Bacterial Size: Can’t Escape the Long Arm of the Law Stephen Vadia, Petra Anne Levin  Current Biology  Volume 27, Issue 9, Pages R339-R341 (May 2017) DOI: 10.1016/j.cub.2017.03.050 Copyright © 2017 Elsevier Ltd Terms and Conditions

Figure 1 The general growth law predicts absolute cell size under steady-state growth from just three variables. (A) Cell size can be predicted if the values of the unit cell (equal to initiation mass; S0), length of the DNA replication and division cycles, and the mass doubling time are known. The general growth law accurately predicts absolute cell sizes that deviate from the predictions of the nutrient growth law. The blue line illustrates the general relationship between cell size and growth rate as predicted by the nutrient growth law. The red lines indicate changes in size following delays in the timing and/or rate of cell-cycle progression (initiation of DNA replication, replication fork elongation, or cell division) without affecting growth. Inhibition of cell-cycle parameters alters the balance between cell-cycle progression and cell growth, leading to deviations in size from values that are predicted from growth rate alone. Yellow circles within nucleoids indicate origins of replication. (B) The bacterial cell cycle is commonly divided into three stages: birth to initiation of DNA replication (referred to here as S0); replication and segregation of the chromosome; and cell division (referred to together as τcyc). τ = the mass doubling time. Current Biology 2017 27, R339-R341DOI: (10.1016/j.cub.2017.03.050) Copyright © 2017 Elsevier Ltd Terms and Conditions