The transgene comprises a 6-kb mouse genomic DNA fragment containing exons 1-8 of the gamma-aminobutyric acid type A receptor 6 (Gabra6) gene followed by an internal ribosomal entry site (IRES) and the full-length, 3.1-kb mouse Bmi1 polycomb ring finger oncogene (Bmi1) cDNA. Two (of four generated) transgenic lines, designated T3 and T4, overexpressed Bmi1 mRNA, as determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis, and BMI1 protein, as quantified by immunoblot analysis, in the cerebellum at both postnatal days (P) 9 and P15; the protein was localized to the internal granule cell layer by immunohistochemical labeling of the cerebella of nine-day old mice. (J:193730)