Department of Biochemistry, Oxford University, London, UK.
The rum1+ gene is identified as a new regulator of G1 progression in fission yeast. It influences three aspects of G1 regulation: determination of the length of G1, dependence of S phase upon completion of mitosis, and restraint of mitosis until G1 is finished. We propose that it has a central role in regulating the G1 phase of the cell cycle.