Fig. 4.

Clonal expansion of oligodendrocyte lineage cells is greater in low-density base cultures (A) than in high-density experimental cultures (B). E18 spinal cord cells were infected with BAG2 retrovirus at the time of plating. Two days later, A2B5-enriched cells were added to experimental cultures. After an additional 6 d in vitro, the size of clones of oligodendrocyte lineage cells was determined.A, B, Low-magnification micrograph of X-gal-stained oligodendrocyte lineage clones from base (A) and experimental (B) cultures. Note that there are far more cells in the base culture clone than in the experimental culture clone. Scale bar, 100 μm.