The chromosome fiber: Evidence for an ordered superstructure of nucleosomes

Hozier, John; Renz, Manfred; Nehls, Peter

doi:10.1007/bf00327030

Cited by 138 publications

(62 citation statements)

References 39 publications

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“…First, the total length of the DNA molecules which have to be compacted within a diploid mammalian nucleus of some 10 to 20 pm diameter is roughly 2 x 106 gm. Even when this DNA is packed to a thick chromatin fiber (Finch and Klug 1976;Hozier et al 1977) assuming a packaging factor of 25 to 40-fold each individual chromosome is composed of a chromatin fiber of several hundred to several thousand gm. Obviously, models ranging from very compact interphase chromosome domains to a dispersed arrangement of individual chromosomes throughout the whole interphase nucleus (e.g.…”

Section: Introductionmentioning

confidence: 99%

Specific staining of human chromosomes in Chinese hamster x man hybrid cell lines demonstrates interphase chromosome territories

Schardin¹,

Cremer²,

Hager³

et al. 1985

Hum Genet

222

132

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Summary. In spite of Carl Rabl's (1885) and Theodor Boveri's (1909) early hypothesis that chromosomes occupy discrete territories or domains within the interphase nucleus, evidence in favor pf this hypothesis has been limited and indirect so far in higher plants and animals. The alternative possibility that the chromatin fiber of single chromosomes might be extended throughout the major part of even the whole interphase nucleus has been considered for many years. In the latter case, chromosomes would only exist as discrete chromatin bodies during mitosis but not during interphase. Both possibilities are compatible with Boveri's well established paradigm of chromosome individuality. Here we show that an active human X chromosome contained as the only human chromosome in a Chinese hamster x man hybrid cell line can be visualized both in metaphse plates and in interphase nuclei after in situ hybridization with either 3H-or biotin-labeled human genomic DNA. We demonstrate that this chromosome is organized as a distinct chromatin body throughout interphase. In addition, evidence for the territorial organization of human chromosomes is also presented for another hybrid cell line containing several autosomes and the human X chromosome. These findings are discussed in the context of our present knowledge of the organization and topography of interphase chromosomes. General applications of a strategy aimed at specific staining of individual chromosomes in experimental and clinical cytogenetics are briefly considered.

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Section: Introductionmentioning

confidence: 99%

Specific staining of human chromosomes in Chinese hamster x man hybrid cell lines demonstrates interphase chromosome territories

Schardin¹,

Cremer²,

Hager³

et al. 1985

Hum Genet

222

132

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“…Staphylococcal nuclease digests bulk chromatin in five stages (5). The first stage is cleavage between groups of about eight nucleosomes (6)(7)(8). The second stage involves preferential cleavage between nucleosomes to produce an oligomeric series of particles from which an oligomeric series of DNA molecules can be extracted.…”

Section: Introductionmentioning

confidence: 99%

DNase I sensitivity of ribosomal genes in isolated nucleosome core particles

Giri¹,

Gorovsky²

1980

Nucl Acids Res

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The level of chromatin structure at which DNase I recognizes conformationial differences between inert and activated genes has been investigated. Bulk and ribosomal DNA's of Tetrahymena pyriformis were differentially labeled in vivo with [14C]-and [5H]-thymidineI respectively, utilizing a defined starvation-refeeding protocol. The H-labeled ribosomal genes were shown to be preferentially digested by DNase I in isolated nuclei. Staphylococcal nuclease digested the ribosomal genes more slowly than bulk DNA, probably owing to the higher GC content of rDNA. DNase I and staphylococcal nuclease digestions of purified nucleosomes and of nucleosome core particles isolated from dual-labeled, starved-refed nuclei were indistinguishable from those of intact nuclei. We conclude from these studies that DNase I recognizes an alteration in the internal nucleosome core structure of activated ribosomal genes.

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“…At low ionic strength the nucleofilament with diameter of 100 A is a single chain of nucleosomes (4)(5)(6)(7). In the presence of monovalent and divalent cations, the diameter of the nucleofilament is increased to 250400 A (4, 5, 7).…”

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mentioning

confidence: 99%

“…(7) have postulated that chromatin is organized into superbeads containing six to ten nucleosomes. However, ambiguity about these structures still remains since Hozier et al (7) were unable to isolate and resolve them on sucrose gradients. In kinetic studies performed in the work below, it has clearly been shown that micrococcal nuclease cleaves HeLa chromatin at a periodicity of eight nucleosomes.…”

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confidence: 99%

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Nucleosome periodicity in HeLa cell chromatin as probed by micrococcal nuclease.

Butt¹,

Jump²,

Smulson³

1979

Proc. Natl. Acad. Sci. U.S.A.

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When HeLa cell nuclei were treated with micrococcal nuclease (nucleate 3-oligonucleotidohydrolase, EC 3.1.4.7), lysed, and centrifuged, the supernatant from early digests contained two predominant classes of polynucleosomes of repeat size 8N and 16N. With increasing digestion time, the 16N polynucleosome appeared to be cleaved to the 8N species and finally to the basic subunit of chromatin. The size of the polynucleosomes has been determined by DNA analysis and on polyacrylamide electrophoretic gels of native chromatin particles. Thel6Npolynucleosome appears to be a unique higher ordered structural component of HeLa cell chromatin. Our recent report, showing that the nuclear protein-modifying enzyme poly(ADP-ribose) polymerase increases in specific activity progressively with increasing nucleosome repeat size up to 8-1ON, has been extended in the present study. Activity was also elevated in the polynucleosomes of the 16N structure preferentially cleaved by micrococcal nuclease, although specific activity of the enzyme was highest in octanucleosomes. Acceptors for poly(ADP-ribose) have also been determined in these particles.Despite recent advancement in our understanding of the structure of the nucleosome core particle, similar information concerning the higher order structure of chromatin remains largely undetermined (1)(2)(3). At low ionic strength the nucleofilament with diameter of 100 A is a single chain of nucleosomes (4-7). In the presence of monovalent and divalent cations, the diameter of the nucleofilament is increased to 250400 A (4, 5, 7). Based on electron micrographic data, Finch and Klug (4) postulated a solenoid model of chromatin.Kinetic studies performed on the action of micrococcal nuclease (nucleate 3'-oligonucleotidohydrolase, EC 3.1.4.7) on interphase chromatin and metaphase chromosomes (8-10) have supported the theory of random cleavage by the enzyme at uniformly susceptible sites on linker regions of polynucleosomes. However, it has also been shown that newly replicated chromatin is relatively more susceptible to the action of micrococcal nuclease (11).Using electron microscopic studies and sedimentation analysis on the chromatin produced after the digestion of lymphocyte nuclei by micrococcal nuclease, Hozier et al. (7) have postulated that chromatin is organized into superbeads containing six to ten nucleosomes. However, ambiguity about these structures still remains since Hozier et al. (7) were unable to isolate and resolve them on sucrose gradients. In kinetic studies performed in the work below, it has clearly been shown that micrococcal nuclease cleaves HeLa chromatin at a periodicity of eight nucleosomes. In addition to sedimentation analysis, we have been able to characterize these structures by (i) native chromatin gels, (ai) determination of the size of the DNA, and (Mi) the presence of a full complement of nuclear histones.These observations on nucleosome periodicity stemmed directly from our previous observation that the specific activity of a chromatin-bound enzyme, ...

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The chromosome fiber: Evidence for an ordered superstructure of nucleosomes

Cited by 138 publications

References 39 publications

Specific staining of human chromosomes in Chinese hamster x man hybrid cell lines demonstrates interphase chromosome territories

Specific staining of human chromosomes in Chinese hamster x man hybrid cell lines demonstrates interphase chromosome territories

DNase I sensitivity of ribosomal genes in isolated nucleosome core particles

Nucleosome periodicity in HeLa cell chromatin as probed by micrococcal nuclease.

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