Modeling the Cell Division Cycle

Abstract

The ability of an organism to reproduce and perpetuate its species is one of life’s defining attributes. As far as we know of all life forms on earth, the replication of a set of genetic information encoded in the DNA is absolutely required. Because of stringent requirements for faithful gene replication and the uncertainty in environmental conditions, the biological cell – with its semipermeable membrane delineating the DNA from the surroundings – is a structural necessity. In other words, the cell could be viewed as the unit of life. The cell division cycle, or „cell cycle” for short, is the process of replicating the genetic material as well as other cellular components. In this chapter, the reader is introduced to the current consensus view of the molecular machinery of the cell cycle. The emphasis is not on the details of the biochemistry, but rather on the dynamics arising from the topology of the network of molecular interactions. After a summary of the physiology of the cell cycle, the key regulatory molecules are introduced. Using basic chemical reaction kinetics, the rates of the steps in the mechanism can be written and a set of dynamical equations are established. A detailed discussion of the work on fission yeast by Novak et al. [1] is provided to illustrate the intricacies and problems in modeling the cell cycle. The more complex mammalian cell cycle is also discussed briefly to show the evolutionary conservation of molecular pathways essential in cell cycle regulation.