DNA Content and Size of Sex Chromatin Positive Female Nuclei During the Cell Cycle

1967 ◽  
Vol 6 (1) ◽  
pp. 1-19 ◽  
Author(s):  
H.P. Klinger ◽  
H.G. Schwarzacher ◽  
Jane Weiss
Keyword(s):  
Cell Cycle ◽  
Dna Content ◽  
Sex Chromatin

Proliferative behaviour of high-ploidy cells in two murine tumour lines

1993 ◽  
Vol 104 (1) ◽  
pp. 31-36 ◽  
Author(s):  
C. de la Hoz ◽  
A. Baroja
Keyword(s):  
Cell Cycle ◽  
Dna Content ◽  
Film Studies ◽  
Biological Significance ◽  
Time Lapse ◽  
Proliferative Potential ◽  
Malignant Tumours ◽  
B16f10 Melanoma ◽  
Murine Tumour ◽  
High Ploidy

The presence of high-ploidy cells in malignant tumours has long been documented. However, the biological significance of these cells is not known and there is a great deal of controversy over their proliferative potential. We have analysed the behaviour of these cells in two murine tumour lines, B16F10 melanoma and 3T3A31M angiosarcoma, determining their DNA content by microspectrophotometry and using time-lapse film studies. We have found a discrepancy between the presence of high-ploidy cells in metaphase and the absence of hyperploid telophases. High-ploidy metaphases may be aborted (mitotic polyploidization), prolonged in time or evolve in the form of multipolar, generally tripolar, mitoses. Our results suggest that high-ploidy cells are capable of proliferating, despite certain peculiarities in their cell cycle, and constitute a tumour subpopulation whose role in neoplasia merits further study.

Nuclear DNA content and minimum generation time in herbaceous plants

1972 ◽  
Vol 181 (1063) ◽  
pp. 109-135 ◽  
Keyword(s):  
Cell Cycle ◽  
Dna Content ◽  
Cycle Time ◽  
Generation Time ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Annual Species ◽  
Cell Cycle Time ◽  
Developmental Processes ◽  
The Mean

Many components of cell and nuclear size and mass are correlated with nuclear DNA content in plants, as also are the durations and rates of such developmental processes as mitosis and meiosis. It is suggested that the multiple effects of the mass of nuclear DNA which affect all cells and apply throughout the life of the plant can together determine the minimum generation time for each species. The durations of mitosis and of meiosis are both positively correlated with nuclear DNA content and, therefore, species with a short minimum generation time might be expected to have a shorter mean cell cycle time and mean meiotic duration, and a lower mean nuclear DNA content, than species with a long mean minimum generation time. In tests of this hypothesis, using data collated from the literature, it is shown that the mean cell cycle time and the mean meiotic duration in annual species is significantly shorter than in perennial species. Furthermore, the mean nuclear DNA content of annual species is significantly lower than for perennial species both in dicotyledons and monocotyledons. Ephemeral species have a significantly lower mean nuclear DNA content than annual species. Among perennial monocotyledons the mean nuclear DNA content of species which can complete a life cycle within one year (facultative perennials) is significantly lower than the mean nuclear DNA content of those which cannot (obligate perennials). However, the mean nuclear DNA content of facultative perennials does not differ significantly from the mean for annual species. It is suggested that the effects of nuclear DNA content on the duration of developmental processes are most obvious during its determinant stages, and that the largest effects of nuclear DNA mass are expressed at times when development is slowest, for instance, during meiosis or at low temperature. It has been suggested that DNA influences development in two ways, directly through its informational content, and indirectly by the physical-mechanical effects of its mass. The term 'nucleotype' is used to describe those conditions of the nucleus which effect the phenotype independently of the informational content of the DNA. It is suggested that cell cycle time, meiotic duration, and minimum generation time are determined by the nucleotype. In addition, it may be that satellite DNA is significant in its nucleotypic effects on developmental processes.

scholarly journals Human Parvovirus B19 Infection Causes Cell Cycle Arrest of Human Erythroid Progenitors at Late S Phase That Favors Viral DNA Replication

2013 ◽  
Vol 87 (23) ◽  
pp. 12766-12775 ◽  
Author(s):  
Yong Luo ◽  
Steve Kleiboeker ◽  
Xuefeng Deng ◽  
Jianming Qiu
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Content ◽  
Parvovirus B19 ◽  
S Phase ◽  
Human Parvovirus B19 ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Cycle Arrest ◽  
Cellular Dna

Human parvovirus B19 (B19V) infection has a unique tropism to human erythroid progenitor cells (EPCs) in human bone marrow and the fetal liver. It has been reported that both B19V infection and expression of the large nonstructural protein NS1 arrested EPCs at a cell cycle status with a 4 N DNA content, which was previously claimed to be “G2/M arrest.” However, a B19V mutant infectious DNA (M20mTAD2) replicated well in B19V-semipermissive UT7/Epo-S1 cells but did not induce G2/M arrest (S. Lou, Y. Luo, F. Cheng, Q. Huang, W. Shen, S. Kleiboeker, J. F. Tisdale, Z. Liu, and J. Qiu, J. Virol.86:10748–10758, 2012). To further characterize cell cycle arrest during B19V infection of EPCs, we analyzed the cell cycle change using 5-bromo-2′-deoxyuridine (BrdU) pulse-labeling and DAPI (4′,6-diamidino-2-phenylindole) staining, which precisely establishes the cell cycle pattern based on both cellular DNA replication and nuclear DNA content. We found that although both B19V NS1 transduction and infection immediately arrested cells at a status of 4 N DNA content, B19V-infected 4 N cells still incorporated BrdU, indicating active DNA synthesis. Notably, the BrdU incorporation was caused neither by viral DNA replication nor by cellular DNA repair that could be initiated by B19V infection-induced cellular DNA damage. Moreover, several S phase regulators were abundantly expressed and colocalized within the B19V replication centers. More importantly, replication of the B19V wild-type infectious DNA, as well as the M20mTAD2mutant, arrested cells at S phase. Taken together, our results confirmed that B19V infection triggers late S phase arrest, which presumably provides cellular S phase factors for viral DNA replication.

Alterations in the cell cycle of mouse cumulus granulosa cells during expansion and mucification in vivo and in vitro

1996 ◽  
Vol 8 (6) ◽  
pp. 935 ◽  
Author(s):  
AW Schuetz ◽  
DG Whittingham ◽  
R Snowden
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Granulosa Cells ◽  
Dna Content ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Ovarian Follicles ◽  
S Phase

The cell cycle characteristics of mouse cumulus granulosa cells were determined before, during and following their expansion and mucification in vivo and in vitro. Cumulus-oocyte complexes (COC) were recovered from ovarian follicles or oviducts of prepubertal mice previously injected with pregnant mare serum gonadotrophin (PMSG) or a mixture of PMSG and human chorionic gonadotrophin (PMSG+hCG) to synchronize follicle differentiation and ovulation. Cell cycle parameters were determined by monitoring DNA content of cumulus cell nuclei, collected under rigorously controlled conditions, by flow cytometry. The proportion of cumulus cells in three cell cycle-related populations (G0/G1; S; G2/M) was calculated before and after exposure to various experimental conditions in vivo or in vitro. About 30% of cumulus cells recovered from undifferentiated (compact) COC isolated 43-45 h after PMSG injections were in S phase and 63% were in G0/G1 (2C DNA content). Less than 10% of the cells were in the G2/M population. Cell cycle profiles of cumulus cells recovered from mucified COC (oviducal) after PMSG+hCG-induced ovulation varied markedly from those collected before hCG injection and were characterized by the relative absence of S-phase cells and an increased proportion of cells in G0/G1. Cell cycle profiles of cumulus cells collected from mucified COC recovered from mouse ovarian follicles before ovulation (9-10 h after hCG) were also characterized by loss of S-phase cells and an increased G0/G1 population. Results suggest that changes in cell cycle parameters in vivo are primarily mediated in response to physiological changes that occur in the intrafollicular environment initiated by the ovulatory stimulus. A similar lack of S-phase cells was observed in mucified cumulus cells collected 24 h after exposure in vitro of compact COC to dibutyryl cyclic adenosine monophosphate (DBcAMP), follicle-stimulating hormone or epidermal growth factor (EGF). Additionally, the proportion of cumulus cells in G2/M was enhanced in COC exposed to DBcAMP, suggesting that cell division was inhibited under these conditions. Thus, both the G1-->S-phase and G2-->M-phase transitions in the cell cycle appear to be amenable to physiological regulation. Time course studies revealed dose-dependent changes in morphology occurred within 6 h of exposure in vitro of COC to EGF or DBcAMP. Results suggest that the disappearance of the S-phase population is a consequence of a decline in the number of cells beginning DNA synthesis and exit of cells from the S phase following completion of DNA synthesis. Furthermore, loss of proliferative activity in cumulus cells appears to be closely associated with COC expansion and mucification, whether induced under physiological conditions in vivo or in response to a range of hormonal stimuli in vitro. The observations indicate that several signal-transducing pathways mediate changes in cell cycle parameters during cumulus cell differentiation.

scholarly journals A Survey of Essential Gene Function in the Yeast Cell Division Cycle

2006 ◽  
Vol 17 (11) ◽  
pp. 4736-4747 ◽  
Author(s):  
Lisa Yu ◽  
Lourdes Peña Castillo ◽  
Sanie Mnaimneh ◽  
Timothy R. Hughes ◽  
Grant W. Brown
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Yeast Cell ◽  
Dna Content ◽  
Cell Cycle Progression ◽  
Essential Gene ◽  
Nucleotide Metabolism ◽  
Cycle Progression ◽  
New Genes ◽  
Yeast Genes

Mutations impacting specific stages of cell growth and division have provided a foundation for dissecting mechanisms that underlie cell cycle progression. We have undertaken an objective examination of the yeast cell cycle through flow cytometric analysis of DNA content in TetO7promoter mutant strains representing 75% of all essential yeast genes. More than 65% of the strains displayed specific alterations in DNA content, suggesting that reduced function of an essential gene in most cases impairs progression through a specific stage of the cell cycle. Because of the large number of essential genes required for protein biosynthesis, G1 accumulation was the most common phenotype observed in our analysis. In contrast, relatively few mutants displayed S-phase delay, and most of these were defective in genes required for DNA replication or nucleotide metabolism. G2 accumulation appeared to arise from a variety of defects. In addition to providing a global view of the diversity of essential cellular processes that influence cell cycle progression, these data also provided predictions regarding the functions of individual genes: we identified four new genes involved in protein trafficking (NUS1, PHS1, PGA2, PGA3), and we found that CSE1 and SMC4 are important for DNA replication.

Comparative DNA cytometry of primary and recurrent soft tissue sarcomas.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e22516-e22516
Author(s):  
Irina Dashkova ◽  
Larisa N. Vashchenko ◽  
Oleg Ivanovich Kit ◽  
Inna A. Novikova ◽  
Ekaterina Komarova ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Soft Tissue ◽  
Dna Content ◽  
Soft Tissue Sarcomas ◽  
Literary Analysis ◽  
Proliferation Index ◽  
Cell Distribution ◽  
Dna Cytometry ◽  
Flow Cytofluorometry ◽  
M Phase

e22516 Background: Soft tissue sarcomas (STS) are aggressive tumors with a high degree of recurrence. Radical resection within healthy tissues allows to reduce the recurrence percentage to 25-30% without subsequent therapy. The literary analysis has shown that the study of various biological properties of primary and recurrentsoft tissue tumorsis being conducted. However, currently there is a lack of information to understand the reasons for STS recurrence. The goal of investigation was to reveal the distinctive features of the DNA content and cell distribution in the phases of the cell cycle of recurrent STS. Methods: DNA cytometry in the tumor tissue of 30 primary soft tissue sarcomas and 30 STS recurrences was carried out using the method of flow cytofluorometry. The tumor ploidy and cell distribution in the cell cycle phases were analyzed. Results: A number of differences in the DNA cytometric parameters of primary and recurrent STS have been revealed, they include: an increase in the proportion of aneuploid tumors in case of recurrence, the number of tumors with DNA index within the mitotic cycle, an increase in the proportion of cells in G2+M- phase of diploid and aneuploid tumors and a decrease in S- phase of aneuploid ones. It has been shown that with a G2 differentiation degree, the proportion of cells in G2+M, S- and proliferation index of recurrent STS is significantly lower than the primary parameters. An increase in the proportion of cells in G2+M- phase and a decrease in the rate of proliferation of recurrent STS, depending on the stage, are shown only in case of stage III. Conclusions: The revealed features of DNA content and cell cycle of tumor cells of soft tissue sarcomas will allow to approach to understanding of biological bases of recurrence of this malignant disease.

scholarly journals Simultaneous detection of cyclin B1, p105, and DNA content provides complete cell cycle phase fraction analysis of cells that endoreduplicate

Cytometry ◽  
1999 ◽  
Vol 35 (3) ◽  
pp. 274-283 ◽  
Author(s):  
R. Michael Sramkoski ◽  
Susan W. Wormsley ◽  
Wade E. Bolton ◽  
D.C. Crumpler ◽  
James W. Jacobberger
Keyword(s):  
Cell Cycle ◽  
Dna Content ◽  
Simultaneous Detection ◽  
Cyclin B1 ◽  
Cell Cycle Phase ◽  
Phase Fraction ◽  
Cycle Phase ◽  
Complete Cell

DNA content and expression of cell cycle proteins in caterpillar nuclei from fetal human cardiac myocytes

2002 ◽  
Vol 440 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Hernán García Rivello ◽  
Patricia Cabeza Meckert ◽  
Amelia Gallo ◽  
Luis Palacios ◽  
Rubén P. Laguens
Keyword(s):  
Cell Cycle ◽  
Cardiac Myocytes ◽  
Dna Content ◽  
Cell Cycle Proteins

Sex Chromatin, Nuclear Size and the Cell Cycle

1967 ◽  
Vol 6 (2) ◽  
pp. 120-144 ◽  
Author(s):  
D.E. Comings
Keyword(s):  
Cell Cycle ◽  
Nuclear Size ◽  
Sex Chromatin
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