Development of Dictyostelium discoideum: A study by scanning electron microscopy

Abstract

Stages in the development of the cellular slime mould Dictyostelium discoideum have been examined by scanning electron microscopy using specimens prepared by freeze-drying, infiltration with polyethylene glycol or freezing. Formation of the slime sheath characteristic of D. discoideum was first observed early in aggregation and by the time discrete aggregates had formed, they were completely enveloped in the slime sheath. At the first finger-like stage, the slime sheath appeared to be thicker at the base than at the tip of the aggregate but such variations in thickness of the slime sheath could not be observed in the migrating pseudoplasmodium although it has previously been suggested that this may be important in controlling cell differentiation during this migratory stage.