the Tg lines generated by PITT,indicating a high degree of reproducibility for this experiment.
展开▼
