scholarly journals The Rejoining Time of Chromatid Breaks Induced by Gamma Radiation in Vicia faba Root Tips at 3 °C

1960 ◽  
Vol 7 (1) ◽  
pp. 79-85 ◽  
Author(s):  
J. R. K. Savage ◽  
G. J. Neary ◽  
H. J. Evans
Keyword(s):  
Root Growth ◽  
Vicia Faba ◽  
Low Dose ◽  
Root Meristem ◽  
Root Tips ◽  
Dose Rates ◽  
Low Dose Rate ◽  
Chromatid Aberration ◽  
Γ Rays ◽  
Chromatid Aberrations

The observation was made previously that the reduction in radiosensitivity in Vicia faba (as measured by postirradiation root growth) by prolonging the exposure time from about 10 minutes to 24 hours is much less marked at 3°C. than at 19°C. If chromosome damage is mainly responsible for the reduced root growth, this observation might be explained by a smaller drop in the "two-hit" aberration component, resulting from an increased time for which breaks are available for rejoining at 3°C. This hypothesis was tested by comparing chromatid aberration frequencies in root meristem cells produced by 105 rads of 60Co γ rays, given at dose rates of 19.4 and 0.073 rads per minute. Beans were maintained in aerated water at 2°C. prior to and during irradiation, and at this temperature the rate of development of cells was such that the two different exposure times both occupied a period during which the cell sensitivity was approximately constant. Immediately subsequent to irradiation, the roots were returned to 19°C. and examined cytologically. All chromatid aberrations were less frequent after low dose rate treatment, but only the chromatid interchange reduction was significant. The average time for which breaks are available for reunion, calculated from Lea's G function, was found to be 12 hours (95 per cent C.L. 6 to 24 hours).

scholarly journals Microarray Analysis of Differentially Expressed Genes in the Kidneys and Testes of Mice after Long-term Irradiation with Low-dose-rate γ-rays

2009 ◽  
Vol 50 (3) ◽  
pp. 241-252 ◽  
Author(s):  
Keiko TAKI ◽  
Bing WANG ◽  
Tetsuo NAKAJIMA ◽  
Jianyu WU ◽  
Tetsuya ONO ◽  
...  
Keyword(s):  
Dose Rate ◽  
Differentially Expressed Genes ◽  
Microarray Analysis ◽  
Low Dose ◽  
Differentially Expressed ◽  
Low Dose Rate ◽  
Γ Rays

Adaptive Responses to Low-Dose/Low-Dose-Rate γ Rays in Normal Human Fibroblasts: The Role of Growth Architecture and Oxidative Metabolism

2006 ◽  
Vol 166 (6) ◽  
pp. 849-857 ◽  
Author(s):  
Sonia M. de Toledo ◽  
Nesrin Asaad ◽  
Perumal Venkatachalam ◽  
Ling Li ◽  
Roger W. Howell ◽  
...  
Keyword(s):  
Dose Rate ◽  
Oxidative Metabolism ◽  
Low Dose ◽  
Human Fibroblasts ◽  
Adaptive Responses ◽  
Low Dose Rate ◽  
Normal Human ◽  
Γ Rays

Adiposity in Female B6C3F1 Mice Continuously Irradiated with Low-Dose-Rate γ Rays

2010 ◽  
Vol 173 (3) ◽  
pp. 333-341 ◽  
Author(s):  
S. Nakamura ◽  
I. B. Tanaka ◽  
S. Tanaka ◽  
K. Nakaya ◽  
N. Sakata ◽  
...  
Keyword(s):  
Dose Rate ◽  
Low Dose ◽  
Low Dose Rate ◽  
B6c3f1 Mice ◽  
Γ Rays

scholarly journals Radioprotective effects of cimetidine on rats irradiated by long-term, low-dose-rate neutrons and 60Co γ-rays

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Ding-Wen Jiang ◽  
Qing-Rong Wang ◽  
Xian-Rong Shen ◽  
Ying He ◽  
Tian-Tian Qian ◽  
...  
Keyword(s):  
Dose Rate ◽  
Low Dose ◽  
Low Dose Rate ◽  
Γ Rays

Dose-Rate Effectiveness for Unstable-Type Chromosome Aberrations Detected in Mice after Continuous Irradiation with Low-Dose-Rate γ Rays

2009 ◽  
Vol 171 (3) ◽  
pp. 290-301 ◽  
Author(s):  
Kimio Tanaka ◽  
Atsushi Kohda ◽  
Kenichi Satoh ◽  
Takuo Toyokawa ◽  
Kazuaki Ichinohe ◽  
...  
Keyword(s):  
Dose Rate ◽  
Chromosome Aberrations ◽  
Low Dose ◽  
Continuous Irradiation ◽  
Low Dose Rate ◽  
Γ Rays ◽  
Unstable Type ◽  
Type Chromosome

scholarly journals Transcription Factor-recognition Sequences Potentially Involved in Modulation of Gene Expression after Exposure to Low-dose-rate γ-rays in the Mouse Liver

2011 ◽  
Vol 52 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Guillaume VARES ◽  
Yoshihiko UEHARA ◽  
Tetsuya ONO ◽  
Tetsuo NAKAJIMA ◽  
Bing WANG ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Dose Rate ◽  
Mouse Liver ◽  
Low Dose ◽  
Low Dose Rate ◽  
Γ Rays ◽  
Modulation Of Gene Expression

scholarly journals The microtubule-associated protein CLASP is translationally-regulated in light-dependent root apical meristem growth

2020 ◽  
Author(s):  
Laryssa Halat ◽  
Katherine Gyte ◽  
Geoffrey Wasteneys
Keyword(s):  
Root Growth ◽  
Apical Meristem ◽  
Root Meristem ◽  
Growth Promotion ◽  
Root Apical Meristem ◽  
Root Tips ◽  
Protein Levels ◽  
Hormone Transport ◽  
Dividing Cells ◽  
Root Growth Promotion

ABSTRACTThe ability for plant growth to be optimized, either in the light or dark, depends on the intricate balance between cell division and differentiation in specialized regions called meristems. When Arabidopsis thaliana seedlings are grown in the dark, hypocotyl elongation is promoted, whereas root growth is greatly reduced as a result of changes in hormone transport and a reduction in meristematic cell proliferation. Previous work showed that the microtubule-associated protein CLASP sustains root apical meristem (RAM) size by influencing microtubule (MT) organization and by modulating the brassinosteroid (BR) signalling pathway. Here, we investigated whether CLASP is involved in light-dependent root growth promotion, since dark-grown seedlings have reduced RAM activity that is observed in the clasp-1 null mutant. We showed that CLASP protein levels were greatly reduced in the root tips of dark-grown seedlings, which could be reversed by exposing plants to light. We confirmed that removing seedlings from the light led to a discernible shift in MT organization from bundled arrays, which are prominent in dividing cells, to transverse orientations typically observed in cells that have exited the meristem. BR receptors and auxin transporters, both of which are sustained by CLASP, were largely degraded in the dark. Interestingly, we found that despite the lack of protein, CLASP transcript levels were higher in dark-grown root tips. Together, these findings uncover a mechanism that sustains meristem homeostasis through CLASP, and advances our understanding of how roots modulate their growth according to the amount of light and nutrients perceived by the plant.One Sentence SummaryThe microtubule-associated protein CLASP is regulated at the translational level when root meristem growth is inhibited in dark-grown plants.

scholarly journals Continuous Low-Dose-Rate Irradiation Promotes Growth of Silkworms

Dose-Response ◽  
2017 ◽  
Vol 15 (4) ◽  
pp. 155932581773525 ◽  
Author(s):  
Yuta Shibamoto ◽  
Yoshiaki Kamei ◽  
Koichi Kamei ◽  
Takahiro Tsuchiya ◽  
Natsuto Aoyama
Keyword(s):  
Body Weight ◽  
Standard Deviation ◽  
Dose Rate ◽  
Low Dose ◽  
Low Dose Radiation ◽  
Silk Industry ◽  
Low Dose Rate ◽  
Geiger Muller Counter ◽  
Γ Rays ◽  
Dose Radiation

To investigate the influence of low-dose-rate irradiation on the growth of silkworms, Bombyx mori, eggs of silkworms were randomly divided into 2 groups and were grown on either low-dose-radiation-emitting sheets or control sheets. On the radiation-emitting sheets, the dose rate was measured as 66.0 (4.3) μSv/h (mean [standard deviation]) by a Geiger-Müller counter for α, β, and γ rays and 3.8 (0.3) μSv/h by a survey meter for γ rays. The silkworms became larger when bred on the radiation-emitting sheets, and their body weight was about 25% to 37% heavier on day 42 to 49 after starting the experiment. Continuous low-dose-rate irradiation promoted the growth of silkworms. It should be further investigated whether this phenomenon could be utilized by the silk industry.

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