Nutrient-specific effects in the coordination of cell growth with cell division in continuous cultures of Saccharomyces cerevisiae.

Cell cycle progression of Saccharomyces cerevisiae cells was monitored in continuous cultures limited for glucose or nitrogen. The G1 cell cycle phase, before initiation of DNA replication, did not exclusively expand when growth rate decreased. Especially during nitrogen limitation, non-G1 phases expanded almost as much as G1. In addition, cell size remained constant as a function of growth rate. These results contrast with current views that growth requirements are met before initiation of DNA replication, and suggest that distinct nutrient limitations differentially impinge on cell cycle progression.