Balanced biosynthesis and trigger threshold resulting in a double adder mechanism of cell size control

Leilei Li

Figure 5. The division-centric picture and the replication-centric picture of the cell cycle. (a) In the division-centric picture, the cell cycle is separated into three periods. The first period is from cell birth to initiation of DNA replication, named B period. The second period is the time interval DNA replication occupies, called C period. The last one is from the completion of the chromosome of replication to cell division, named D period. DNA replication begins at the origin when the cell size reaches a critical volume Vi and ends at the terminus. (b) The replication-centric picture is defined as two consecutive chromosome replication initiations. It is worth noting that (b) is only tenable at a slow growth rate. When doubling time is shorter than C + D, there will be more than one round replication in the cell. All the biological variables are defined in table 2.