Microcysts of the cellular slime mold Polysphondylium pallidum. II. Chemistry of the microcyst walls.

Methods are described for obtaining large masses of myxamoebae, for inducing these to form microcysts, and for the isolation of the microcyst walls from other cell components. The walls were fractionated into two parts, one alkali-soluble, the other alkali insoluble. The alkali-insoluble fraction is a type of cellulose and constitutes 28% of the microcyst wall by weight. The alkali-soluble fraction contains a glycogenlike material, lipids, and proteins. A possible mechanism of microcyst wall synthesis is discussed.