Figure 2.

Role of NG2 in cell motility. Left, Oligodendrocyte progenitor motility. Oligodendrocyte progenitors prepared from neonatal wild type (wt) and NG2 knockout (ko) brains were grown as aggregates and then plated on surfaces coated with fibronectin (A and B) or type VI collagen (C–H). After 36 hours, cultures were labeled with A2B5 antibody to visualize progenitor migration away from the body of the aggregate. Although wild type and knockout progenitors migrate equally well on fibronectin-coated surfaces, NG2 null progenitors migrate much more poorly on collagen VI due to the absence of NG2. Right, Process extension by oligodendrocyte progenitors. Wild type (wt) and NG2 null (ko) oligodendrocyte progenitors were plated on type VI collagen coated surfaces. After 36 hours, cells were labeled with A2B5 antibody (top) or with NG2 antibody (bottom). Bottom panels confirm that NG2 is absent from NG2 null progenitors. Top panels show that processes of wild type progenitors are tipped by complex growth cone-like structures (arrows). These structures are absent from the processes of NG2 null progenitors. Growth cone-like structures may be important for mediating the motility of wild type progenitors on collagen VI, as seen in the left-hand panels.