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Chromosome length and DNA loop size during early embryonic development of Xenopus laevis.
Micheli G
,
Luzzatto AR
,
Carrì MT
,
de Capoa A
,
Pelliccia F
.
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The looped organization of the eukaryotic genome mediated by a skeletal framework of non-histone proteins is conserved throughout the cell cycle. The radial loop/scaffold model envisages that the higher order architecture of metaphase chromosomes relies on an axial structure around which looped DNA domains are radially arranged through stable attachment sites. In this light we investigated the relationship between the looped organization and overall morphology of chromosomes. In developing Xenopus laevis embryos at gastrulation, the bulk of the loops associated with histone-depleted nuclei exhibit a significant size increase, as visualized by fluorescence microscopy of the fully extended DNA halo surrounding high salt treated, ethidium bromide stained nuclei. This implies a reduction in the number of looped domains anchored to the supporting nucleoskeletal structure. The cytological analysis of metaphase plates from acetic acid fixed whole embryos, carried out in the absence of drugs inducing chromosome condensation, reveals a progressive thickening and shortening of metaphase chromosomes during development. We interpret these findings as a strong indication that the size and number of DNA loops influence the thickness and length of the chromosomes, respectively. The quantitative analysis of chromosome length distributions at different developmental stages suggests that the shortening is timed differently in different embryonic cells.
Baumgartner,
Genes occupy a fixed and symmetrical position on sister chromatids.
1991, Pubmed
Baumgartner,
Genes occupy a fixed and symmetrical position on sister chromatids.
1991,
Pubmed
Blumenthal,
The units of DNA replication in Drosophila melanogaster chromosomes.
1974,
Pubmed
Boy de la Tour,
The metaphase scaffold is helically folded: sister chromatids have predominantly opposite helical handedness.
1988,
Pubmed
Briggs,
Genetics of cell type determination.
1979,
Pubmed
Buongiorno-Nardelli,
A relationship between replicon size and supercoiled loop domains in the eukaryotic genome.
1982,
Pubmed
,
Xenbase
Callan,
Replication of DNA in the chromosomes of eukaryotes.
1972,
Pubmed
Carrì,
The relationship between chromosomal origins of replication and the nuclear matrix during the cell cycle.
1986,
Pubmed
,
Xenbase
Cook,
Characterization of nuclear structures containing superhelical DNA.
1976,
Pubmed
Cook,
The nucleoskeleton and the topology of replication.
1991,
Pubmed
Cook,
Spectrofluorometric measurement of the binding of ethidium to superhelical DNA from cell nuclei.
1978,
Pubmed
Cook,
The nucleoskeleton and the topology of transcription.
1989,
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
Dijkwel,
Permanent attachment of replication origins to the nuclear matrix in BHK-cells.
1986,
Pubmed
Dingman,
Bidirectional chromosome replication: some topological considerations.
1974,
Pubmed
Earnshaw,
Mitotic chromosome structure.
1988,
Pubmed
Filipski,
Periodicity of DNA folding in higher order chromatin structures.
1990,
Pubmed
Gasser,
Replication origins, factors and attachment sites.
1991,
Pubmed
Gasser,
Studies on scaffold attachment sites and their relation to genome function.
1989,
Pubmed
Jack,
The elusive nuclear matrix.
1992,
Pubmed
Jackson,
The size of chromatin loops in HeLa cells.
1990,
Pubmed
Keppel,
Transcribed human ribosomal RNA genes are attached to the nuclear matrix.
1986,
Pubmed
King,
Prologue: nuclear transplantation in amphibia.
1979,
Pubmed
,
Xenbase
Laemmli,
Metaphase chromosome structure: the role of nonhistone proteins.
1978,
Pubmed
Laemmli,
Scaffold-associated regions: cis-acting determinants of chromatin structural loops and functional domains.
1992,
Pubmed
Lebkowski,
Evidence for two levels of DNA folding in histone-depleted HeLa interphase nuclei.
1982,
Pubmed
Marilley,
Supercoiled loop organization of genomic DNA: a close relationship between loop domains, expression units, and replicon organization in rDNA from Xenopus laevis.
1989,
Pubmed
,
Xenbase
Mikamo,
The mitotic chromosomes in Xenopus laevis (Daudin): normal, sex reversed and female WW.
1966,
Pubmed
,
Xenbase
Nelson,
The role of the nuclear matrix in the organization and function of DNA.
1986,
Pubmed
Newport,
A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage.
1982,
Pubmed
,
Xenbase
Newport,
A major developmental transition in early Xenopus embryos: II. Control of the onset of transcription.
1982,
Pubmed
,
Xenbase
Rattner,
Radial loops and helical coils coexist in metaphase chromosomes.
1985,
Pubmed
Razin,
The similarity of DNA sequences remaining bound to scaffold upon nuclease treatment of interphase nuclei and metaphase chromosomes.
1979,
Pubmed
Shiokawa,
Changes in the patterns of RNA synthesis in early embryogenesis of Xenopus laevis.
1989,
Pubmed
,
Xenbase
Shiokawa,
Temporal control of gene expression from endogenous and exogenously-introduced DNAs in early embryogenesis of Xenopus laevis.
1994,
Pubmed
,
Xenbase
Vogelstein,
Supercoiled loops and eucaryotic DNA replicaton.
1980,
Pubmed
Ward,
DNA loop domains in mammalian spermatozoa.
1989,
Pubmed
van der Velden,
Attachment of origins of replication to the nuclear matrix and the chromosomal scaffold.
1984,
Pubmed
