Hemizygous mice are viable, fertile, normal in size, and do not display any gross physical or behavioral abnormalities. Cre activity is observed in parasagittal domains of the cerebellum beginning at embryonic day 17 (E17). At E19, low level expression is observed in the most rostral lobe of cerebellum and expression broadens until all Purkinje cells express the transgene in adult mice. When bred with any mouse containing a loxP-flanked sequence of interest, Cre-mediated recombination will result in deletion of the flanked genome. These transgenic mice may be useful in studies utilizing "Cre-lox" technology, specifically regarding the nervous system, development and patterning of cerebellum, and cerebellar hypotrophy converse of Lhermitte-Duclos. Important Note: These mice also carry a GFP transgene that co-integrated with the Tg(Pcp2-cre)1Amc transgene. As such, GFP expression is reported in the cerebellum. The Jackson Laboratory 2024, used with permission.