Rapid and sequential movement of individual chromosomal loci to specific subcellular locations during bacterial DNA replication
- Patrick H. Viollier*,
- Martin Thanbichler*,
- Patrick T. McGrath*,
- Lisandra West,
- Maliwan Meewan,
- Harley H. McAdams, and
- Lucy Shapiro†
- Department of Developmental Biology, Beckman Center, Stanford University School of Medicine, Stanford, CA 94305
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Contributed by Lucy Shapiro, April 13, 2004
Abstract
The chromosomal origin and terminus of replication are precisely localized in bacterial cells. We examined the cellular position of 112 individual loci that are dispersed over the circular Caulobacter crescentus chromosome and found that in living cells each locus has a specific subcellular address and that these loci are arrayed in linear order along the long axis of the cell. Time-lapse microscopy of the location of the chromosomal origin and 10 selected loci in the origin-proximal half of the chromosome showed that during DNA replication, as the replisome sequentially copies each locus, the newly replicated DNA segments are moved in chronological order to their final subcellular destination in the nascent half of the predivisional cell. Thus, the remarkable organization of the chromosome is being established while DNA replication is still in progress. The fact that the movement of these 10 loci is, like that of the origin, directed and rapid, and occurs at a similar rate, suggests that the same molecular machinery serves to partition and place many, if not most, chromosomal loci at defined subcellular sites.
Footnotes
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↵ † To whom correspondence should be addressed at: Department of Developmental Biology, Stanford University School of Medicine, Beckman Center, B300, Stanford, CA 94305. E-mail: shapiro{at}stanford.edu.
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↵ * P.H.V., M.T., and P.T.M. contributed equally to this work.
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Abbreviations: CFP, cyan fluorescent protein; YFP, yellow fluorescent protein; FISH, fluorescence in situ hybridization; FROS, fluorescent repressor-operator system; FM, fluorescence microscopy; IFM, immunofluorescence microscopy; LacI, lac repressor; TetR, tet repressor.
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See Commentary on page 9175.
- Copyright © 2004, The National Academy of Sciences
