Oct 20 2021

Colloquium- Prof. Mike Rust, University of Chicago

Physics Colloquium Lecture

October 20, 2021

3:00 PM - 4:00 PM


UIC Thomas Beckham Hall Classrooms, Room 180G


1218 S. Halsted St., 180G (Doors located next to Ghareeb Nawaz, NOT the doors next to Subway), Chicago, IL 60607

The Circadian Clock Ensures Successful DNA Replication in Cyanobacteria


Disruption of circadian rhythms causes decreased health and fitness, and evidence from multiple organisms links clock disruption to dysregulation of the cell cycle. However, the function of circadian regulation for the essential process of DNA replication remains elusive. Here we demonstrate that in the cyanobacterium Synechococcus elongatus, a model organism with the simplest known circadian oscillator, the clock generates rhythms in DNA replication to minimize the number of open replication forks near dusk that would have to complete after sunset. Metabolic rhythms generated by the clock ensure that resources are available early at night to support any remaining replication forks. Combining mathematical modeling and experiments, we show that metabolic defects caused by clock-environment misalignment result in premature replisome disassembly and replicative abortion in the dark, leaving cells with incomplete chromosomes that persist through the night. Our study thus suggests that a major function of this ancient clock is to safeguard the integrity of the genome.


Physics Office

Date posted

Sep 10, 2021

Date updated

Dec 8, 2021