EMSA. EMSA was performed with a 32P end-labeled SOD3 probe containing the conserved Sox binding site. Proteins added are noted at the top. The upper arrowhead indicates the GST-SOX10 HMG/DNA probe complex, and the lower arrowhead indicates the free probe. For competition experiments, unlabeled wild type (WT) or mutated (MT) probes were added to the indicated excess levels.