FIG. 8.
Sp1 levels increase in primary oligodendrocytes as they differentiate. Equal numbers of primary rat oligodendrocytes were lysed, and the extracts were subjected to Western blotting for p27Kip1, Sp1, Sp3, or β-actin. Day 0 indicates cells that were growing in GM and that were lysed when the cells were transferred to DM. Day 1 indicates either growing cells (GM) or differentiating cells (DM) 1 day after the medium was changed. The molecular masses of the two species of Sp3 detected are indicated.