Venus expression faithfully reflects endogenous Sox10 expression. Immunohistochemistry was used to confirm the in vivo co-localization of Venus with specific cell-type markers in Sox10- Venus mice. (A-F) All Sox10-positive cells were also positive for Venus; no ectopic Venus expression was detected in an entire series of sections. (A) In the E15.5 d alimentary tract, PGP9.5-positive enteric ganglion cells were also positive for Venus. (B) TH-positive endocrine cells in the E15.5 d adrenal gland were invariably positive for Venus. (C-D) While all Hu-positive early embryonic DRG neurons expressed endogenous Sox10 and Venus protein at E11.5 d, mature DRG neurons lost the Sox10 and Venus expression simultaneously at E15.5 d, and Sox10+ satellite cells became positive for Venus. (E-F) In the embryonic sympathetic ganglia, all the TH+ neurons were also Venus+ at E11.5 d, whereas TH+/Venus- cells appeared at E15.5 d. Hu+, terminally differentiated neuron; PGP9.5+, enteric ganglion cell; TH+, adrenal gland endocrine cells and sympathetic ganglion neurons; epi, epithelium. Scale bars (A-F) 50 μm.