scholarly journals Kinetochore protein depletion underlies cytokinesis failure and somatic polyploidization in the moss Physcomitrella patens

2018 ◽  
Author(s):  
Elena Kozgunova ◽  
Momoko Nishina ◽  
Gohta Goshima
Keyword(s):  
Cell Cycle ◽  
Plant Species ◽  
Physcomitrella Patens ◽  
Plant Cells ◽  
Animal Cells ◽  
Lagging Chromosome ◽  
In The Wild ◽  
Cellular Phenotypes ◽  
Comprehensive Characterization

AbstractLagging chromosome is a hallmark of aneuploidy arising from errors in the kinetochore–spindle attachment in animal cells. However, kinetochore components and cellular phenotypes associated with kinetochore dysfunction are much less explored in plants. Here, we carried out a comprehensive characterization of conserved kinetochore components in the moss Physcomitrella patens and uncovered a distinct scenario in plant cells regarding both the localization and cellular impact of the kinetochore proteins. Most surprisingly, knock-down of several kinetochore proteins led to polyploidy, not aneuploidy, through cytokinesis failure in >90% of the cells that exhibited lagging chromosomes for several minutes or longer. The resultant cells, containing two or more nuclei, proceeded to the next cell cycle and eventually developed into polyploid plants. As lagging chromosomes have been observed in various plant species in the wild, our observation raised a possibility that they could be one of the natural pathways to polyploidy in plants.

scholarly journals Kinetochore protein depletion underlies cytokinesis failure and somatic polyploidization in the moss Physcomitrella patens

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Elena Kozgunova ◽  
Momoko Nishina ◽  
Gohta Goshima
Keyword(s):  
Cell Cycle ◽  
Plant Species ◽  
Physcomitrella Patens ◽  
Plant Cells ◽  
Animal Cells ◽  
Lagging Chromosome ◽  
In The Wild ◽  
Cellular Phenotypes ◽  
Comprehensive Characterization

Lagging chromosome is a hallmark of aneuploidy arising from errors in the kinetochore–spindle attachment in animal cells. However, kinetochore components and cellular phenotypes associated with kinetochore dysfunction are much less explored in plants. Here, we carried out a comprehensive characterization of conserved kinetochore components in the moss Physcomitrella patens and uncovered a distinct scenario in plant cells regarding both the localization and cellular impact of the kinetochore proteins. Most surprisingly, knock-down of several kinetochore proteins led to polyploidy, not aneuploidy, through cytokinesis failure in >90% of the cells that exhibited lagging chromosomes for several minutes or longer. The resultant cells, containing two or more nuclei, proceeded to the next cell cycle and eventually developed into polyploid plants. As lagging chromosomes have been observed in various plant species in the wild, our observation raised a possibility that they could be one of the natural pathways to polyploidy in plants.

scholarly journals Combined microspectrophotometry and automated quantitative autoradiography applied to the analysis of the plant cell cycle

1979 ◽  
Vol 39 (1) ◽  
pp. 235-245
Author(s):  
A.R. Gould
Keyword(s):  
Cell Cycle ◽  
Plant Cells ◽  
Cell Cycle Phase ◽  
Cycle Phase ◽  
Plant Protoplasts ◽  
Animal Cells ◽  
Grain Number ◽  
Virus Particles ◽  
Before And After ◽  
Silver Grains

Two methods, which relate grain number to cell cycle phase in Feulgen-stained autoradiographic preparations, have been developed and compared. Both methods automate grain number estimations, one by taking integrated absorbance measurements at different wavelengths, the other by measuring absorption at a single wavelength before and after chemical removal of silver grains. With tritium-labelled tobacco mosaic virus as a probe, a quantitative analysis has been made of the binding of virus particles to plant protoplasts in different compartments of the DNA replication and partition cycle. The preliminary results indicate that the quantity of virus bound by protoplasts is related to their cell cycle phase. Whilst in this case, the methods have been used with plant cells, both techniques are equally applicable to animal cells.

scholarly journals Characterization of a Drosophila Centrosome Protein CP309 That Shares Homology with Kendrin and CG-NAP

2004 ◽  
Vol 15 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Shin-ichi Kawaguchi ◽  
Yixian Zheng
Keyword(s):  
Cell Cycle ◽  
Drosophila Melanogaster ◽  
Coiled Coil ◽  
Animal Cells ◽  
Microtubule Nucleation ◽  
Small Complex ◽  
Biochemical Studies ◽  
Ring Complex ◽  
Centrosome Protein

The centrosome in animal cells provides a major microtubule-nucleating site that regulates the microtubule cytoskeleton temporally and spatially throughout the cell cycle. We report the identification in Drosophila melanogaster of a large coiled-coil centrosome protein that can bind to calmodulin. Biochemical studies reveal that this novel Drosophila centrosome protein, centrosome protein of 309 kDa (CP309), cofractionates with the γ-tubulin ring complex and the centrosome-complementing activity. We show that CP309 is required for microtubule nucleation mediated by centrosomes and that it interacts with the γ-tubulin small complex. These findings suggest that the microtubule-nucleating activity of the centrosome requires the function of CP309.

scholarly journals Cytokinesis in Eukaryotes

2002 ◽  
Vol 66 (2) ◽  
pp. 155-178 ◽  
Author(s):  
David A. Guertin ◽  
Susanne Trautmann ◽  
Dannel McCollum
Keyword(s):  
Genetic Model ◽  
Plant Cells ◽  
Complex Problem ◽  
Model Organisms ◽  
Animal Cells ◽  
Contractile Ring ◽  
Daughter Cells ◽  
Intense Research

SUMMARY Cytokinesis is the final event of the cell division cycle, and its completion results in irreversible partition of a mother cell into two daughter cells. Cytokinesis was one of the first cell cycle events observed by simple cell biological techniques; however, molecular characterization of cytokinesis has been slowed by its particular resistance to in vitro biochemical approaches. In recent years, the use of genetic model organisms has greatly advanced our molecular understanding of cytokinesis. While the outcome of cytokinesis is conserved in all dividing organisms, the mechanism of division varies across the major eukaryotic kingdoms. Yeasts and animals, for instance, use a contractile ring that ingresses to the cell middle in order to divide, while plant cells build new cell wall outward to the cortex. As would be expected, there is considerable conservation of molecules involved in cytokinesis between yeast and animal cells, while at first glance, plant cells seem quite different. However, in recent years, it has become clear that some aspects of division are conserved between plant, yeast, and animal cells. In this review we discuss the major recent advances in defining cytokinesis, focusing on deciding where to divide, building the division apparatus, and dividing. In addition, we discuss the complex problem of coordinating the division cycle with the nuclear cycle, which has recently become an area of intense research. In conclusion, we discuss how certain cells have utilized cytokinesis to direct development.

scholarly journals Rounding up plant cells

2010 ◽  
Vol 1 (1) ◽  
pp. 8 ◽  
Author(s):  
Sergio Ochatt ◽  
Anne Moessner
Keyword(s):  
Flow Cytometry ◽  
Cell Shape ◽  
Plant Cells ◽  
Morphometric Study ◽  
Animal Cells ◽  
General Applicability ◽  
Flour Quality ◽  
Shape Coefficient ◽  
Pisum Sativum L

Compared to animal cells, plant cells are typically non-spherical, which may bias morphometric and fluorimetric analyses, including flow cytometry and other approaches used in the study of cellular biodiversity. The morphometric study of cotyledonary cells may serve to distinguish between genotypes, as cell shape is clearly an important issue when assessing flour quality and seed digestibility by animals, being affected by the surface and volume of particles. We devised a shape coefficient that resolves these difficulties with pea (Pisum sativum L.), and may find general applicability in cytological studies and for the characterization of biodiversity patterns.

scholarly journals Molecular and cytogenetic assessment of Dipterygium glaucum genotoxicity

2016 ◽  
Vol 88 (suppl 1) ◽  
pp. 623-634 ◽  
Author(s):  
NADA H. ALTWATY ◽  
OSAMA E. EL-SAYED ◽  
NARIMAN A.H. ALY ◽  
MOHAMED N. BAESHEN ◽  
NABIH A. BAESHEN
Keyword(s):  
Plant Species ◽  
Chromosomal Abnormalities ◽  
Herbal Remedy ◽  
Biological Activities ◽  
Cancer Cell Line ◽  
Toxicity Tests ◽  
Animal Cells ◽  
Herbal Products ◽  
Produce Safety ◽  
Lagging Chromosome

ABSTRACT The aim of the present study is to assess the genotoxicity of Dipterygium glaucum grows widely in Saudi Arabia desert to produce safety herbal products. This work is considered the first and pioneer report so far due to the lack and poor evaluated reports of the plant species for their mutagensity, genotoxicity and cytogenetics effects. Cytogenetic effects of D. glaucum on mitotic in roots of Vicia faba showed reduction in mitotic activity using three extracts; water, ethanol and ethyl acetate. Chromosomal abnormalities were recorded that included stickiness of chromosomes, chromatin bridge, fragments, lagging chromosome and micronuclei. Protein bands and RAPD analyses of V. faba treated with three D. glaucum extracts revealed some newly induced proteins and DNA fragments and other disappeared. Chemical constitution of the plant species should be identified with their biological activities against human and animal cells like HeLa cancer cell line. We are recommending using additional genotoxicity tests and other toxicity tests on animal culture with different concentrations and also utilizing several drought and heat tolerant genes of the plant species in gene cloning to develop and improve other economical crop plants instead of using the species as oral herbal remedy

scholarly journals The plant Spc98p homologue colocalizes with γ-tubulin at microtubule nucleation sites and is required for microtubule nucleation

2002 ◽  
Vol 115 (11) ◽  
pp. 2423-2431 ◽  
Author(s):  
Mathieu Erhardt ◽  
Virginie Stoppin-Mellet ◽  
Sarah Campagne ◽  
Jean Canaday ◽  
Jérôme Mutterer ◽  
...  
Keyword(s):  
Spindle Pole Body ◽  
Plant Cells ◽  
Spindle Pole ◽  
Cell Cortex ◽  
Nuclear Surface ◽  
Animal Cells ◽  
Microtubule Nucleation ◽  
Higher Plant ◽  
Nucleation Sites

The molecular basis of microtubule nucleation is still not known in higher plant cells. This process is better understood in yeast and animals cells. In the yeast spindle pole body and the centrosome in animal cells,γ-tubulin small complexes and γ-tubulin ring complexes,respectively, nucleate all microtubules. In addition to γ-tubulin,Spc98p or its homologues plays an essential role. We report here the characterization of rice and Arabidopsis homologues of SPC98. Spc98p colocalizes with γ-tubulin at the nuclear surface where microtubules are nucleated on isolated tobacco nuclei and in living cells. AtSpc98p-GFP also localizes at the cell cortex. Spc98p is not associated with γ-tubulin along microtubules. These data suggest that multiple microtubule-nucleating sites are active in plant cells. Microtubule nucleation involving Spc98p-containing γ-tubulin complexes could then be conserved among all eukaryotes, despite differences in structure and spatial distribution of microtubule organizing centers.

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