Tissue distribution of Sox10 mRNA. Total cellular RNA from the indicated rat tissues (A) or regions of adult rat brain (B) was analyzed for the expression of Sox10 mRNA by Northern blot. Filters were hybridized consecutively with probes specific for Sox10 (top panel) and GAPDH (bottom panel). The region designated midbrain in Bcontained thalamus, hypothalamus, superior and inferior colliculi, as well as surrounding regions. Hippocampus included fimbria and part of the corpus callosum. Negative tissues not shown inA included spleen, lung, and kidney. Identical results were obtained with mouse tissues.