Cancer Cell, Volume 14 Supplemental Data Article Acquisition of Granule Neuron Precursor Identity Is a Critical Determinant of Progenitor Cell Competence to Form Shh-Induced Medulloblastoma Ulrich Schüller, Vivi M. Heine, Junhao Mao, Alvin T. Kho, Allison K. Dillon, Young-Goo Han, Emmanuelle Huillard, Tao Sun, Azra H. Ligon, Ying Qian, Qiufu Ma, Arturo Alvarez-Buylla, Andrew P. McMahon, David H. Rowitch, and Keith L. Ligon Supplemental Experimental Procedures Transgenic Animals, Mouse Procedures, and Genotyping All mouse procedures were performed in accordance with National Research Council recommendations for the care and use of animals. In all experiments embryos were obtained from timed pregnancies, with plug detection date defined as E0.5. For all animals, genotyping was done by PCR analysis using genomic DNA from mouse tail biopsies. Primers have been previously published in the respective literature for each line. Cre expression was further verified by immunohistochemistry using anti-Cre antibodies (see below). The ROSA26-eYFP flox/flox (Gt(ROSA)26Sor tm1(EYFP)Cos /J), Z/EG flox/flox (Tg(CAG- Bgeo/GFP)21Lbe), SmoM2 flox/flox (Gt(ROSA)26Sor tm1(Smo/EYFP)Amc /J) and hGFAP-cre (FVB- Tg(GFAP-cre)25Mes/J) mouse lines were obtained from Jackson Laboratory (Bar Harbour, ME). The Gli1-creERT2 and Shh-creERT2 mouse lines have been previously described (Ahn and Joyner, 2005; Harfe et al., 2004) and were induced with Tamoxifen at postnatal day 10. Immunocompromised Icr-SCID mice (Model #ICRSC-M) were obtained from Taconic Inc. (Germantown, NY). Generation and characterization of CAGCAT-EGFP flox/flox and Math1-cre transgenic animals that carry bacteriophage P1 cre recombinase under control of a 1.4 kb upstream Math1 enhancer element have been previously described (Kawamoto et al., 2000; Schüller et al., 2007). The Tlx3-cre mouse line was generated by insertion of the cre recombinase cassette just following the Tlx3 start site within the first coding exon of the Tlx3 locus (Xu et al., 2008). Generation of Olig2-tva-cre Mice Olig2-tva-cre mice were constructed using a 3.1Kb Sac I fragment from the Olig2 locus as a 5’ arm and a 3.6Kb Sma I-EcoRV fragment for the 3’ arm of the targeting vector. The full-length coding region of TVA receptor was cloned in tandem with an IRES-cre PGK neo cassette to yield a bicistronic, targeted allele capable of expression of TVA and Cre from a single transcript. The targeting construct was electroporated into 129 ES cells and colonies selected for neomycin resistance resulting in a targeting frequency of 4%. Several lines were used to generate high