Experimental and ultrastructural studies on cell shape formation in the defect mutant cellmicrasterias thomasiana f. uniradiata

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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Newly Discovered Cell Shape Promoting Protein Complex Involved in the Maintenance of Distinct Helical Shape of Helicobacter Pylori

Sciential - McMaster Undergraduate Science Journal ◽

10.15173/sciential.v1i2.2132 ◽

2019 ◽

pp. 28-30

Author(s):

Freeman Paczkowski

Keyword(s):

Cell Wall ◽

Helicobacter Pylori ◽

Cell Shape ◽

Drug Target ◽

Clinical Implications ◽

Potential Drug Target ◽

Potential Drug ◽

Multiple Cell ◽

H Pylori ◽

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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Electron Tomography in the Study of Bacterial Structure and Function

Microscopy Today ◽

10.1017/s1551929500050811 ◽

2005 ◽

Vol 13 (1) ◽

pp. 22-25

Author(s):

Kenneth H. Downing ◽

Haixin Sui ◽

Luis R. Comolli ◽

Hoi-Ying Holman

Keyword(s):

Cell Division ◽

Cell Shape ◽

Electron Tomography ◽

Structure And Function ◽

Interacting Proteins ◽

Ultrastructural Studies ◽

Division Site ◽

Metabolic Functions ◽

Bacterial Structure ◽

And Function

Bacteria contain a wealth of mechanisms that organize their internal and external components into a highly polar structure, frequently with distinctive shape, and constrain certain metabolic functions to particular parts of the cell. For example, cell division generally takes place at the middle of the cell, and a host of interacting proteins are involved in ensuring that the division site is positioned properly. Thus, in spite of the lingering perception among some scientists that these cells are simply bags of freely diffusing enzymes, there is much to be learned from ultrastructural studies. Light microscopy has given evidence of cytoskeletal components that presumably establish and maintain cell shape and participate in cell division.

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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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Ultrastructure of Cercarial Tails

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050913 ◽

1974 ◽

Vol 32 ◽

pp. 180-181

Author(s):

Richard S. Demaree ◽

Donald M. Wootton

Keyword(s):

Schistosoma Japonicum ◽

Intermediate Hosts ◽

Suitable Host ◽

Ultrastructural Studies ◽

Tail Structure

Cercariae (juvenile trematodes with tails) emerge from mollusk intermediate hosts and swim toward definitive hosts or encystment objects. The locomotor power is furnished by the tail. Upon reaching a suitable host or encystment object, the tail is cast off and the cercariae penetrate and/or encyst. Ultrastructural studies of cercariae are sparse. There is even lessUltrastructural studies of cercariae are sparse. There is even less information about the tail structure; and body-to-tail morphology has been documented only for Acanthatrium oregonense and Schistosoma japonicum.

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