Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
???displayArticle.abstract???
We have analysed the replication of the chromosomal ribosomal DNA (rDNA) cluster in Xenopus embryos before the midblastula transition. Two-dimensional gel analysis showed that replication forks are associated with the nuclear matrix, as in differentiated cells, and gave no evidence for single-stranded replication intermediates (RIs). Bubbles, simple forks and double Ys were found in each restriction fragment analysed, showing that replication initiates and terminates without detectable sequence specificity. Quantification of the results and mathematical analysis showed that the average rDNA replicon replicates in 7.5 min and is 9-12 kbp in length. This time is close to the total S phase duration, and this replicon size is close to the maximum length of DNA which can be replicated from a single origin within this short S phase. We therefore infer that (i) most rDNA origins must be synchronously activated soon in S phase and (ii) origins must be evenly spaced, in order that no stretch of chromosomal DNA is left unreplicated at the end of S phase. Since origins are not specific sequences, it is suggested that this spatially and temporally concerted pattern of initiation matches some periodic chromatin folding, which itself need not rely on DNA sequence.
Adachi,
Identification of nuclear pre-replication centers poised for DNA synthesis in Xenopus egg extracts: immunolocalization study of replication protein A.
1992, Pubmed,
Xenbase
Adachi,
Identification of nuclear pre-replication centers poised for DNA synthesis in Xenopus egg extracts: immunolocalization study of replication protein A.
1992,
Pubmed
,
Xenbase
Bakken,
Mapping of transcription initiation and termination signals on Xenopus laevis ribosomal DNA.
1982,
Pubmed
,
Xenbase
Baldari,
Electron microscopic analysis of replicating DNA of sea urchin embryos.
1978,
Pubmed
Bell,
ATP-dependent recognition of eukaryotic origins of DNA replication by a multiprotein complex.
1992,
Pubmed
Bénard,
Mapping of a Physarum chromosomal origin of replication tightly linked to a developmentally-regulated profilin gene.
1992,
Pubmed
Benbow,
On the nature of origins of DNA replication in eukaryotes.
1992,
Pubmed
Berezney,
Nuclear protein matrix: association with newly synthesized DNA.
1975,
Pubmed
Blumenthal,
The units of DNA replication in Drosophila melanogaster chromosomes.
1974,
Pubmed
Botchan,
Restriction analysis of the nontranscribed spacers of Xenopus laevis ribosomal DNA.
1977,
Pubmed
,
Xenbase
Botchan,
A specific replication origin in the chromosomal rDNA of Lytechinus variegatus.
1982,
Pubmed
Bozzoni,
Replication of ribosomal DNA in Xenopus laevis.
1981,
Pubmed
,
Xenbase
Brewer,
The localization of replication origins on ARS plasmids in S. cerevisiae.
1987,
Pubmed
Brewer,
The arrest of replication forks in the rDNA of yeast occurs independently of transcription.
1992,
Pubmed
Brewer,
A replication fork barrier at the 3' end of yeast ribosomal RNA genes.
1988,
Pubmed
Buongiorno-Nardelli,
A relationship between replicon size and supercoiled loop domains in the eukaryotic genome.
1982,
Pubmed
,
Xenbase
Burhans,
Identification of an origin of bidirectional DNA replication in mammalian chromosomes.
1990,
Pubmed
Busby,
Fate of amplified nucleoli in Xenopus laevis embryos.
1982,
Pubmed
,
Xenbase
Caddle,
Analysis of the autonomous replication behavior in human cells of the dihydrofolate reductase putative chromosomal origin of replication.
1992,
Pubmed
Callan,
Replication of DNA in the chromosomes of eukaryotes.
1972,
Pubmed
Cook,
The nucleoskeleton and the topology of replication.
1991,
Pubmed
Cox,
DNA replication occurs at discrete sites in pseudonuclei assembled from purified DNA in vitro.
1991,
Pubmed
,
Xenbase
Delidakis,
Amplification enhancers and replication origins in the autosomal chorion gene cluster of Drosophila.
1989,
Pubmed
DePamphilis,
Origins of DNA replication in metazoan chromosomes.
1993,
Pubmed
Diffley,
Protein-DNA interactions at a yeast replication origin.
1992,
Pubmed
Dijkwel,
Initiation of DNA replication in the dihydrofolate reductase locus is confined to the early S period in CHO cells synchronized with the plant amino acid mimosine.
1992,
Pubmed
Dijkwel,
Mapping of replication initiation sites in mammalian genomes by two-dimensional gel analysis: stabilization and enrichment of replication intermediates by isolation on the nuclear matrix.
1991,
Pubmed
Fangman,
Activation of replication origins within yeast chromosomes.
1991,
Pubmed
Fangman,
A question of time: replication origins of eukaryotic chromosomes.
1992,
Pubmed
Gaudette,
Replication forks are underrepresented in chromosomal DNA of Xenopus laevis embryos.
1986,
Pubmed
,
Xenbase
Gurdon,
The use of Xenopus oocytes for the expression of cloned genes.
1983,
Pubmed
,
Xenbase
Hamlin,
Mammalian origins of replication.
1992,
Pubmed
Harland,
Regulated replication of DNA microinjected into eggs of Xenopus laevis.
1980,
Pubmed
,
Xenbase
Heck,
Multiple replication origins are used during Drosophila chorion gene amplification.
1990,
Pubmed
Heintz,
Transcription factors and the control of DNA replication.
1992,
Pubmed
Heintz,
Eukaryotic replication origins as promoters of bidirectional DNA synthesis.
1992,
Pubmed
Heinzel,
Autonomous DNA replication in human cells is affected by the size and the source of the DNA.
1991,
Pubmed
Hernández,
Conserved features in the mode of replication of eukaryotic ribosomal RNA genes.
1993,
Pubmed
Huberman,
On the mechanism of DNA replication in mammalian chromosomes.
1968,
Pubmed
Huberman,
The in vivo replication origin of the yeast 2 microns plasmid.
1987,
Pubmed
Hutchison,
Changes in the nuclear distribution of DNA polymerase alpha and PCNA/cyclin during the progress of the cell cycle, in a cell-free extract of Xenopus eggs.
1989,
Pubmed
,
Xenbase
Hyrien,
Plasmid replication in Xenopus eggs and egg extracts: a 2D gel electrophoretic analysis.
1992,
Pubmed
,
Xenbase
Jackson,
Structure-function relationships in eukaryotic nuclei.
1991,
Pubmed
Kill,
The timing of the formation and usage of replicase clusters in S-phase nuclei of human diploid fibroblasts.
1991,
Pubmed
,
Xenbase
Kobayashi,
Identification of a site required for DNA replication fork blocking activity in the rRNA gene cluster in Saccharomyces cerevisiae.
1992,
Pubmed
Krysan,
Replication initiates at multiple locations on an autonomously replicating plasmid in human cells.
1991,
Pubmed
Laskey,
Chromosome replication in early development of Xenopus laevis.
1985,
Pubmed
,
Xenbase
Leibovici,
Nuclear distribution of PCNA during embryonic development in Xenopus laevis: a reinvestigation of early cell cycles.
1992,
Pubmed
,
Xenbase
Linskens,
Organization of replication of ribosomal DNA in Saccharomyces cerevisiae.
1988,
Pubmed
Linskens,
The two faces of higher eukaryotic DNA replication origins.
1990,
Pubmed
Mahbubani,
DNA replication initiates at multiple sites on plasmid DNA in Xenopus egg extracts.
1992,
Pubmed
,
Xenbase
Martín-Parras,
Initiation of DNA replication in ColE1 plasmids containing multiple potential origins of replication.
1992,
Pubmed
McKnight,
Electron microscopic analysis of chromosome metabolism in the Drosophila melanogaster embryo.
1978,
Pubmed
Méchali,
Lack of specific sequence requirement for DNA replication in Xenopus eggs compared with high sequence specificity in yeast.
1984,
Pubmed
,
Xenbase
Micheli,
An electron microscope study of chromosomal DNA replication in different eukaryotic systems.
1982,
Pubmed
,
Xenbase
Mills,
Replication occurs at discrete foci spaced throughout nuclei replicating in vitro.
1989,
Pubmed
,
Xenbase
Mirkovitch,
Organization of the higher-order chromatin loop: specific DNA attachment sites on nuclear scaffold.
1984,
Pubmed
Montag,
Structural analysis of the mitotic cycle in pre-gastrula Xenopus embryos.
1988,
Pubmed
,
Xenbase
Müller,
Unusual stability of recombination intermediates made by Escherichia coli RecA protein.
1992,
Pubmed
Nakamura,
Structural organizations of replicon domains during DNA synthetic phase in the mammalian nucleus.
1986,
Pubmed
Nakayasu,
Mapping replicational sites in the eucaryotic cell nucleus.
1989,
Pubmed
Newport,
A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage.
1982,
Pubmed
,
Xenbase
Pardoll,
A fixed site of DNA replication in eucaryotic cells.
1980,
Pubmed
Reeder,
rRNA synthesis in the nucleolus.
1990,
Pubmed
Shinomiya,
Analysis of chromosomal replicons in early embryos of Drosophila melanogaster by two-dimensional gel electrophoresis.
1991,
Pubmed
Stinchcomb,
Isolation and characterisation of a yeast chromosomal replicator.
1979,
Pubmed
Tran,
The replication behavior of Saccharomyces cerevisiae DNA in human cells.
1993,
Pubmed
van der Velden,
The nuclear matrix--its role in the spatial organization and replication of eukaryotic DNA.
1987,
Pubmed
Van't Hof,
Single-stranded replication intermediates of ribosomal DNA replicons of pea.
1991,
Pubmed
Vassilev,
Mapping an origin of DNA replication at a single-copy locus in exponentially proliferating mammalian cells.
1990,
Pubmed
Vaughn,
Replication initiates in a broad zone in the amplified CHO dihydrofolate reductase domain.
1990,
Pubmed
Vaughn,
Replication forks are associated with the nuclear matrix.
1990,
Pubmed
Westermark,
The pathogenesis of maturity-onset diabetes mellitus: is there a link to islet amyloid polypeptide?
1988,
Pubmed
Zhu,
Identification and characterization of a complex chromosomal replication origin in Schizosaccharomyces pombe.
1992,
Pubmed
Zhu,
Localization of a DNA replication origin and termination zone on chromosome III of Saccharomyces cerevisiae.
1992,
Pubmed
