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キーワード:
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要旨:
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.
