DETERMINATION OF CELL CYCLE IN PLANTS USING BrdU-FPG

1980 ◽  
Vol 22 (2) ◽  
pp. 305-308 ◽  
Author(s):  
Kirby J. Evans ◽  
W. Gary Filion
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Cycle Time ◽  
Differential Staining ◽  
Root Tip ◽  
Cell Cycle Time ◽  
Sister Chromatids ◽  
Vicia Faba L ◽  
Established Cell

The BrdU-FPG method for differential staining of sister chromatids was employed to estimate the cell cycle time in two plants species. The protocol is based upon the ability to differentiate cytologically between chromosomes which have completed two or three DNA synthesis phases. Vicia faba L. which has a well established cell cycle time was used to verify the technique. Utilizing this method the cell cycle time of Zebrina pendula Schnizl. root tip meristem cells was determined to be 17.0 hours.

CHANGES IN CELL PROLIFERATION RATE IN MOUSE UTERINE EPITHELIUM DURING CONTINUOUS OESTROGEN TREATMENT

1974 ◽  
Vol 61 (1) ◽  
pp. 117-121 ◽  
Author(s):  
AUDREY E. LEE ◽  
L. A. ROGERS ◽  
GAIL TRINDER
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Synthesis ◽  
Mitotic Index ◽  
Cycle Time ◽  
Luminal Epithelium ◽  
Cell Cycle Time ◽  
Oestrogen Treatment ◽  
Probability Of Transition ◽  
The Mean

SUMMARY Fraction of labelled mitoses (FLM) curves were constructed for mouse uterine luminal epithelium during oestradiol treatment; on day 2 when mitosis was high, and on days 4 and 9 when mitosis was low. No difference was found between the duration of DNA synthesis on these 3 days. The distance between the first and second peaks, usually taken as an estimate of the mean cell cycle time, did not change significantly between days 2 and 4, although the labelling index fell from 38 to 8%. The second peaks of the FLM curves became progressively lower on the three days examined, which was consistent with the interpretation that there was a reduction in the probability of transition of cells from G1 (the post-mitotic period) into the replicative phase of the cell cycle, resulting in the observed fall in mitotic index.

scholarly journals An autoradiographic study of cellular proliferaton, DNA synthesis and cell cycle variability in the rat liver caused by phenobarbital-induced oxidative stress: The protective role of melatonin

2007 ◽  
Vol 12 (3) ◽  
Author(s):  
Gamal El-Sokkary
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Lipid Peroxidation ◽  
Dna Synthesis ◽  
Rat Liver ◽  
Cycle Time ◽  
Proliferative Activity ◽  
Labelling Index ◽  
Male Rats ◽  
Cell Cycle Time

AbstractThe protective effect of melatonin against phenobarbital-induced oxidative stress in the rat liver was measured based on lipid peroxidation levels (malondialedyde and 4-hydroxyalkenals). Cellular proliferation, DNA synthesis and cell cycle duration were quantitated by the incorporation of 3H-thymidine, detected by autoradiography, into newly synthesized DNA. Two experiments were carried out in this study, each on four equal-sized groups of male rats (control, melatonin [10 mg/kg], phenobabital [20 mg/kg] and phenobarbital plus melatonin). Experiment I was designed to study the proliferative activity and rate of DNA synthesis, and measure the levels of lipid peroxidation, while experiment II was for cell cycle time determination. Relative to the controls, the phenobarbital-treated rats showed a significant increase (P < 0.01) in the lipid peroxidation levels (30.7%), labelling index (69.4%) and rate of DNA synthesis (37.8%), and a decrease in the cell cycle time. Administering melatonin to the phenobarbital-treated rats significantly reduced (P < 0.01) the lipid peroxidation levels (23.5%), labelling index (38.2%) and rate of DNA synthesis (29.0%), and increased the cell cycle time. These results seem to indicate that the stimulatory effect of phenobarbital on the oxidized lipids, proliferative activity, kinetics of DNA synthesis and cell cycle time alteration in the liver may be one of the mechanisms by which the non-genotoxic mitogen induces its carcinogenic action. Furthermore, melatonin displayed powerful protection against the toxic effect of phenobarbital.

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.

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