Plasma membrane phospholipid,cholesterol and fatty acyl composition of differentiated and undifferentiated L6 myoblasts

The lipid composition of plasma membranes isolated from differentialted and undifferentiated L₆ myoblasts has been compared. In general, the plasma membranes of differentiated L₆ myoblasts have a higher cholesterol to phospholipid molar ratio than plasma membranes of undifferentiated cells. Differentiated L₆ myoblasts have increased relative amounts of phosphatidylethanolamine and phosphatidylcholine in their plasma membrane and a decreased relative amount of sphingomyelin when compared with the plasma membranes of undifferentiated myoblasts. In addition, preliminary results show that differentiated L₆ myoblasts plasma membrane phospholipid shows differences in the fatty acyl composition, specifically there appears to be relatively more 17∶0 and 24∶1 and less 16∶1 and 18∶1 than in plasma membrane phospholipids of undifferentiated L₆ myoblasts. These observations indicate that significant changes in plasma membrane lipid composition occur during myoblast differentiation. The role that changes in lipid composition play in control of cellular differentiation, however, remains to be elucidated.