Detection of mRNAs correlated with proliferation of cells in suspension cultures of Catharanthus roseus

Gene expression correlated with proliferation was investigated in Catharanthus roseus (L.) G. Don. cells. Polyadenylated RNAs were isolated from cells in proliferative states or in nonproliferative states and the variations in the population and levels of mRNA were analyzed by in vitro translation followed by separation of the corresponding polypeptides by two-dimensional gel electrophoresis. Levels of two mRNAs increased in the actively cycling cells, while they were hardly detected in cells in stationary phase or in cells arrested by starvation of phosphate, sucrose or nitrogen. The molecular masses of the translated products of these two mRNAs were 53 and 60 kDa. No mRNAs were specifically synthesized in common among the various cultures of cells whose growth was arrested by nutrient starvation.