scholarly journals The effects of pulse cycloheximide treatments on the light-induced recovery of mitotic divisions in antheridial filaments of Chara vulgaris

2014 ◽  
Vol 68 (1) ◽  
pp. 9-14
Author(s):  
Maria Kwiatkowska ◽  
Sławomir Malinowski ◽  
Janusz Maszewski
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Mitotic Activity ◽  
Total Darkness ◽  
Chara Vulgaris ◽  
Cell Divisions ◽  
Cycle Arrest ◽  
Starting Point ◽  
G2 Phase ◽  
Preliminary Study

Within the proliferative period of spermatogenesis in <em>Chara vulgaris</em>, the progression throughout successive cell divisions in antheridial filaments is greatly influenced by changes in photoperiodic conditions. The extended (4-day) period of total darkness brings about cell cycle arrest in the early G2 phase. The recovery of mitosis requires about 20 hours of exposition to light. In the present study, a series of 8 pulse incubations of plants in cycloheximide (Cx; 2.5 mg/I, 2.5 h each pulse) were performed within the period elapsing till the resumption of mitotic divisions. Depending on the time of treatment, the effects induced by Cx vary considerably. Within the first 10 hs of exposition to light, incubations with Cx result in the delays of mitoses; within the period between the 10th and the 17th h, mitotic divisions become blocked, and, following the 17.5 h of light-induced recovery, no influence of Cx is noticed on mitotic activity, as compared with the untreaed control plants. The obtained results provide a starting point for the characteristic of proteins synthesized during the G2 phase and a preliminary study on those mechanisms, which become engaged in the regulation of the G1-deficient cell cycle evidenced in antheridial filaments of <em>Chara</em>.

scholarly journals Changes in the number and size of nucleoli of Chara vulgaris L. antheridial filament cells during the period preceding light-induced re-initiation of cell divisions following a mitodepressive effect of darkness

2014 ◽  
Vol 68 (4) ◽  
pp. 251-254
Author(s):  
Maria Kwiatkowska ◽  
Ewa Papiernik
Keyword(s):  
Cell Cycle ◽  
Developmental Stage ◽  
Mitotic Activity ◽  
Silver Staining ◽  
Staining Method ◽  
Chara Vulgaris ◽  
Cell Divisions ◽  
A Cell ◽  
Silver Staining Method

The changes in number and size of nucleoli of <em>Chara vulgaris</em> antheridial filament cells were monitored with the use of Howell and Black's silver staining method. After a 3-day mitodepressive treatment with darkness the cells were exposed to light which reactivated mitotic activity after 18-20 hours. Eight-celled antheridial filaments were observed. In the period preceding light-induced re-initiation of mitoses a gradual reconstruction of the number and size of nucleoli characteristic of control, as well as their total area per nucleus appeared. The obtained results indicate that one of the important conditions for a cell to be able to divide is accumulation of nucleolus components characteristic of a given developmental stage and this controls nucleologenesis of the subsequent cell cycle.

scholarly journals Ethanol Extract of Croton Kongensis Promotes Cell Cycle Arrest and Consequently Inhibits Anchorage-Independent Growth of Cervical Cancer Hela Cells

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
Nguyen Thi Bich Loan ◽  
Nguyen Lai Thanh ◽  
Pierre Duez ◽  
Nguyen Dinh Thang
Keyword(s):  
Cell Cycle ◽  
Cervical Cancer ◽  
Cell Cycle Arrest ◽  
Hela Cells ◽  
Ethanol Extract ◽  
Soft Agar ◽  
Anticancer Activities ◽  
Anchorage Independent Growth ◽  
Cycle Arrest ◽  
G2 Phase

Extracts from Croton kongenis present anticancer activities on various cancers. However, there is no research conducted to investigate the effects of Croton kongenis extracts on cervical cancer as well as on zebrafish. In this study, we demonstrated that Croton kongenis ethanol extract expressed high toxicity to cervical cancer Hela cells with an IC50 dose of 20.4 µg/mL and to zebrafish embryos with malformations, lethality and hatching inhibition at 72-hpf at effective dose of 125 µg/mL. Interestingly, treatment with Croton kongenis ethanol extract caused cell-cycle-arrest at the G2 phase. Particularly, percentages of Croton kongenis ethanol extract-treated cells in G1, S, G2/M were 70%, 6% and 23%, while percentages of control cells in G1, S, G2/M were 65%, 15% and 18%, respectively. Consistent with cell-cycle-arrest, the expressions of CDKN1A, CDNK2A and p53 in Croton kongenis ethanol extract-treated cells were up-regulated 2.0-, 1.65- and 1.8-fold, respectively. Significantly, treatment with Croton kongenis ethanol extract inhibited anchorage-independent growth of Hela cells; the number of colonies formed in soft-agar of Croton kongenis ethanol extract-treated cells was only one-fourth of that of control cells. In conclusion, we suggest that Croton kongenis ethanol extract could be able to use as a traditional medicine for treatment of cervical cancer.

scholarly journals Notch Signaling and Developmental Cell-Cycle Arrest in Drosophila Polar Follicle Cells

2009 ◽  
Vol 20 (24) ◽  
pp. 5064-5073 ◽  
Author(s):  
Li-Fang Shyu ◽  
Jianjun Sun ◽  
Hui-Min Chung ◽  
Yi-Chun Huang ◽  
Wu-Min Deng
Keyword(s):  
Cell Cycle ◽  
Notch Signaling ◽  
Cell Cycle Arrest ◽  
Developmental Regulation ◽  
Cell Types ◽  
Follicle Cells ◽  
Cycle Arrest ◽  
G2 Phase ◽  
G2 Cell Cycle Arrest ◽  
Regulation Of Cell Cycle

Temporal and spatial regulation of cell division is critical for proper development of multicellular organisms. An important aspect of this regulation is cell-cycle arrest, which in many cell types is coupled with differentiated status. Here we report that the polar cells—a group of follicle cells differentiated early during Drosophila oogenesis—are arrested at G2 phase and can serve as a model cell type for investigation of developmental regulation of cell-cycle arrest. On examining the effects of String, a mitosis-promoting phosphatase Cdc25 homolog, and Notch signaling in polar cells, we found that misexpression of String can trigger mitosis in existing polar cells to induce extra polar cells. Normally, differentiation of the polar cells requires Notch signaling. We found that the Notch-induced extra polar cells arise through recruitment of the neighboring cells rather than promotion of proliferation, and they are also arrested at G2 phase. Notch signaling is probably involved in down-regulating String in polar cells, thus inducing the G2 cell-cycle arrest.

Low-Dose Hyper-radiosensitivity: A Consequence of Ineffective Cell Cycle Arrest of Radiation-Damaged G2-Phase Cells

2004 ◽  
Vol 161 (3) ◽  
pp. 247-255 ◽  
Author(s):  
B. Marples ◽  
B. G. Wouters ◽  
S. J. Collis ◽  
A. J. Chalmers ◽  
M. C. Joiner
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Low Dose ◽  
Cycle Arrest ◽  
G2 Phase

scholarly journals The mammalian mismatch repair protein MSH2 is required for correct MRE11 and RAD51 relocalization and for efficient cell cycle arrest induced by ionizing radiation in G2 phase

Oncogene ◽  
2003 ◽  
Vol 22 (14) ◽  
pp. 2110-2120 ◽  
Author(s):  
Annapaola Franchitto ◽  
Pietro Pichierri ◽  
Rita Piergentili ◽  
Marco Crescenzi ◽  
Margherita Bignami ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ionizing Radiation ◽  
Cell Cycle Arrest ◽  
Mismatch Repair ◽  
Cycle Arrest ◽  
Repair Protein ◽  
G2 Phase ◽  
Mismatch Repair Protein

Cell cycle checkpoints and pathogenesis of HIV-1 infection: a brief overview

2015 ◽  
Vol 26 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Kesava Rao V. Kurapati ◽  
Thangavel Samikkannu ◽  
Venkata Subba Rao Atluri ◽  
Madhavan P.N. Nair
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cell Cycle Checkpoints ◽  
Hiv Pathogenesis ◽  
Multiple Events ◽  
Cycle Arrest ◽  
G2 Phase ◽  
Hiv 1

AbstractTo understand HIV pathogenesis or development is no simple undertaking and neither is the cell cycle which is highly complex that requires the coordination of multiple events and machinery. It is interesting that these two processes are interrelated, intersect and interact as HIV-1 infection results in cell cycle arrest at the G2 phase which is accompanied by massive CD4

scholarly journals Knockdown of Regulator of Cullins-1 (ROC1) Expression Induces Bladder Cancer Cell Cycle Arrest at the G2 Phase and Senescence

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e62734 ◽  
Author(s):  
Wei Wang ◽  
Zhihong Liu ◽  
Ping Qu ◽  
Zhengdong Zhou ◽  
Yigang Zeng ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bladder Cancer ◽  
Cell Cycle Arrest ◽  
Cancer Cell ◽  
Bladder Cancer Cell ◽  
Cycle Arrest ◽  
G2 Phase
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