2°NC cells arise from the dorsal diencephalon and mesencephalon.

Wildtype embryos at 18 hpf were examined for the indicated combinations of diencephalic/mesencephalic marker genes by fluorescence double in situ hybridisation. Anterior top, dorsal views. The boundary between diencephalon (d) and mesencephalon (m) is indicated by a stippled horizontal line. (A-B) In dorsal views, both sox10 and sox9b appear co-expressed with pax6b that is expressed in the posterior diencephalon. However, co-localization analysis showed neither sox10- nor sox9b-positive cells co-express pax6b (A’ and B’). The posterior end of pax6b expression marks the boundary between diencephalon and mesencephalon (stippled line). (C, C’) sox9b-positive cells (magenta) in the diencephalon co-express the epiphysis marker gene, otx5 (green). Scale Bar: (A-C, A’-C’) 50 μm. (PDF)