The budding yeast, Saccharomyces cerevisiae, divides by shedding buds. The resulting daughter cell is smaller and has a longer cell cycle than the mother cell. The mother cell gets bigger and gives birth to larger daughter cells after each successive division. Bud formation and the length of the budded period are size dependent. In this paper a deterministic model for the biochemical architecture of the budding yeast cell cycle is taken to the population level. Without adding any stochastic process either in the cell cycle itself or at the moment of cell separation, the population reaches stable size distributions. Size distributions do occur in this model because the response to size is not the same for all cells (i.e., not characterized by size alone). The shape of the theoretical distributions is similar to those observed in experiments, but the width of the theoretical distributions is two-fold smaller.
Keywords: budding yeast, cell cycle, population dynamics, biochemical model.
John Val
- John J. Tyson 
Department of Biology, Virginia Polytechnic Institute
and State University, Blacksburg, Virginia 24060-0406, USA.
email:1) John 2) tyson@vtvm1.cc.vt.edu
April 26, 1996