title: Escherichia coli with a linear genome.
abstract: Chromosomes in eukaryotes are linear, whereas those of most, but not all, prokaryotes are circular. To explore the effects of possessing a linear genome on prokaryotic cells, we linearized the Escherichia coli genome using the lysogenic lambda-like phage N15. Linear genome E. coli were viable and their genome structure was stable. There were no appreciable differences between cells with linear or circular genomes in growth rates, cell and nucleoid morphologies, genome-wide gene expression (with a few exceptions), and DNA gyrase- and topoisomerase IV-dependent growth. However, under dif-defective conditions, only cells with a circular genome developed an abnormal phenotype. Microscopy indicated that the ends of the linear genome, but not the circular genome, were separated and located at each end of a new-born cell. When tos - the cis-element required for linearization - was inserted into different chromosomal sites, those strains with the genome termini that were more remote from dif showed greater growth deficiencies.
authors.affiliation: National Institute for Basic Biology (NIBB), Nishigonaka 38, Myodaijicyo, Okazaki 444-8585, Japan.
authors.forename: Tailin
authors.initials: T
authors.lastname: Cui
authors.forename: Naoki
authors.initials: N
authors.lastname: Moro-oka
authors.forename: Katsufumi
authors.initials: K
authors.lastname: Ohsumi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kodama
authors.forename: Taku
authors.initials: T
authors.lastname: Ohshima
authors.forename: Naotake
authors.initials: N
authors.lastname: Ogasawara
authors.forename: Hirotada
authors.initials: H
authors.lastname: Mori
authors.forename: Barry
authors.initials: B
authors.lastname: Wanner
authors.forename: Hironori
authors.initials: H
authors.lastname: Niki
authors.forename: Takashi
authors.initials: T
authors.lastname: Horiuchi
mesh_terms: D049109:Cell Proliferation; D002876:Chromosomes, Bacterial / Q000737:chemistry*; D003090:Coliphages / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology* / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D016680:Genome, Bacterial / Q000235:genetics*; D046228:Microarray Analysis