Abstract
Striking changes in protein and RNA synthesis were shown to accompany development in the slime mould Dictyostelium discoideum. These changes are, at least in part, directly attributable to control at the level of transcription. Analysis of nuclear proteins and their states of phosphorylation by two-dimensional gel electrophoresis and autoradiography showed only minor changes in the species of proteins detectable by Coomassie Blue staining during the vegetative growth and development phases. Major changes, however, were detected in their patterns of phosphorylation, with major differences from the vegetative pattern occurring during both early development (0-2h) and late development (8-12h). These changes coincide with major changes in polypeptide synthesis and in nuclear and cytoplasmic RNA complexity.