The Modified Flavonol Glycosylation Profile in the Arabidopsis rol1 Mutants Results in Alterations in Plant Growth and Cell Shape Formation

The distinct helical shape of the bacterium Helicobacter Pylori (H. pylori) assists this organism in colonizing the digestive organs of its target host. It has been discovered that a key determinant of helical cell shape formation in H. pylori is the Csd5 protein, which engages in multiple cell shape promoting interactions with the cell wall and other various proteins. This finding has significant clinical implications, as it outlines Csd5 as a potential drug target for treating H. pylori infection in the future.

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Photosynthesis and Heat Response of the Green Alga Micrasterias denticulata (Desmidiaceae)

Zeitschrift für Naturforschung C ◽

10.1515/znc-1999-7-809 ◽

1999 ◽

Vol 54 (7-8) ◽

pp. 508-516 ◽

Cited By ~ 12

Author(s):

Dagmar Weiss ◽

Cornelius Ltitz ◽

Ursula Lütz-Meindl

Keyword(s):

Heat Shock ◽

Green Alga ◽

Cell Shape ◽

Incubation Temperature ◽

Cultivation Temperature ◽

Division Rate ◽

Heat Shocks ◽

Micrasterias Denticulata ◽

Cell Shape Formation ◽

Photosynthesis And Respiration

Abstract Cells of the green alga Micrasterias denticulata cultivated at 15 °C, 20 °C or 25 °C were exposed to heat shocks at different temperatures (30 -40 °C) for varying duration ( 5 - 90 m in). Cell pattern formation, division rate as well as photosynthesis and respiration by measuring oxygen production and consumption have been studied. The degree of cell shape malformations was found dependent on the preceding cultivation temperature along with the mode of the heat shock. Cells cultivated at 15 °C and 20 °C could counteract a 90 min heat shock at 35 °C much better than those cultivated at 25 °C, which was seen by a less reduced young semicell. Cells cultivated at 15 °C and 25 °C reveal a reduced division activity compared to those grown at 20 °C even with a marked retardation when affected by a preceding heat shock. Photosynthesis and the level of plastid pigments (carotenoids, chlorophylls, β-carotene, lutein) of controls determined by HPLC analysis reached a plateau after about 26 days when starting with 22-day old cultures. Photosynthesis and respiration were determined in a range between 15 °C and 40 °C in defined Micrasterias cell cultures of about this age (cultivation temperature 15 °C, 20 °C or 25 °C). Both processes rose steadily with increasing temperature starting with 15 °C and reached peaks between 30 °C and 32 °C, followed by a considerable drop when increasing the incubation temperature up to 40 °C. The experiments reveal that primary processes of energy formation and consumption are much less affected by temperature influences than cell shape formation and division rate

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Arf6 determines tissue architecture by stabilizing intercellular adhesion

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2019.0682 ◽

2020 ◽

Vol 375 (1809) ◽

pp. 20190682 ◽

Cited By ~ 2

Author(s):

Joshua Greig ◽

Natalia A. Bulgakova

Keyword(s):

Cell Shape ◽

Direct Impact ◽

Surface Adhesion ◽

Tissue Architecture ◽

Cortical Actin ◽

Tissue Integrity ◽

Actomyosin Contractility ◽

Cell Shape Formation

Correct cell shape is indispensable for tissue architecture, with cell shape being determined by cortical actin and surface adhesion. The role of adhesion in remodelling tissue is to counteract the deformation of cells by force, resulting from actomyosin contractility, and to maintain tissue integrity. The dynamics of this adhesion are critical to the processes of cell shape formation and maintenance. Here, we show that the trafficking molecule Arf6 has a direct impact on cell elongation, by acting to stabilize E-cadherin-based adhesion complexes at the cell surface, in addition to its canonical role in endocytosis. We demonstrate that these functions of Arf6 are dependent on the molecule Flotillin1, which recruits Arf6 to the plasma membrane. Our data suggest that Arf6 and Flotillin1 operate in a pathway distinct from clathrin-mediated endocytosis. Altogether, we demonstrate that Arf6- and Flotillin1-dependent regulation of the dynamics of cell adhesion contribute to moulding tissue in vivo . This article is part of the discussion meeting issue ‘Contemporary morphogenesis’.

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Modulated polarization microscopy displays the dynamics of cytoskeletal structures in living, motile cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140889 ◽

1995 ◽

Vol 53 ◽

pp. 902-903

Author(s):

J. R. Kuhn ◽

M. Poenie

Keyword(s):

Mitotic Spindle ◽

Actin Filaments ◽

Cell Shape ◽

Dynamic Structure ◽

Living Cells ◽

Cytoskeletal Proteins ◽

Polarization Microscopy ◽

Video Enhancement ◽

Ultrastructural Studies ◽

Motile Cells

Cell shape and movement are controlled by elements of the cytoskeleton including actin filaments an microtubules. Unfortunately, it is difficult to visualize the cytoskeleton in living cells and hence follow it dynamics. Immunofluorescence and ultrastructural studies of fixed cells while providing clear images of the cytoskeleton, give only a static picture of this dynamic structure. Microinjection of fluorescently Is beled cytoskeletal proteins has proved useful as a way to follow some cytoskeletal events, but long terry studies are generally limited by the bleaching of fluorophores and presence of unassembled monomers.Polarization microscopy has the potential for visualizing the cytoskeleton. Although at present, it ha mainly been used for visualizing the mitotic spindle. Polarization microscopy is attractive in that it pro vides a way to selectively image structures such as cytoskeletal filaments that are birefringent. By combing ing standard polarization microscopy with video enhancement techniques it has been possible to image single filaments. In this case, however, filament intensity depends on the orientation of the polarizer and analyzer with respect to the specimen.

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Video Graphics and High-Voltage Electron Microscopy For Analysis of Microtubule Distributions In Fixed Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181373 ◽

1990 ◽

Vol 48 (1) ◽

pp. 524-525

Author(s):

Richard Mcintosh ◽

David Mastronarde ◽

Kent McDonald ◽

Rubai Ding

Keyword(s):

Electron Microscopy ◽

Cross Sections ◽

Cell Shape ◽

Video Camera ◽

Computer Memory ◽

High Voltage Electron Microscopy ◽

Thin Sections ◽

Voltage Electron ◽

Morphogenetic Event ◽

Set Of Points

Microtubules (MTs) are cytoplasmic polymers whose dynamics have an influence on cell shape and motility. MTs influence cell behavior both through their growth and disassembly and through the binding of enzymes to their surfaces. In either case, the positions of the MTs change over time as cells grow and develop. We are working on methods to determine where MTs are at different times during either the cell cycle or a morphogenetic event, using thin and thick sections for electron microscopy and computer graphics to model MT distributions.One approach is to track MTs through serial thin sections cut transverse to the MT axis. This work uses a video camera to digitize electron micrographs of cross sections through a MT system and create image files in computer memory. These are aligned and corrected for relative distortions by using the positions of 8 - 10 MTs on adjacent sections to define a general linear transformation that will align and warp adjacent images to an optimum fit. Two hundred MT images are then used to calculate an “average MT”, and this is cross-correlated with each micrograph in the serial set to locate points likely to correspond to MT centers. This set of points is refined through a discriminate analysis that explores each cross correlogram in the neighborhood of every point with a high correlation score.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600002440 ◽

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.

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