scholarly journals 5-AMINOURACIL TREATMENT

1971 ◽  
Vol 48 (2) ◽  
pp. 248-252 ◽  
Author(s):  
S. H. Socher ◽  
D. Davidson
Keyword(s):  
Mitotic Index ◽  
Vicia Faba ◽  
Cell Population ◽  
Lateral Roots ◽  
Proliferating Cells ◽  
Dividing Cells ◽  
Proliferating Cell ◽  
Two Populations

Treatment of Vicia faba lateral roots with a range of concentrations of 5-aminouracil (5-AU) indicate that cells are stopped at a particular point in interphase. The timing of the fall in mitotic index suggests that cells are held at the S - G2 transition. When cells are held at this point, treatments with 5-AU can be used to estimate the duration of G2 + mitosis/2 of proliferating cells. Treatment with 5-AU can also be used to demonstrate the presence of subpopulations of dividing cells that differ in their G2 duration. Using this method, 5-AU-induced inhibition, we have confirmed that in V. faba lateral roots there are two populations of dividing cells: (a) a fast-dividing population, which makes up ∼85% of the proliferating cell population and has a G2 + mitosis/2 duration of 3.3 hr, and (b) a slow-dividing population, which makes up ∼15% of dividing cells and has a G2 duration in excess of 12 hr. These estimates are similar to those obtained from percentage labeled mitosis (PLM) curves after incorporation of thymidine-3H.

scholarly journals EVIDENCE FROM THYMIDINE-3H-LABELED MERISTEMS OF VICIA FABA OF TWO CELL POPULATIONS

1968 ◽  
Vol 39 (2) ◽  
pp. 332-338 ◽  
Author(s):  
P. L. Webster ◽  
D. Davidson
Keyword(s):  
Vicia Faba ◽  
Cycle Time ◽  
Spatial Organization ◽  
Tritiated Thymidine ◽  
Lateral Roots ◽  
Relative Size ◽  
Cycle Duration ◽  
Pulse Label ◽  
Two Populations ◽  
Peak Value

Treatments with tritiated thymidine (TdR-3H) have revealed the existence of two populations of mitotically active cells in meristems of lateral roots of Vicia faba. A rapidly dividing population, with a cycle time of 14 hr, constitutes about half the cells in the meristem. A second population of cells, with a cycle time in excess of 30 hr, is also present. Estimates of the relative size of this slowly dividing population are more difficult to make, but we calculate that this population includes 27–43% of meristem cells. The remaining fraction of the meristem is made up of cells that divide rarely or not at all. Since, at all times, both populations contribute to the mitotic index, the curve of the percentage of labeled mitoses that can be determined after a pulse label with TdR-3H differs from the curve expected of an ideal population in an important way: the peak value of the curve of the percentage of labeled mitoses is always less than 100%, usually between 75 and 80%. This heterogeneity within a meristem must be borne in mind in terms of the response of meristems to disruptive treatments, the mechanisms controlling mitotic cycle duration, and the spatial organization of a heterogeneous population in an organ that shows polarized growth.

Haemopoiesis in Lepidoptera. III. A note on the multiplication of spherule cells and granular haemocytes

1983 ◽  
Vol 61 (1) ◽  
pp. 275-277 ◽  
Author(s):  
J. W. Arnold ◽  
C. F. Hinks
Keyword(s):  
Mitotic Index ◽  
Alcian Blue ◽  
Maximum Production ◽  
Spherule Cell ◽  
Dividing Cells ◽  
Lepidoptera Noctuidae ◽  
Potential Maximum ◽  
Hematoxylin Eosin ◽  
Cell Mitosis

Blood films from early sixth instar larvae of Euxoa declarata (Lepidoptera: Noctuidae) stained in hematoxylin – eosin – alcian blue showed unequivocal examples of mitosis in spherule cells. The improved visibility of mitosis and the estimation of the mitotic index from counts of dividing cells per 1000 cells of each type indicated a far greater potential maximum production of spherule cells and granular haemocytes by mitosis than reported previously. Certain other methods of staining showed similar clear examples of spherule cell mitosis.

scholarly journals Cell proliferation controls body size growth, tentacle morphogenesis, and regeneration in hydrozoan jellyfish Cladonema pacificum

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7579 ◽  
Author(s):  
Sosuke Fujita ◽  
Erina Kuranaga ◽  
Yu-ichiro Nakajima
Keyword(s):  
Cell Proliferation ◽  
Body Size ◽  
Environmental Changes ◽  
Size Control ◽  
Cellular Mechanisms ◽  
Proliferating Cells ◽  
Size Growth ◽  
Local Cell ◽  
Proliferating Cell

Jellyfish have existed on the earth for around 600 million years and have evolved in response to environmental changes. Hydrozoan jellyfish, members of phylum Cnidaria, exist in multiple life stages, including planula larvae, vegetatively-propagating polyps, and sexually-reproducing medusae. Although free-swimming medusae display complex morphology and exhibit increase in body size and regenerative ability, their underlying cellular mechanisms are poorly understood. Here, we investigate the roles of cell proliferation in body-size growth, appendage morphogenesis, and regeneration using Cladonema pacificum as a hydrozoan jellyfish model. By examining the distribution of S phase cells and mitotic cells, we revealed spatially distinct proliferating cell populations in medusae, uniform cell proliferation in the umbrella, and clustered cell proliferation in tentacles. Blocking cell proliferation by hydroxyurea caused inhibition of body size growth and defects in tentacle branching, nematocyte differentiation, and regeneration. Local cell proliferation in tentacle bulbs is observed in medusae of two other hydrozoan species, Cytaeis uchidae and Rathkea octopunctata, indicating that it may be a conserved feature among hydrozoan jellyfish. Altogether, our results suggest that hydrozoan medusae possess actively proliferating cells and provide experimental evidence regarding the role of cell proliferation in body-size control, tentacle morphogenesis, and regeneration.

scholarly journals Interacting populations affecting proliferation of leukemic cells in culture

Blood ◽  
1975 ◽  
Vol 45 (4) ◽  
pp. 485-493
Author(s):  
MT Aye ◽  
JE Till ◽  
EA McCulloch
Keyword(s):  
Blood Cells ◽  
Cell Separation ◽  
Culture Method ◽  
Leukemic Cells ◽  
Velocity Sedimentation ◽  
Proliferating Cells ◽  
Cells In Culture ◽  
Interacting Populations ◽  
Cytogenetic Studies ◽  
Two Populations

Peripheral blood cells from three patients with acute leukemic have been studied using a suspension culture method previously described.1 Cytogenetic studies in two of the patients permitted the identification of the proliferating cells in the cultures as being derived from a leukemic population. Cell separation studies using velocity sedimentation supported the concept that growth of the leukemic cells in culture is dependent on an interaction between two populations of leukemic cells.

Anaplasia and Heterogeneity of Gfap Expression in Gliomas

1986 ◽  
Vol 72 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Davide Schiffer ◽  
Maria Teresa Giordana ◽  
Isabella Germano ◽  
Alessandro Mauro
Keyword(s):  
Glial Fibrillary Acidic Protein ◽  
Tumor Cells ◽  
Cell Population ◽  
Malignant Gliomas ◽  
Reactive Astrocytes ◽  
Mutation Rates ◽  
Protein Distribution ◽  
Gfap Expression ◽  
Proliferating Cell ◽  
Negative Population

GFAP (glial fibrillary acidic protein) distribution was investigated in selected areas of glioblastomas and astrocytomas. The proliferating cell population of glioblastomas was GFAP negative and contained many mitoses which were also negative. The old, deeply located areas were composed of cells with visible cytoplasm, intensely GFAP-positive; mitoses in these areas were both GFAP-positive and negative. GFAP-positive reactive astrocytes, once trapped in the tumor, were no longer distinguishable from positive tumor cells. They sometimes contained mitoses. In astrocytoma, anaplasia was due to the development of a GFAP-negative population with negative mitoses. The problem of dedifferentiation and differentiation of malignant gliomas in discussed taking into account the possiblity that malignancy may be due to increasing mutation rates of tumors. The problem of redifferentiation of already dedifferentiated cells is also discussed.

Sign in / Sign up

Export Citation Format

Share Document