Effect of ploidy on the critical size for cell proliferation of the yeast Saccharomyces cerevisiae

For a polyploid series of Saccharomyces cerevisiae strains ranging from haploid to tetraploid we found that the critical cell size required to initiate a new cell division process was directly and linearly proportional to ploidy, but was not influenced by the information at the MAT locus which determines cell type. Therefore, over at least a four-fold range in ploidy the cell cycle machinery which is responsive to growth is modulated by nuclear DNA content.