GLYCEROPHOSPHORYLCHOLINE PHOSPHOCHOLINE PHOSPHODIESTERASE ACTIVITY DURING THE DIFFERENTIATION OF GLIAL PROGENITOR CELLS

O-2A progenitor cells were grown in medium containing either 1% or 10% fetal calf serum (FCS) for 4 weeks. The cells in 1% FCS were 75% olig ondendrocytes by 3 weeks in culture. The cell population was so overgr own with astrocytes in the 10% medium that an accurate estimate of cel l number could not be made. The activities of glycerophosphorylcholine phosphocholine phosphodiesterase (GPC-PC-PdE), p-nitrophenylphosphory lcholine phosphodiesterase (pNPPC-PC-PdE), and ceramide UDP galactose galactosyl transferase (CGalT) were barely detectable in the cells gro wn in 10% FCS. The activities of these 3 enzymes were low in the cells grown in 1% FCS for the first 2 weeks and then all 3 increased manyfo ld. These observations reinforce the evidence previously accrued showi ng that these two phosphodiesterase activities (GPC-PC-PdE and pNPPC-P C-PdE) are markers of oligodendroglial cells as well as myelin. In con trast, glycerophosphorylcholine choline phosphodiesterase (GPC-C-PdE) activities were present in cells grown in both 1% and 10% FCS. (C) 199 3 Wiley-Liss, Inc.