Figure 7.

Sox10 controls development of melanoblasts and expression of the trp-2 gene. (a–f) Transverse sections of wild-type (a,b), heterozygous (c,d), and homozygous (e,f) Sox10^lacZ mice at E12.5 on corresponding hindlimb levels. Embryos were hybridized with probes specific for c-kit (a,c,e; main panels), mi (a,c,e; insets), and trp-2 (b,d,f). (g) Melanoblasts positive for c-kit, mi, or trp-2 in wild-type (+/+, black), heterozygous (+/−, gray), and homozygous (−/−, white) Sox10-deficient mice at E12.5. The numbers of positive cells in wild-type mice identified by each marker were arbitrarily set to 100%. (h) Luciferase reporter assay determining the interaction of Sox10 and the trp-2 gene. Reporter genes were transfected into tet-on N2A cells. Luciferase was expressed under the control of the 3.7-kb trp-2 promoter (trp2luc), the P₀ promoter (P0luc), or the thymidine kinase promoter (TKluc) or were lacking a specific promoter (pGL2). Luciferase activity was measured before and after doxycycline treatment. Sox10-dependent promoter activation was expressed as the ratio between these two values. Bars represent the result from three independent transfections +/− S.E.M.