Electron spin resonance studies of the membranes of the cellular slime mold Dictyostelium discoideum

Doxylstearic acid spin labels are used to study the fluidity of the membranes of the cellular slime mold, Dictyostelium discoideum. The T₀ value of the wildtype cell membrane is close to that of egg lecithin indicating a rather fluid membrane. No detectable change in the fluidity of the bulk lipids at the 16-carbon depth occurs during differentiation of the myxamoebae into stalk and spore cells despite reported changes in the individual lipid components. The results of studies on temperature-sensitive and aggregationless mutants are also presented.