Stochastic nucleoid segregation dynamics as a source of the phenotypic variability in Escherichia coli

by Mr. Itay Gelber

at Biological and soft-matter physics

Tue, 07 Jun 2022, 14:00
Sacta-Rashi Building for Physics (54), room 207


Segregation of the replicating chromosome from a single to two nucleoid bodies is one of the major processes in growing bacterial cells. The segregation dynamics is tuned by intricate interactions with other cellular processes like growth and division, ensuring flexibility in a changing environment. We propose that the internal stochasticity of the segregation process may be a source of cell-to-cell phenotypic variability, in addition to the well-established gene expression noise and uneven partitioning of low copy number components. We compare dividing cell lineages with filamentous cells, where the lack of the diffusion barriers is expected to reduce the impact of other factors on the variability of nucleoid segregation dynamics. The nucleoid segregation was monitored using HU-eGFP and time-lapse microscopy in live E. coli cells grown in linear grooves. The main characteristics of the segregation process, namely, the synchrony of partitioning, rates of separation and final positions, as well as the variability of these characteristics were determined for dividing and filamentous lineages. Our findings indicate that the variability of the chromosome segregation dynamics is reduced upon removal of boundaries between nucleoids, while the remaining variability is essentially inherent to the nucleoid itself.

Created on 01-06-2022 by Feingold, Mario (mario)
Updaded on 01-06-2022 by Feingold, Mario (mario)