Figure 5.

Maintenance of multipotency in NCSCs by combinatorial Wnt and BMP signaling. After emigration, eNCSCs (A) were exposed to Wnt1 and BMP2 and maintained for 5 d (B). Some cultures were incubated for an additional 7 d in the presence of Wnt1/BMP2 and continued to express the NCSC markers Sox10 and p75 (C). On sister plates, in the presence of Wnt1 alone, most of the cells maintain Sox10 expression (D) while sensory neurons expressing Brn-3A and NF are rarely found (E). However, NCSCs after prolonged exposure to Wnt1/BMP2 efficiently generate SMA-positive smooth muscle–like cells in the presence of TGFβ (F) and Sox10/GFAP-positive glia in the presence of NRG1 (G). In the absence of Wnt1, NCSCs express the autonomic marker Mash-1 in the presence of BMP2 (H). To challenge individual cells with instructive growth factors, NCSCs that have been maintained in the presence of Wnt1/BMP2 for 11 d were replated at clonal density (I) (Table I) or as cell clusters (M). In the presence of TGFβ, founder cells generate clones of smooth muscle–like cells (J), whereas NRG1 promotes gliogenesis (K). BMP2 induces a smooth muscle–like fate at clonal density (L) and autonomic neurogenesis in cell communities (N). Bars, 10 μm.