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Bacterial chromosomal loci move subdiffusively through a viscoelastic cytoplasm.

ABSTRACT: Tracking of fluorescently labeled chromosomal loci in live bacterial cells reveals a robust scaling of the mean square displacement (MSD) as ?(0.39). We propose that the observed motion arises from relaxation of the Rouse modes of the DNA polymer within the viscoelastic environment of the cytoplasm. The time-averaged and ensemble-averaged MSD of chromosomal loci exhibit ergodicity, and the velocity autocorrelation function is negative at short time lags. These observations are most consistent with fractional Langevin motion and rule out a continuous time random walk model as an explanation for anomalous motion in vivo.

SUBMITTER: Weber SC

PROVIDER: S-EPMC4929007 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature

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Bacterial chromosomal loci move subdiffusively through a viscoelastic cytoplasm.

Weber Stephanie C SC Spakowitz Andrew J AJ Theriot Julie A JA

Physical review letters 20100608 23

Tracking of fluorescently labeled chromosomal loci in live bacterial cells reveals a robust scaling of the mean square displacement (MSD) as τ(0.39). We propose that the observed motion arises from relaxation of the Rouse modes of the DNA polymer within the viscoelastic environment of the cytoplasm. The time-averaged and ensemble-averaged MSD of chromosomal loci exhibit ergodicity, and the velocity autocorrelation function is negative at short time lags. These observations are most consistent wi ...[more]

PMID: 20867274

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