Although bacteria can double much faster than 24 hours, some species are nevertheless capable of maintaining robust internal oscillations with a period close to 1 day. That is, coherent timing is maintained even though the vast majority of the biochemical components are replaced during one oscillator cycle. To study the principles underlying this ability to remember a slow phase during rapid growth, we have modified a reconstituted protein oscillator system to allow dilution and injection of new material, simulating growth. This system shows that as simulated doubling time decreases, oscillator frequency increases and a bifurcation occurs around an 8 hour doubling time that destroys oscillations. We then show that cells avoid this problem using a transcriptional circuit that concentrates new protein synthesis in specific oscillator phases. Though injection of new material perturbs the oscillator phase, this scheme allows advances and delays to balance, greatly extending the range of growth rates compatible with function. Unlike existing human-engineered biochemical oscillators, this natural bacteria oscillator uses an architecture that provides remarkable robustness to growth.
Liu et al. (2026) studied this question.