Cellular quiescence: are controlling genes conserved?

The fission yeast Schizosaccharomyces pombe is an excellent model for cellular quiescence that can be achieved experimentally with nutritional limitations. The target of rapamycin complex (TORC) is known to be important for the transition between proliferation and quiescence from yeast to humans, and the recently identified TORC components, Tti1 and Tel2, might control all of the cellular phosphoinositide 3-kinase-related kinases. New pilot studies using deletion mutants and temperature-sensitive mutants suggest that up to approximately 1000 genes are required for quiescence, and approximately 300 of these, called superhousekeeping genes, also participate in proliferation. These latest findings suggest that genes controlling quiescence are conserved from yeast to humans, and support the use of S. pombe as a model to enhance our understanding of the causes of aging, diabetes, obesity and neurodegeneration.