![]()
|
|
||||||||
J. Biol. Chem., Vol. 276, Issue 39, 36639-36646, September 28, 2001
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
and
From the UMR147, Batiment Trouillet-Rossignol, Institut Curie/CNRS,
26 Rue d'Ulm, 75248 Paris, France
In mammalian cells, DNA replication proceeds
according to a precise temporal order during the S phase, but how this
program is controlled remains poorly understood. We analyzed the
replication-dependent bromodeoxyuridine banding of
chromosomes in Chinese hamster cells treated with the spindle poison
nocodazole. In these cells, nocodazole induces a transient mitotic
arrest, followed by DNA re-replication without intervening cell
division. Nuclear fragmentation is often observed in tetraploid
derivatives, and previous studies suggest that replication timing of
chromosomes could be affected when they are segregated into different
micronuclei. Here we show that the onset of replication is frequently
asynchronous on individual chromosomes during the re-replication
process. Moreover, fluorescence in situ hybridization
analysis revealed that replication synchrony is equally altered in
fragmented and non-fragmented nuclei, indicating that asynchronous
onset of replication is not dependent on physical separation of the
chromosomes into isolated compartments. We also show that the ordered
program of replication is always preserved along individual
chromosomes. Our results demonstrate that the onset of replication of
individual chromosomes in the same nuclear compartment can be uncoupled
from the time of S-phase entry and from the programmed replication of
chromosome sub-domains, revealing that multi-level controls contribute
to establish replication timing in mammalian cells.
Supported by grants from the Association pour la Recherche sur le
Cancer and the Fondation pour la Recherche Médicale.
§
To whom correspondence should be addressed. Tel.: 33 (0)1 42346725;
Fax: 33 (0)1 42346674; E-mail: Michelle.Debatisse@curie.fr.
This article has been cited by other articles:
![]() |
M. Kar, D. Ghosh, and J. Sengupta Histochemical and morphological examination of proliferation and apoptosis in human first trimester villous trophoblast Hum. Reprod., November 1, 2007; 22(11): 2814 - 2823. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |