P19 cells were cultured as described in (Farah et al., 2000). Experimental conditions were tested in triplicate by transfection of cells in 12-well plates using Fugene 6 (Roche). Cotransfection of a Renilla luciferase expression construct was used as a normalization control for a dual-luciferase assay. The following amounts of DNA were used in each well: 80ng pGL4.73 (Renilla Luciferase, Promega), 240 ng pCAGGs-empty or pCAGGS-Dlx2, 240ng pGL4.23-empty (Luciferase, Promega) or pGL4.23-enhancer. Luciferase and Renilla Luciferase quantification was done using a Promega Dual-Lucifase Assay Kit and a microplate luminometer (Veritas). Chi-square test showed that the levels of activation were significant *: p<0.05.
