Phospholipid biosynthesis during normal and dystrophic avian muscle cell differentiation in culture

The biosynthesis of phospholipids during differentiation of normal and dystrophic muscle cells was studied using [32Pi] added to primary culture media. Labeled phosphatides were separated by two-dimensional thin-layer chromatography, exposing the plates to HCl vapors between solvents to cleave the alk-1-enyl bonds. Phosphatidylethanolamine labeling did not vary during myotube formation. Although lower labeling of phosphatidylcholine was observed in dystrophic myoblasts at the single cell stage, no differences were observed between normal and dystrophic cultures after cell contact and myotube formation. A sharp decrease in phosphoinositide content was observed as myoblasts first achieved cell contact and continued to decline slowly as myotubes developed. During myogenesis, phosphatidylcholine content gradually increased, from 18.4% of the total labeled phospholipid in dividing myoblasts to 48.6% of the labeled phospholipids in fully differentiated myotubes.