Determination of S-period and cell cycle time of 19S hemolysin producing spleen cells of mice cultured in vitro

1972 ◽  
Vol 125 (3) ◽  
pp. 332-338
Author(s):  
W. Lang
Keyword(s):  
Cell Cycle ◽  
Cycle Time ◽  
Spleen Cells ◽  
Cell Cycle Time ◽  
S Period

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.

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 Differences in cell cycle characteristics among patients with acute nonlymphocytic leukemia

Blood ◽  
1987 ◽  
Vol 69 (6) ◽  
pp. 1647-1653 ◽  
Author(s):  
A Raza ◽  
Y Maheshwari ◽  
HD Preisler
Keyword(s):  
Cell Cycle ◽  
Tritiated Thymidine ◽  
S Phase ◽  
Total Cell ◽  
Acute Nonlymphocytic Leukemia ◽  
Cell Cycle Time ◽  
Myeloid Leukemias ◽  
History Of

The proliferative characteristics of myeloid leukemias were defined in vivo after intravenous infusions of bromodeoxyuridine (BrdU) in 40 patients. The percentage of S-phase cells obtained from the biopsies (mean, 20%) were significantly higher (P = .00003) than those determined from the bone marrow (BM) aspirates (mean, 9%). The post- BrdU infusion BM aspirates from 40 patients were incubated with tritiated thymidine in vitro. These double-labeled slides were utilized to determine the duration of S-phase (Ts) in myeloblasts and their total cell cycle time (Tc). The Ts varied from four to 49 hours (mean, 19 hours; median, 17 hours). Similarly, there were wide variations in Tc of individual patients ranging from 16 to 292 hours (mean, 93 hours; median, 76 hours). There was no relationship between Tc and the percentage of S-phase cells, but there was a good correlation between Tc and Ts (r = .8). Patients with relapsed acute nonlymphocytic leukemia (ANLL) appeared to have a longer Ts and Tc than those studied at initial diagnosis. A subgroup of patients at either extreme of Tc were identified who demonstrated clinically documented resistance in response to multiple courses of chemotherapy. We conclude that Ts and Tc provide additional biologic information that may be valuable in understanding the variations observed in the natural history of ANLL.

The Cell Cycle Time In Intestinal Crypts By Simulation of Flm Experiments

1988 ◽  
Vol 21 (6) ◽  
pp. 429-436 ◽  
Author(s):  
H. P. Meinzer ◽  
W. Chen ◽  
B. Sandblad ◽  
N. Wright
Keyword(s):  
Cell Cycle ◽  
Cycle Time ◽  
Cell Cycle Time
Sign in / Sign up

Export Citation Format

Share Document