Control of Bacillus subtilis Replication Initiation during Physiological Transitions and Perturbations

• Published in: mBio 2019-12, Vol.10 (6)
• Main Authors: Sauls, John T, Cox, Sarah E, Do, Quynh, Castillo, Victoria, Ghulam-Jelani, Zulfar, Jun, Suckjoon
• Format: Article
• Language: English
• Subjects: Bacillus subtilis - cytology; Bacillus subtilis - physiology; Bacterial Physiological Phenomena; Cell Cycle; Cell Division; cell size; DNA Replication; Escherichia coli - cytology; Escherichia coli - physiology; Molecular Biology and Physiology; replication initiation; Replication Origin; single cell
• ISSN: 2161-2129; 2150-7511
• DOI: 10.1128/mBio.02205-19

and are evolutionarily divergent model organisms whose analysis has enabled elucidation of fundamental differences between Gram-positive and Gram-negative bacteria, respectively. Despite their differences in cell cycle control at the molecular level, the two organisms follow the same phenomenological principle, known as the adder principle, for cell size homeostasis. We thus asked to what extent and share common physiological principles in coordinating growth and the cell cycle. We measured physiological parameters of under various steady-state growth conditions with and without translation inhibition at both the population and single-cell levels. These experiments revealed core physiological principles shared between and Specifically, both organisms maintain an invariant cell size per replication origin at initiation, under all steady-state conditions, and even during nutrient shifts at the single-cell level. Furthermore, the two organisms also inherit the same "hierarchy" of physiological parameters. On the basis of these findings, we suggest that the basic principles of coordination between growth and the cell cycle in bacteria may have been established early in evolutionary history. High-throughput, quantitative approaches have enabled the discovery of fundamental principles describing bacterial physiology. These principles provide a foundation for predicting the behavior of biological systems, a widely held aspiration. However, these approaches are often exclusively applied to the best-known model organism, In this report, we investigate to what extent quantitative principles discovered in Gram-negative are applicable to Gram-positive We found that these two extremely divergent bacterial species employ deeply similar strategies in order to coordinate growth, cell size, and the cell cycle. These similarities mean that the quantitative physiological principles described here can likely provide a beachhead for others who wish to understand additional, less-studied prokaryotes.