Macromolecular events following refeeding of starved Tetrahymena

Tetrahymena were starved in inorganic buffer for 24 h and then refed with enriched nutrient medium. An early increase of protein synthesis which is correlated with the rapid reformation of polysomes occurs prior to the onset of increased RNA synthesis. Inhibition of RNA synthesis with actinomycin D during refeeding did not stop the initiation of increased protein synthesis nor did it stop the reformation of polysomes. The occurrence of increased protein synthesis prior to increased RNA synthesis is a different sequence than has occurred in other studies on this cell and indicates that unlike in bacteria the macromolecular response of this cell to a new environment is not fixed but is dependent upon the cell's previous environmental history.