scholarly journals NUCLEAR DIVISION IN TRADESCANTIA VIRGINIANA

1934 ◽  
Vol 9 (4) ◽  
pp. 845-849 ◽  
Author(s):  
Beatrice Lehman ◽  
F. M. Andrews
Keyword(s):  
Nuclear Division ◽  
Tradescantia Virginiana

In Vitro Genotoxicity and Molecular Docking Study of Ellagic Acid

2020 ◽  
Vol 16 (7) ◽  
pp. 1072-1082
Author(s):  
Tuba C. Dördü ◽  
Rüştü Hatipoğlu ◽  
Mehmet Topaktaş ◽  
Erman S. İstifli
Keyword(s):  
Dna Damage ◽  
Molecular Docking ◽  
Comet Assay ◽  
Treatment Period ◽  
Chromosome Aberration ◽  
Human Lymphocyte ◽  
Sister Chromatid ◽  
Ellagic Acid ◽  
Sister Chromatid Exchange ◽  
Nuclear Division

Background: Ellagic Acid (EA) is a polyphenolic compound that is classified in the natural antioxidants group. Polyphenolic compounds that exert antioxidant activity possess particular importance for scientists, food producers and consumers due to their positive effects on human health. However, despite considerable evidence that EA shows antigenotoxic activity by binding to DNA, there is no systematic genotoxicity study of this substance, which can covalently bind to DNA. This study aims to reveal the possible genotoxic activity of EA using widely accepted assays for the assessment of DNA clastogenic activity: sister chromatid exchange, chromosome aberration, micronucleus and comet assays as well as to predict the interactions among EA and DNA through molecular docking. Methods: Different assays were carried out to identify the clastogenic activity of EA on human lymphocyte DNA using Sister Chromatid Exchange (SCE), Chromosome Aberration (CA), Micronucleus (MN) and single-cell gel electrophoresis (SCGE/comet) assays. For this aim, human peripheral blood lymphocytes were treated with EA (60, 80 and 100 μg/ml) for 24 and 48 hrs in the SCE, CA and MN assays and for 1 hr in the comet assay. Furthermore, molecular docking experiments were also performed to calculate the binding energy of EA on human B-DNA structure (B-DNA dodecamer) as well as to predict noncovalent interactions among these macromolecules. Results: At the concentrations and treatment times (24- or 48-hr) tested, EA did not induce either SCE or Chromosome Aberrations (CAs) as compared to the negative and solvent controls. Although EA slightly increased the percentage of Micronucleated Binuclear (%MNBN) cells as well as the percentage of Micronucleus (%MN) in 24 or 48-hr treatment periods at all concentrations, this increase was not statistically significant as compared to both controls. The effect of EA on DNA replication (nuclear division) was determined by the Proliferation Index (PI), the Nuclear Division Index (NDI) and the Mitotic Index (MI). No statistically significant differences were observed in the PI or NDI in 24- or 48-hr treatment periods in human lymphocyte cultures treated with EA at various concentrations. EA generally had no significant effect on the MI, as observed with the PI and NDI. Discussion: Although the concentrations of 60 and 80 μg/mL at a 24-hr treatment period and the concentrations of 60 μg/mL and 100 μg/mL at 48-hr treatment period generally decreased the MI, those decreases were not statistically significant when compared to negative and solvent controls. Moreover, none of the concentrations of EA tested in this study were able to increase DNA damage determined by the tail DNA length, %DNA in tail and tail moment parameters in the comet assay. Although the amount of DNA damage in the comet assay decreased with increasing concentrations of EA, this decrease was not statistically significant as compared to both controls. However, molecular docking experiments interestingly showed that the binding free energy of EA with B-DNA was -7.84 kcal/mol-1, indicating a strong interaction between the two molecules. Conclusion : Although the findings of our study show that EA does not have genotoxic potential in human chromosomes, molecular docking experiments revealed strong hydrogen bonding between EA and B-DNA molecules. Therefore, it has been proposed that the prevailing information suggesting that the molecules that bind to DNA cause genotoxic effects should be reconsidered from a wider perspective.

Antiproliferative and Genotoxic Action of an Underexploited Organoteluran Derivative on Sarcoma 180 Cells

2020 ◽  
Vol 20 ◽  
Author(s):  
Maria L.L. Barreto do Nascimento ◽  
Antonielly Campinho dos Reis ◽  
José V.O. Santos ◽  
Helber A. Negreiros ◽  
Felipe C. Carneiro da Silva ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Nuclear Division ◽  
Micronucleus Test ◽  
Mutagenic Activity ◽  
Chemical Compounds ◽  
Negative Control ◽  
Nuclear Division Index ◽  
Apoptosis And Necrosis ◽  
Genotoxicity Tests ◽  
Genotoxic Action

Background: The search for novel metallic chemical compounds with toxicogenic effects have been of great importance for more efficient cancer treatment. Objective: The study evaluated the cytotoxic, genotoxic and mutagenic activity of organoteluran RF07 in S-180 cell line. Methods: The bioassays used were cell viability with 3-(4,5-dimethyl-2-thiazole)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) test, evaluation of apoptosis and necrosis using fluorescence and flow cytometry, cytokinesis-block micronucleus test and comet assay. The compound was tested at 1; 2.5 and 5 µM. Results: The results showed the cytotoxicity of RF07 at concentrations of 2.5, 5, 10 and 20 µM when compared to the negative control. For genotoxicity tests, RF07 showed effects in all concentrations assessed by increased index and frequencies of damage and mutagenic alterations. The compound was also cytotoxic due to the significant decrease in nuclear division index, with significant values of apoptosis and necrosis. The results of fluorescence and flow cytometry showed apoptosis as the main type of cell death caused by RF07 at 5 µM, which is thought to avoid an aggressive immune response of the organism. Conclusion: In addition to cytotoxic and genotoxic effects, RF07 creates good perspectives for future antitumor formulations.

scholarly journals ISOLATION OF SPO12–1 AND SPO13–1 FROM A NATURAL VARIANT OF YEAST THAT UNDERGOES A SINGLE MEIOTIC DIVISION

Genetics ◽  
1980 ◽  
Vol 96 (3) ◽  
pp. 567-588 ◽  
Author(s):  
Sue Klapholz ◽  
Rochelle Easton Esposito
Keyword(s):  
Genetic Analysis ◽  
Meiotic Division ◽  
Parental Strain ◽  
Nuclear Division ◽  
Nuclear Genes ◽  
Vegetative Cells ◽  
Total Level ◽  
Natural Variant ◽  
Chromosome Viii

ABSTRACT ATCC4117 is a strain of S. cerevisiae that undergoes a single nuclear division during sporulation to produce asci containing two diploid ascospores (Grewal and Miller 1972). All clones derived from these spores are sporulation-capable and, like the parental strain, form two-spored asci. In this paper, we describe the genetic analysis of ATCC4117. In tetraploid hybrids of vegetative cells of the ATCC4117 diploid and a/a or α/α diploids, the production of two-spored asci is recessive. From these tetraploids, we have isolated two recessive alleles, designated spo12–1 and spo13–1, each of which alone results in the production of asci with two diploid or near-diploid spores. These alleles are unlinked and segregate as single nuclear genes. spo12–1 is approximately 22 cM from its centromere; spo13–1 has been localized to within 1 cM of arg4 on chromosome VIII. This analysis also revealed that ATCC4117 carries a diploidization gene allelic to or closely linked to HO, modifiers that reduce the number of haploid spores per ascus and alleles affecting the total level of sporulation.

scholarly journals A Screen for Genes Involved in the Anaphase Proteolytic Pathway Identifies tsm1+, a Novel Schizosaccharomyces pombe Gene Important for Microtubule Integrity

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1251-1264
Author(s):  
Ekaterina L Grishchuk ◽  
James L Howe ◽  
J Richard McIntosh
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Nuclear Division ◽  
Mitotic Division ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Anaphase Promoting Complex ◽  
Chloromethyl Ketone ◽  
Proteolytic Pathway ◽  
Functional Involvement ◽  
Spindle Elongation

Abstract The growth of several mitotic mutants of Schizosaccharomyces pombe, including nuc2-663, is inhibited by the protease inhibitor N-Tosyl-L-Phenylalanine Chloromethyl Ketone (TPCK). Because nuc2+ encodes a presumptive component of the Anaphase Promoting Complex, which is required for the ubiquitin-dependent proteolysis of certain proteins during exit from mitosis, we have used sensitivity to TPCK as a criterion by which to search for novel S. pombe mutants defective in the anaphase-promoting pathway. In a genetic screen for temperature-sensitive mitotic mutants that were also sensitive to TPCK at a permissive temperature, we isolated three tsm (TPCK-sensitive mitotic) strains. Two of these are alleles of cut1+, but tsm1-512 maps to a novel genetic location. The tsm1-512 mutation leads to delayed nuclear division at restrictive temperatures, apparently as a result of an impaired ability to form a metaphase spindle. After shift of early G2 cells to 36°, tsm1-512 arrests transiently in the second mitotic division and then exits mitosis, as judged by spindle elongation and septation. The chromosomes, however, often fail to segregate properly. Genetic interactions between tsm1-512 and components of the anaphase proteolytic pathway suggest a functional involvement of the Tsm1 protein in this pathway.

Closed spindle nuclear division in the plasmodial phase of the acellular slime moldEchinostelium minutum

PROTOPLASMA ◽  
1980 ◽  
Vol 102 (3-4) ◽  
pp. 235-252 ◽  
Author(s):  
A. A. Hinchee ◽  
E. F. Haskins
Keyword(s):  
Nuclear Division

Direct turgor pressure measurements in individual leaf cells of Tradescantia virginiana

Planta ◽  
1980 ◽  
Vol 149 (5) ◽  
pp. 445-453 ◽  
Author(s):  
U. Zimmermann ◽  
D. H�sken ◽  
E.-D. Schulze
Keyword(s):  
Turgor Pressure ◽  
Pressure Measurements ◽  
Tradescantia Virginiana ◽  
Individual Leaf

scholarly journals The Highly Conserved tRNAHis Guanylyltransferase Thg1p Interacts with the Origin Recognition Complex and Is Required for the G2/M Phase Transition in the Yeast Saccharomyces cerevisiae

2005 ◽  
Vol 4 (4) ◽  
pp. 832-835 ◽  
Author(s):  
Terri S. Rice ◽  
Min Ding ◽  
David S. Pederson ◽  
Nicholas H. Heintz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Origin Recognition Complex ◽  
Nuclear Division ◽  
Permissive Temperature ◽  
Yeast Saccharomyces Cerevisiae ◽  
M Phase ◽  
And Migration ◽  
Origin Recognition

ABSTRACT Here we show that the Saccharomyces cerevisiae tRNAHis guanylyltransferase Thg1p interacts with the origin recognition complex in vivo and in vitro and that overexpression of hemagglutinin-Thg1p selectively impedes growth of orc2-1(Ts) cells at the permissive temperature. Studies with conditional mutants indicate that Thg1p couples nuclear division and migration to cell budding and cytokinesis in yeast.

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