title: 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 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 with fractional Langevin motion and rule out a continuous time random walk model as an explanation for anomalous motion in vivo.
authors.affiliation: Department of Biochemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Weber
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Spakowitz
authors.forename: Julie A
authors.initials: JA
authors.lastname: Theriot
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D016934:Caulobacter / Q000166:cytology / Q000378:metabolism; D002470:Cell Survival; D002876:Chromosomes, Bacterial / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D004058:Diffusion; D004548:Elasticity; D004926:Escherichia coli / Q000166:cytology / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D056426:Genetic Loci; D007700:Kinetics; D008954:Models, Biological; D009068:Movement; D012329:RNA, Bacterial / Q000378:metabolism; D014783:Viscosity
chemical_list: D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D012329:RNA, Bacterial