Inducible gene expression in postmitotic neurons by an in vivo electroporation-based tetracycline system

In vivo electroporation has been widely used to transfect foreign genes into neural progenitors and analyze the function of genes of interest in the developing nervous system. However, it has not been thoroughly examined in the conditional regulation of exogenous genes in postmitotic neurons. Here we show that the combination of in vivo electroporation and the newest version of the tetracycline (Tet)-controlled gene regulatory (Tet-On) system efficiently induced gene expression in various types of neurons in mouse embryonic and postnatal tissues. In pyramidal neurons of the cerebral cortex, tetracycline-responsive element (TRE)-driven gene expression was induced in the presence of doxycycline (Dox). The induction occurred in a dose-dependent manner. The Dox-dependent induction was also observed in cerebellar Purkinje cells and spinal cord neurons. Moreover, the TRE-driven inducible expression of mammalian Barh1 (Mbh1) mimicked the phenotype of the ubiquitous expression of Mbh1 in the spinal cord. These results indicate that the combination of the Tet-On system and in vivo electroporation is useful for analyzing gene function specifically in postmitotic neurons.