scholarly journals Pattern of DNA increase in macronuclear anlagen of Tetrahymena

1986 ◽  
Vol 83 (1) ◽  
pp. 155-164
Author(s):  
J. Roth ◽  
G. Cleffmann
Keyword(s):  
Cell Cycle ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
S Phase ◽  
The Mean

By combining cytophotometry with autoradiography, five stages of macronuclear anlagen can be discriminated by their DNA content until the end of the first cell cycle after conjugation in Tetrahymena. DNA increases from 2C to about 32C. Each S-phase is followed by a non-synthetic period. Comparing the mean nuclear DNA content after and before each S-phase revealed that 16C anlagen contain significantly less DNA than twice the amount of 8C anlagen. This is unlike the situation in other S-phases during which the amount of DNA is precisely doubled. In the second cell cycle after conjugation some of the cells increase their macronuclear G2 DNA content beyond the 64C stage, while the majority show a mean G2 content of about 64C.

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 The Complex Cell Cycle of the Dinoflagellate Protoctist Crypthecodinium Cohnii as Studied In Vivo and by Cytofluorimetry

1991 ◽  
Vol 100 (3) ◽  
pp. 675-682 ◽  
Author(s):  
YVONNE BHAUD ◽  
JEAN-MARIE SALMON ◽  
MARIE-ODILE SOYER-GOBILLARD
Keyword(s):  
Cell Cycle ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
S Phase ◽  
Vegetative Cells ◽  
Crypthecodinium Cohnii ◽  
Daughter Cells ◽  
The Times

The complete cell cycle of the dinoflagellate Crypthecodinium cohnii Biecheler 1938 was observed in vivo in a synchronized heterogeneous population, after DAPI staining of DNA. In a given population, the relative nuclear DNA content in each class of cell was measured using a new numerical image-analysis method that takes into account the total fluorescence intensity (FI), area (A) and shape factor (SF). The visible degree of synchronization of the population was determined from the number of cells with a nuclear content of 1C DNA at ‘synchronization’, time 0. One method of synchronization (method 1), based on the adhesiveness of the cysts, gave no better than 50% synchronization of the population; method 2, based on swimming cells released from cysts cultured on solid medium, gave 73% of cells with the same nuclear DNA content. A scatter plot of data for FI versus A in the first few hours after time 0 showed that the actual degree of synchronization of the population was lower. The length of the C. cohnii cell cycle determined in vivo by light microscopy was 10, 16 or 24 h for vegetative cells giving two, four or eight daughter cells, respectively. Histograms based on the FI measurements showed that in an initially synchronized population observed for 20 h, the times for the first cell cycle were: G1 phase, 6 h; S phase, 1 h 30 min; G2+M, 1h 30 min, with the release of vegetative cells occurring 1 or 2h after the end of cytokinesis. The times for the second cell cycle were G1+S, 3h; G2+M, 2h. FI and A taken together, suggested that the S phase is clearly restricted, as in higher eukaryotes. A and SF, taken together, showed that the large nuclear areas were always in cysts with two or four daughter cells. FI and SF, taken together, showed that the second S phase always occurred after completion of the first nuclear division. Our data concerning the course of the cell cycle in C. cohnii are compared with those from earlier studies, and the control of the number of daughter cells is discussed; this does not depend on the ploidy of the mother cell.

scholarly journals IMAGE ANALYSIS OF CHROMATIN IN CELLS OF PREIMPLANTATION MOUSE EMBRYOS

1974 ◽  
Vol 63 (1) ◽  
pp. 227-233 ◽  
Author(s):  
Wojciech Sawicki ◽  
Jan Rowínski ◽  
Jan Abramczuk
Keyword(s):  
Cell Cycle ◽  
Image Analysis ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Mouse Embryos ◽  
Stage Of Development ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
The Mean

Mouse two-celled embryos and blastulae were Feulgen stained and the DNA content of their nuclei was measured with an integrating microdensitometer. The cells considered on the basis of their nuclear DNA content to be in G1, S, and G2 phases of the cell cycle were selected and their total chromatin area and chromatin areas at different gray levels were measured by the image analyzing computer, Quantimet. The measurements were aimed at quantitation of several features of the chromatin morphology of cells in different functional states. The total area of chromatin was found to increase, and the mean density of chromatin to decrease, from the G1 to the G2 phase of the cell cycle in both two-celled embryos and blastulae. The area of chromatin decreased, and the mean density of chromatin increased, as embryos developed from two-celled to blastula stage. It was concluded that nuclear morphology in preimplantation mouse embryos depends on both the phase of the cell cycle and the stage of development. The method of image analysis described was found to be useful for quantitation of changes in chromatin morphology.

scholarly journals Relationship between nuclear DNA-content of sperm cells and the timing of events in the cell cycle of Brassica campestris L. (Brassicaceae)

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Hua Deng
Keyword(s):  
Cell Cycle ◽  
Quantitative Analysis ◽  
Dna Content ◽  
Nuclear Dna ◽  
Brassica Campestris ◽  
Nuclear Dna Content ◽  
Pollen Grain ◽  
S Phase ◽  
Sperm Cells ◽  
Generative Cells

In this work we conducted a quantitative analysis of the nuclear DNA-content of developing sperm cells of the plant <em>Brassica campestris</em> L. The sperm cells were in young pollen grain, mature pollen grain and pollen tubes. When generative cells, at the pre-anthesis stage, split into two sperm cells, we have established that the newly-formed sperm cells begin to synthesize nuclear DNA in developing pollen grain of <em>B. campestris</em>. We measured this DNA-content during the development of sperm cells. The results indicate that during development, sperm cells of <em>B. campestris</em> have passed the G<sub>1</sub> phase of the cell cycle and entered the S phase, presumably then fusing with egg cells at a level of 2C, as is characteristic of G<sub>2</sub> type fertilization in angiosperms.

Impact d'un traitement par le cycloheximide sur la reprise du cycle et sur les teneurs en protéines du bourgeon cotylédonaire du Pois réactivé par décapitation

1990 ◽  
Vol 68 (2) ◽  
pp. 420-427 ◽  
Author(s):  
Arlette Nougarède ◽  
Pierre Rondet ◽  
Pierre Landré ◽  
Robert Saint-Côme
Keyword(s):  
Protein Content ◽  
Mitotic Activity ◽  
Dna Content ◽  
Nuclear Protein ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
S Phase ◽  
Cytoplasmic Protein ◽  
The Mean ◽  
Low Amplitude

Following ablation of the main stem (decapitation), the mean nuclear protein content of the Pisum cotyledonary bud apical cells increased 35% as early as the 6th hour, just when a massive entry into the S phase was registered, and reached a maximum, with a 157% increase, at the 39th hour, when the mitotic activity was also at its highest. The ratio nuclear protein/nuclear DNA content was then multiplied by 1.8 in comparison with the ratio observed in the G0–1 noncycling nuclei of the inhibited cotyledonary bud. In the bud treated with cycloheximide, the mean nuclear protein content slowly increased following decapitation, but remained greatly inferior to that of the controls. A slight entry into the S phase was noticed at the 24th hour and the mean nuclear protein content, then maximal, increased 32% in comparison with the inhibited buds. In the control buds, the mean protoplasmic proteins content increased 116% at the 39th hour (maximal value), whereas it increased only 25% in the treated buds. Following treatment with cycloheximide, the entry into the S phase was postponed and of low amplitude. However, the recycling nuclei were able to divide. An increase in the mean nuclear and cytoplasmic protein content was a prerequisite if the entry into the S phase of G0–1, nuclei was not to be postponed.

scholarly journals Image-Based Detection of Patient-Specific Drug-Induced Cell-Cycle Effects in Glioblastoma

2018 ◽  
Vol 23 (10) ◽  
pp. 1030-1039
Author(s):  
Damian J. Matuszewski ◽  
Carolina Wählby ◽  
Cecilia Krona ◽  
Sven Nelander ◽  
Ida-Maria Sintorn
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Cell Cycle Phase ◽  
Patient Specific ◽  
Cycle Phase ◽  
Glioblastoma Cells ◽  
Cycle Arrest

Image-based analysis is an increasingly important tool to characterize the effect of drugs in large-scale chemical screens. Herein, we present image and data analysis methods to investigate population cell-cycle dynamics in patient-derived brain tumor cells. Images of glioblastoma cells grown in multiwell plates were used to extract per-cell descriptors, including nuclear DNA content. We reduced the DNA content data from per-cell descriptors to per-well frequency distributions, which were used to identify compounds affecting cell-cycle phase distribution. We analyzed cells from 15 patient cases representing multiple subtypes of glioblastoma and searched for clusters of cell-cycle phase distributions characterizing similarities in response to 249 compounds at 11 doses. We show that this approach applied in a blind analysis with unlabeled substances identified drugs that are commonly used for treating solid tumors as well as other compounds that are well known for inducing cell-cycle arrest. Redistribution of nuclear DNA content signals is thus a robust metric of cell-cycle arrest in patient-derived glioblastoma cells.

scholarly journals Relation between nuclear DNA content and rate of cell growth during interphase in four species of Angiospermae

2015 ◽  
Vol 47 (3) ◽  
pp. 297-305 ◽  
Author(s):  
K. Marciniak ◽  
M. Olszewska ◽  
R. J. Osiecka ◽  
J. Białas
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Helianthus Annuus ◽  
Vicia Faba ◽  
Dna Content ◽  
Cucurbita Pepo ◽  
Nuclear Dna ◽  
Nuclear Dna Content

Among four species of <i>Angiospermae</i> with known nuclear DNA content (<i>Cucurbita pepo</i> - 2.6 pg, <i>Helianthus annuus</i> - 12.0 pg, <i>Vicia faba</i> — 38.0 pg, and <i>Tulipa kaufmanniana</i> - 93.7 pg) the cell growth in the intermitotic period of the cell cycle has been observed to be the fastest in <i>Vicia faba</i>, slower in <i>Helianthus annuus</i> and the slowest in <i>Cucurbita pepo</i> and <i>Tulipa kaufmanniana</i>.

Developmental variability within and between mouse expanding blastocysts and their ICMs

Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 311-336
Author(s):  
Julia C. Chisholm ◽  
Martin H. Johnson ◽  
Paul D. Warren ◽  
Tom P. Fleming ◽  
Susan J. Pickering
Keyword(s):  
Cell Cycle ◽  
Cell Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Cell Number ◽  
Developmental Potential ◽  
Present Evidence ◽  
Cell Cycling

We have attempted to reduce the developmental heterogeneity amongst populations of mouse blastocysts by synchronizing embryos to the first visible signs of blastocoel formation. Using embryos timed in this way, we have examined the extent of variation of inside and outside cell number and of inside cell size, nuclear DNA content and developmental potential, between and within embryos of a similar age postcavitation. The overall impression gained is one of wide heterogeneity in inside:outside cell number ratios and in cell cycling and its relation to cavitation among embryos of similar age postcavitation. However, the simplest explanation of our results suggests that cavitation generally begins at a time when most outside cells are in their sixth developmental cell cycle and that outside cells, as a population, are a little ahead of inside cells in their cell cycling. Additionally we present evidence that, within at least some individual inner cell masses (ICM), there is intraembryo variation in the time at which inside cell developmental potential becomes restricted.

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