Figure 3.

Wnt effects on stem cells. A, Explants of E10.5–E11.5 cortex were infected with control, Wnt 7a, or Wnt 7b virus. After 5–6 d, explants were dissociated and grown under conditions that generate neurospheres with the mitogen FGF2 (10 ng/ml) or EGF (1 ng/ml). Ten days later, the proportion of neurospheres derived from infected cells was compared. More primary neurospheres are generated from Wnt 7a- or Wnt 7b-infected cells than control infected cells. B, C, Primary neurospheres were passaged, and the proportion of infected cells that generated secondary and tertiary neurospheres was determined. Although Wnt 7a tended to increase secondary (B) and tertiary (C) neurospheres compared with control infected cultures, the differences were not significant. ^*p ≤ 0.04 relative to control virus; ^**p < 0.004 relative to control virus.