Asynchronous Duplication of Chromosomes in Cultured Cells of Chinese Hamster

Jh, Taylor

doi:10.1083/jcb.7.3.455

Cited by 501 publications

(101 citation statements)

References 12 publications

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“…For example, it might be assumed that such a localized labelling represents late-replicating chromatin. However, it has been found (Taylor, 1960;Hsu, 1964;Deaven and Petersen," 1973;Cremer and Gray, 1982b) that, besides the sex chromosomes, chromosomes 10,11 contain large amounts of late-replicating material. Furthermore, in the CHL cells used here, no strong spatial association of these chromosomes was found (L. Hens et al, in preparation).…”

Section: Discussionmentioning

confidence: 99%

UV micro-irradiation of the Chinese hamster cell nucleus and caffeine post-treatment immunocytochemical localization of DNA photolesions in cells with partial and generalized chromosome shattering

Cremer

Hens³

et al. 1983

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

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SummaryUV micro-irradiation of a small part of the Chinese hamster nucleus and caffeine post-incubation often results in shattered chromosomes at the first post-irradiation mitosis. In some of these mitotic cells, chromosome shattering is restricted to a few chromosomes spatially related in a small area of the metaphase spread; in others, shattering includes the whole chromosome complement. These 2 types of damage have been called partial and generalized chromosome shattering (PCS and GCS).Using antisera that specifically react with UV-irradiated DNA, we identified micro-irradiated chromatin in interphase nuclei and in mitotic cells with PCS or GCS by indirect immunofluorescence microscopy. In PCS, immunofluorescence staining was found in the damaged area, while the surrounding intact chromosomes were not stained. In GCS, staining was also restricted to a small region of the shattered chromosome complement. In other experiments, cells synchronized in G 1 were micro-irradiated in the nucleus, pulse-labelled with [3H]thymidine and post-incubated with caffeine. Autoradiographs of cells with GCS showed unscheduled DNA synthesis restricted to a small chromatin region.Our data present direct evidence that the distribution of DNA photolesions does not coincide with the sites of chromosomal damage in GCS. As a working hypothe-0027-5107/83/0000-0000/$03.00

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Section: Discussionmentioning

confidence: 99%

UV micro-irradiation of the Chinese hamster cell nucleus and caffeine post-treatment immunocytochemical localization of DNA photolesions in cells with partial and generalized chromosome shattering

Cremer

Hens³

et al. 1983

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

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“…For comparison, measurements of chromosome 1 domain areas in female amniotic fluid cell nuclei (n = 48) yielded a mean ratio of 1.5 k 0.5 SD (larger domain area observed in each nucleus divided by the smaller domain area) (J. Schmidt and T. Cremer, unpublished data). As compared to the relative domain sizes of autosomes, additional variability in the relative sizes of Xa-and Xidomains can be expected in non-synchronized cultures due to the different replication timing of the active and inactive X-chromosome (Grumbach et al, 1963;Taylor, 1960). The fraction of S-phase nuclei was not determined in the subconfluent cultures used for the 2D and 3D analyses.…”

Section: Discussionmentioning

confidence: 99%

Differences of size and shape of active and inactive X‐chromosome domains in human amniotic fluid cell nuclei

Bischoff¹,

Albers

Kharboush

et al. 1993

Microscopy Res & Technique

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It is a widely held belief that the inactive X-chromosome (Xi) in female cell nuclei is strongly condensed as compared to the largely decondensed active X-chromosome (Xa). We have reconsidered this problem and painted X-chromosome domains in nuclei of subconfluent, female and male human amniotic fluid cell cultures (46,XX and 46,XY) by chromosomal in situ suppression (CISS) hybridization with biotinylated human X-chromosome specific library DNA. FITCconjugated avidin was used for probe detection and nuclei were counterstained with propidium iodide (PI). The shape of these nuclei resembling flat ellipsoids or elliptical cylinders makes them suitable for both two-dimensional (2D) and three-dimensional (3D) analyses. 2D analyses of Xi-and Xa-domains were performed in 34 female cell nuclei by outlining of the painted domains using a camera lucida. Identification of the sex chromatin body in DAPI-stained nuclei prior to CISShybridization was confirmed by its colocalization with one of the two painted X-domains. In 31 of the 34 nuclei the area Axi for the inactive X-domain was smaller than the area A, , for the active domain (mean ratio Ax,/Ax, = 1.9 * 0.8 SD, range 1.0-4.3). The signed rank test showed a highly significant (P < .0001) difference both between A, , and Axi and between the ratios r(Xa) and r(Xi), calculated by dividing the maximum length L of each X-domain by its maximum width W. In most nuclei (26134) we found r(Xa)>r(Xi) demonstrating a generally more elongated structure of Xa. For 3D analysis a confocal scanning laser fluorescence microscope (CSLFM) was used. Ten to 20 light optical sections (PI-image, FITC-image) were registered with equal spacings (approx. 0.4 pm). A thresholding procedure was applied to determine the PI-labeled nuclear and FITC-labeled X-domain areas in each section. Estimated slice volumes were used to compute total nuclear and X-domain volumes. In a series of 35 female nuclei most domains extended from the top to the bottom nuclear sections. The larger of the two X-chromosome domains comprised (3.7 t 1.7 S.D.)% of the nuclear volume. A mean ratio of 1.2 k 0.2 SD (range 1.1-2.3) was found for the volumes of the larger and the smaller X-domains in these female nuclei. In a series of 27 male amniotic fluid cell nuclei the relative X-chromosome domain volume comprised (4.0 t 2.6 S.D.)%. These findings indicate that differences in the 3D expansion of active and inactive X-chromosome domains are less pronounced than previously thought. A current model suggests that chromosome domains consist of a compact core surrounded by loosely coiled outer chromatin fiber loops. The latter fraction may be considerably larger in Xa-as compared to Xi-domains. We suggest that the interactive outlining procedure used in the 2D analyses included the loosely structured domain periphery more accurately, while the threshold algorithm applied to light optical sections delineated the more compact core of the domains, leading to smaller and more similar volume estimates of Xa and Xi. Present limitat...

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“…Certain properties of this inactivated chromosome, such as its late replication during the S-phase of mitosis (Taylor, 1960;Grumbach & Morishima, 1962;Mukherjee & Sinha, 1963), heteropyknosis during prophase and the formation of a sex chromatin body during interphase (Ohno, Kaplan & Kinosita, 1959;Ohno & Hauschka, 1960) have been used as criteria for establishing when the process ofinactivation begins. These features first appear in blastocysts at about the time of implantation in the cat (Austin & Amoroso, 1957), dog (Austin, 1966), rat (Zybina, 1960), hamster (Hill & Yunis, 1967), vole (Microtus agrestis) (Lee & Yunis, 1971), rhesus monkey (Macaca mulatta) (Park, 1957) and man (Glenister, 1956;Park, 1957).…”

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Sex Chromatin Formation in the Blastocyst of the Roe Deer (Capreolus Capreolus) During Delayed Implantation

Aitken¹

1974

Reproduction

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Asynchronous Duplication of Chromosomes in Cultured Cells of Chinese Hamster

Cited by 501 publications

References 12 publications

UV micro-irradiation of the Chinese hamster cell nucleus and caffeine post-treatment immunocytochemical localization of DNA photolesions in cells with partial and generalized chromosome shattering

UV micro-irradiation of the Chinese hamster cell nucleus and caffeine post-treatment immunocytochemical localization of DNA photolesions in cells with partial and generalized chromosome shattering

Differences of size and shape of active and inactive X‐chromosome domains in human amniotic fluid cell nuclei

Sex Chromatin Formation in the Blastocyst of the Roe Deer (Capreolus Capreolus) During Delayed Implantation

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