scholarly journals Lymphocyte proliferation kinetics in malnourished children measured by differential chromatid staining

1982 ◽  
Vol 47 (3) ◽  
pp. 445-450 ◽  
Author(s):  
P. Balakrishna Murthy ◽  
M. Abdul Rahiman ◽  
P. G. Tulpule
Keyword(s):  
Cell Cycle ◽  
Lymphocyte Proliferation ◽  
Cycle Duration ◽  
In Vitro Proliferation ◽  
Culture Time ◽  
Malnourished Children ◽  
Cell Cycle Duration ◽  
Lymphocyte Activity ◽  
Proliferation Of Lymphocytes

1. Utilizing the bromodeoxyuridine differential-chromatid labelling technique the in vitro proliferation of lymphocytes from children with kwashiorkor was followed in phytohaemagglutinin-stimulated cultures and compared with controls.2. Analyses of first, second and third or subsequent division cells as a function of culture time between 40 and 96 h showed that cell-cycle duration was prolonged in kwashiorkor cultures. The extent of this increase was approximately 4.5 h for the first-division cells and 1.5 h for third-division cells.3. The peak for second-division cells was depressed in kwashiorkor cultures.4. A decreased number of third or subsequent-division cells was observed in kwashiorkor cultures at all time points studied.5. These findings suggest that the loss in lymphocyte activity to PHA in malnourished children in general could be due to an increase in cell-cycle duration of responding lymphocytes.

Kinetics of in vitro ageing of mouse embryo fibroblasts

1984 ◽  
Vol 65 (1) ◽  
pp. 163-175
Author(s):  
C. Karatza ◽  
W.D. Stein ◽  
S. Shall
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Mouse Embryo ◽  
Growth Pattern ◽  
Cell Strain ◽  
Growth Fraction ◽  
Cycle Duration ◽  
Cell Cycle Duration ◽  
Kinetics Of

The kinetics of ageing of normal mouse embryo fibroblast cells in culture have been determined. The growth pattern during every passage was established. It was observed that the growth pattern was not exponential, but that the growth rate declined progressively both within and with every passage. We also estimated the cell cycle parameters using the Fraction of Labelled Mitoses method at every passage. We found that the cell cycle duration was constant throughout the lifespan of this cell strain; the median value of the cell cycle duration was found to be 15.5 +/− 0.5 h (S.D., n = 8). From these two sets of observations we infer that the fraction of dividing cells declines smoothly from the beginning of the culture. Our data exclude quite positively any description of ageing of the fibroblast population in terms of a catastrophe or any abrupt change in the population. Our data are also inconsistent with a linear decline in growth fraction. On the contrary, we observed that there was a gradual and smooth decline in the growth rate of the strain, due to a smoothly declining growth fraction. This smooth change in the growth behaviour of this cell strain is accurately described by the mortalization theory of Shall & Stein in which the single parameter gamma (gamma), describes the change in reproductive potential over the entire lifespan. The parameter gamma describes the rate at which the doubling time of the culture increases. It is the number of generations at which half of the newborn cells are themselves reproductively sterile. Our present data provided an estimate of gamma for this cell strain, which was consistent during the entire lifespan of the strain; the best estimate of gamma for this cell strain was 20.3 +/− 0.6 generations (S.D., n = 19).

158 RELATIONSHIP BETWEEN FOURTH CELL CYCLE DURATION AND POST-TRANSFER VIABILITY IN IN VITRO-FERTILIZED BOVINE EMBRYOS

2012 ◽  
Vol 24 (1) ◽  
pp. 191
Author(s):  
S. Sugimura ◽  
Y. Hashiyada ◽  
Y. Aikawa ◽  
M. Ohtake ◽  
H. Matsuda ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Embryo Transfer ◽  
T Test ◽  
Cycle Duration ◽  
Bovine Embryos ◽  
Cell Cycles ◽  
Cell Cycle Duration ◽  
Student’S T ◽  
Student’S T Test

In cattle, the prediction of embryonic viability after embryo transfer is an important research target. A previous study has indicated that the duration of the fourth cell cycle at the time of maternal-zygotic transition, which is involved in in vitro embryonic development, may be an indicator of blastocyst formation; this study showed that embryos with a short fourth cell cycle have a better potential of developing into blastocysts than those with a long fourth cell cycle (Lequarre et al. 2003 Biol. Reprod. 69, 1707–1713). However, the relationship between the fourth cell cycle duration and post-transfer viability of embryos is unclear. The aim of the present study was to examine the effect of the fourth cell cycle duration on embryo development after embryo transfer. Twenty-five IVF bovine embryos were cultured in well-of-the-well culture dishes contained 125 μ of CR1aa supplemented with 5% calf serum at 38.5°C in 5% O2 and 5% CO2 for 168 h after insemination. In vitro development of the embryos was monitored using time-lapse cinematography (Sugimura et al. 2010 Biol. Reprod. 83, 970–978). We found that 61% of the blastocysts had a long fourth cell cycle (41.5 ± 5.9 h), which is commonly referred to as the lag phase, whereas the remaining embryos had a short fourth cell cycle (7.4 ± 4.5 h). All the embryos with a short fourth cell cycle exhibited a lag phase in the next cell cycle (32.9 ± 6.6 h). Moreover, embryos with a short fourth cell cycle were found to have a higher blastocyst rate (75.8%) than those with a long fourth cell cycle (48.1%; Student's t-test, P < 0.01). However, embryonic cell number, apoptosis incidence, chromosomal abnormality and O2 consumption were found to be identical between the 2 groups (Student's t-test, P > 0.05). Real-time reverse-transcription PCR results of the individual blastocysts showed that the relative expression of 5 genes related to pregnancy reorganization, placentation and fetal growth—namely, CDX2, IFN-τ, PLAC8, AKR1B1 and IGF2R—did not differ between the 2 groups (Student's t-test, P > 0.05). Furthermore, blastocysts derived from embryos with long (n = 30) and short (n = 19) fourth cell cycles were transferred into 49 recipient cows; we did not observe any difference between the long and short fourth cell cycles on the rates of pregnancy (long vs short fourth cell cycle, 30.0 vs 52.6%) and delivery (long vs short fourth cell cycle, 30.0 vs 47.4%; Yates' corrected chi-square test, P > 0.10). These results show that blastocysts derived from embryos with either long or short fourth cell cycles have identical developmental competence after embryo transfer. Therefore, the fourth cell cycle duration during maternal-zygotic transition appears to be unavailable as the indicator of post-transfer viability of IVF bovine embryos. This work was supported by the Research and Developmental Program for New Bio-Industry Initiatives.

Genome in toto

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 361-362 ◽  
Author(s):  
Alexander E Vinogradov
Keyword(s):  
Cell Cycle ◽  
Genome Evolution ◽  
Genome Size ◽  
Cycle Duration ◽  
Noncoding Dna ◽  
Cell Cycle Duration ◽  
The Relationship

At a certain temperature, which is a compromise for temperatures at which the species are adapted, the relationship between genome size and cell cycle duration during synchronous cleavage divisions can be very strong (r = 1.00, P < 0.01) in four closely related frogs, suggesting a functional dependence.Key words: genome size, genome evolution, genome cytoecology, noncoding DNA, cell cycle duration.

Stimulation of activated rat T cells in vitro by Listeria monocytogenes antigens

1980 ◽  
Vol 29 (3) ◽  
pp. 1102-1110
Author(s):  
M C Woan ◽  
U K Forsum ◽  
D D McGregor
Keyword(s):  
T Cells ◽  
Listeria Monocytogenes ◽  
Soluble Extract ◽  
In Vitro Proliferation ◽  
Surface Immunoglobulin ◽  
Peripheral T Cells ◽  
Proliferation Of Lymphocytes ◽  
Antigen Presenting ◽  
Stimulation Of

A soluble extract of Listeria monocytogenes bound firmly and in similar amounts to a variety of rat cells. Cells that bound this material differed in their capacity to stimulate the in vitro proliferation of lymphocytes obtained from the thoracic duct of Listeria-immune donors. The capacity of cells to serve as antigen-presenting cells in this system coincided or closely overlapped the expression on these cells of an Ia antigen-like structure. Three lines of evidence indicate that T cells respond to L. monocytogenes antigen: the responder cells are members of a nylon-wool nonadherent population that lacks readily detectable surface immunoglobulin; they express determinants recognized by the W3/25 monoclonal antibody (a surface marker of rat peripheral T cells); and they are stimulated optimally by L. monocytogenes antigen when the latter is displayed on cells that share a haplotype with the responder lymphocytes.

scholarly journals Lateral Root Priming Synergystically Arises from Root Growth and Auxin Transport Dynamics

2018 ◽  
Author(s):  
Thea van den Berg ◽  
Kirsten H. ten Tusscher
Keyword(s):  
Cell Cycle ◽  
Root Growth ◽  
Lateral Root ◽  
Root Formation ◽  
Growth Dynamics ◽  
Root Tip ◽  
Cycle Duration ◽  
Elongation Zone ◽  
Lateral Root Formation ◽  
Cell Cycle Duration

AbstractThe root system is a major determinant of plant fitness. Its capacity to supply the plant with sufficient water and nutrients strongly depends on root system architecture, which arises from the repeated branching off of lateral roots. A critical first step in lateral root formation is priming, which prepatterns sites competent of forming a lateral root. Priming is characterized by temporal oscillations in auxin, auxin signalling and gene expression in the root meristem, which through growth become transformed into a spatially repetitive pattern of competent sites. Previous studies have demonstrated the importance of auxin synthesis, transport and perception for the amplitude of these oscillations and their chances of producing an actual competent site. Additionally, repeated lateral root cap apoptosis was demonstrated to be strongly correlated with repetitive lateral root priming. Intriguingly, no single mutation has been identified that fully abolishes lateral root formation, and thusfar the mechanism underlying oscillations has remained unknown. In this study, we investigated the impact of auxin reflux loop properties combined with root growth dynamics on priming, using a computational approach. To this end we developed a novel multi-scale root model incorporating a realistic root tip architecture and reflux loop properties as well as root growth dynamics. Excitingly, in this model, repetitive auxin elevations automatically emerge. First, we show that root tip architecture and reflux loop properties result in an auxin loading zone at the start of the elongation zone, with preferential auxin loading in narrow vasculature cells. Second, we demonstrate how meristematic root growth dynamics causes regular alternations in the sizes of cells arriving at the elongation zone, which subsequently become amplified during cell expansion. These cell size differences translate into differences in cellular auxin loading potential. Combined, these properties result in temporal and spatial fluctuations in auxin levels in vasculature and pericycle cells. Our model predicts that temporal priming frequency predominantly depends on cell cycle duration, while cell cycle duration together with meristem size control lateral root spacing.

scholarly journals Effects of cell cycle variability on lineage and population measurements of mRNA abundance

2020 ◽  
Author(s):  
Ruben Perez-Carrasco ◽  
Casper Beentjes ◽  
Ramon Grima
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Negative Binomial ◽  
Eukaryotic Cell ◽  
Cycle Duration ◽  
Cell Cycle Duration ◽  
Monotonically Decreasing Function ◽  
Binomial Mixture ◽  
A Cell ◽  
The Mean

AbstractMany models of gene expression do not explicitly incorporate a cell cycle description. Here we derive a theory describing how mRNA fluctuations for constitutive and bursty gene expression are influenced by stochasticity in the duration of the cell cycle and the timing of DNA replication. Analytical expressions for the moments show that omitting cell cycle duration introduces an error in the predicted mean number of mRNAs that is a monotonically decreasing function of η, which is proportional to the ratio of the mean cell cycle duration and the mRNA lifetime. By contrast, the error in the variance of the mRNA distribution is highest for intermediate values of η consistent with genome-wide measurements in many organisms. Using eukaryotic cell data, we estimate the errors in the mean and variance to be at most 3% and 25%, respectively. Furthermore, we derive an accurate negative binomial mixture approximation to the mRNA distribution. This indicates that stochasticity in the cell cycle can introduce fluctuations in mRNA numbers that are similar to the effect of bursty transcription. Finally, we show that for real experimental data, disregarding cell cycle stochasticity can introduce errors in the inference of transcription rates larger than 10%.

Sign in / Sign up

Export Citation Format

Share Document