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 Cytoskeletal organization in isolated plant cells under geometry control

2020 ◽  
Vol 117 (29) ◽  
pp. 17399-17408 ◽  
Author(s):  
Pauline Durand-Smet ◽  
Tamsin A. Spelman ◽  
Elliot M. Meyerowitz ◽  
Henrik Jönsson
Keyword(s):  
Cell Shape ◽  
Flexural Rigidity ◽  
Persistence Length ◽  
Plant Cells ◽  
Cytoskeletal Proteins ◽  
Three Dimensions ◽  
Animal Cells ◽  
Living Plant ◽  
Cytoskeletal Organization ◽  
Actin Organization

The cytoskeleton plays a key role in establishing robust cell shape. In animals, it is well established that cell shape can also influence cytoskeletal organization. Cytoskeletal proteins are well conserved between animal and plant kingdoms; nevertheless, because plant cells exhibit major structural differences to animal cells, the question arises whether the plant cytoskeleton also responds to geometrical cues. Recent numerical simulations predicted that a geometry-based rule is sufficient to explain the microtubule (MT) organization observed in cells. Due to their high flexural rigidity and persistence length of the order of a few millimeters, MTs are rigid over cellular dimensions and are thus expected to align along their long axis if constrained in specific geometries. This hypothesis remains to be testedin cellulo. Here, we explore the relative contribution of geometry to the final organization of actin and MT cytoskeletons in single plant cells ofArabidopsis thaliana. We show that the cytoskeleton aligns with the long axis of the cells. We find that actin organization relies on MTs but not the opposite. We develop a model of self-organizing MTs in three dimensions, which predicts the importance of MT severing, which we confirm experimentally. This work is a first step toward assessing quantitatively how cellular geometry contributes to the control of cytoskeletal organization in living plant cells.

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.

Label-Free and Simultaneous Mechanical and Electrical Characterization of Single Plant Cells Using Microfluidic Impedance Flow Cytometry

2020 ◽  
Vol 92 (21) ◽  
pp. 14568-14575
Author(s):  
Ziyu Han ◽  
Lincai Chen ◽  
Shuaihua Zhang ◽  
Jiehua Wang ◽  
Xuexin Duan
Keyword(s):  
Flow Cytometry ◽  
Plant Cells ◽  
Electrical Characterization ◽  
Label Free ◽  
Single Plant

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 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.

Characterization of a Motile Cellular Domain Arising During the Amoebo-Flagellate Transformation of Physarum Polycephalum

1980 ◽  
Vol 38 ◽  
pp. 552-553
Author(s):  
K.I. Pagh ◽  
M.R. Adelman
Keyword(s):  
Cell Shape ◽  
Physarum Polycephalum ◽  
Slime Mold ◽  
Live Cells ◽  
Cellular Domain

Unicellular amoebae of the slime mold Physarum polycephalum undergo marked changes in cell shape and motility during their conversion into flagellate swimming cells (l). To understand the processes underlying motile activities expressed during the amoebo-flagellate transformation, we have undertaken detailed investigations of the organization, formation and functions of subcellular structures or domains of the cell which are hypothesized to play a role in movement. One focus of our studies is on a structure, termed the “ridge” which appears as a flattened extension of the periphery along the length of transforming cells (Fig. 1). Observations of live cells using Nomarski optics reveal two types of movement in this region:propagation of undulations along the length of the ridge and formation and retraction of filopodial projections from its edge. The differing activities appear to be associated with two characteristic morphologies, illustrated in Fig. 1.

scholarly journals KD determination from time-resolved experiments on live cells with LigandTracer and reconciliation with end-point flow cytometry measurements

2021 ◽  
Author(s):  
Diana Spiegelberg ◽  
Jonas Stenberg ◽  
Pascale Richalet ◽  
Marc Vanhove
Keyword(s):  
Flow Cytometry ◽  
Live Cells ◽  
Time Resolved ◽  
Surface Receptors ◽  
Full Characterization ◽  
End Point ◽  
Titration Curves ◽  
Kinetics Of

AbstractDesign of next-generation therapeutics comes with new challenges and emulates technology and methods to meet them. Characterizing the binding of either natural ligands or therapeutic proteins to cell-surface receptors, for which relevant recombinant versions may not exist, represents one of these challenges. Here we report the characterization of the interaction of five different antibody therapeutics (Trastuzumab, Rituximab, Panitumumab, Pertuzumab, and Cetuximab) with their cognate target receptors using LigandTracer. The method offers the advantage of being performed on live cells, alleviating the need for a recombinant source of the receptor. Furthermore, time-resolved measurements, in addition to allowing the determination of the affinity of the studied drug to its target, give access to the binding kinetics thereby providing a full characterization of the system. In this study, we also compared time-resolved LigandTracer data with end-point KD determination from flow cytometry experiments and hypothesize that discrepancies between these two approaches, when they exist, generally come from flow cytometry titration curves being acquired prior to full equilibration of the system. Our data, however, show that knowledge of the kinetics of the interaction allows to reconcile the data obtained by flow cytometry and LigandTracer and demonstrate the complementarity of these two methods.

Polarized light-scattering profile-advanced characterization of nonspherical particles with scanning flow cytometry

2011 ◽  
Vol 79A (7) ◽  
pp. 570-579 ◽  
Author(s):  
Dmitry I. Strokotov ◽  
Alexander E. Moskalensky ◽  
Vyacheslav M. Nekrasov ◽  
Valeri P. Maltsev
Keyword(s):  
Flow Cytometry ◽  
Light Scattering ◽  
Polarized Light ◽  
Advanced Characterization ◽  
Nonspherical Particles

scholarly journals Adaptation of a retrovirus as a eucaryotic vector transmitting the herpes simplex virus thymidine kinase gene.

1982 ◽  
Vol 2 (4) ◽  
pp. 426-436 ◽  
Author(s):  
C J Tabin ◽  
J W Hoffmann ◽  
S P Goff ◽  
R A Weinberg
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Thymidine Kinase ◽  
Dna Sequences ◽  
Leukemia Virus ◽  
Chimeric Virus ◽  
Animal Cells ◽  
Kinase Gene ◽  
General Applicability ◽  
Simplex Virus

We investigated the feasibility of using retroviruses as vectors for transferring DNA sequences into animal cells. The thymidine kinase (tk) gene of herpes simplex virus was chosen as a convenient model. The internal BamHI fragments of a DNA clone of Moloney leukemia virus (MLV) were replaced with a purified BamHI DNA segment containing the tk gene. Chimeric genomes were created carrying the tk insert in both orientations relative to the MLV sequence. Each was transfected into TK- cells along with MLV helper virus, and TK+ colonies were obtained by selection in the presence of hypoxanthine, aminopterin, and thymidine (HAT). Virus collected from TK+-transformed, MLV producer cells passed the TK+ phenotype to TK- cells. Nonproducer cells were isolated, and TK+ transducing virus was subsequently rescued from them. The chimeric virus showed single-hit kinetics in infections. Virion and cellular RNA and cellular DNA from infected cells were all shown to contain sequences which hybridized to both MLV- and tk-specific probes. The sizes of these sequences were consistent with those predicted for the chimeric virus. In all respects studied, the chimeric MLV-tk virus behaved like known replication-defective retroviruses. These experiments suggest great general applicability of retroviruses as eucaryotic vectors.

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