scholarly journals Meiotic transmission of epigenetic changes in the cell-division factor requirement of plant cells

Development ◽  
2003 ◽  
Vol 130 (25) ◽  
pp. 6201-6208 ◽  
Author(s):  
F. Meins
Keyword(s):  
Cell Division ◽  
Plant Cells ◽  
Epigenetic Changes ◽  
Division Factor ◽  
Meiotic Transmission

Confocal microscopy of the cytoskeleton in living plant cells following microinjection of fluorescent probes

1993 ◽  
Vol 51 ◽  
pp. 130-131
Author(s):  
Ann Cleary
Keyword(s):  
Cell Division ◽  
Fluorescent Probes ◽  
Actin Filaments ◽  
Intracellular Transport ◽  
Cell Structure ◽  
Plant Cells ◽  
Cell Plate ◽  
Cell Cortex ◽  
Living Plant ◽  
Rhodamine Phalloidin

Microinjection of fluorescent probes into living plant cells reveals new aspects of cell structure and function. Microtubules and actin filaments are dynamic components of the cytoskeleton and are involved in cell growth, division and intracellular transport. To date, cytoskeletal probes used in microinjection studies have included rhodamine-phalloidin for labelling actin filaments and fluorescently labelled animal tubulin for incorporation into microtubules. From a recent study of Tradescantia stamen hair cells it appears that actin may have a role in defining the plane of cell division. Unlike microtubules, actin is present in the cell cortex and delimits the division site throughout mitosis. Herein, I shall describe actin, its arrangement and putative role in cell plate placement, in another material, living cells of Tradescantia leaf epidermis.The epidermis is peeled from the abaxial surface of young leaves usually without disruption to cytoplasmic streaming or cell division. The peel is stuck to the base of a well slide using 0.1% polyethylenimine and bathed in a solution of 1% mannitol +/− 1 mM probenecid.

scholarly journals Cell Cycle-Specific Disruption of the Preprophase Band of Microtubules in Fern Protonemata: Effects of Displacement of the Endoplasm by Centrifugation

1992 ◽  
Vol 101 (1) ◽  
pp. 93-98 ◽  
Author(s):  
TAKASHI MURATA ◽  
MASAMITSU WADA
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Plant Cells ◽  
Preprophase Band ◽  
Higher Plant ◽  
The Future ◽  
Prophase Nucleus ◽  
Original Region ◽  
Fern Protonemata

The preprophase band (PPB) of microtubules (MTs), which appears at the future site of cytokinesis prior to cell division in higher plant cells, disappears by metaphase. Recent studies have shown that displacement of the endoplasm from the PPB region by centrifugation delays the disappearance of the PPB. To study the role of the endoplasm in the cell cycle-specific disruption of the PPB, the filamentous protonemal cells of the fern Adiantum capilius-veneris L. were centrifuged twice so that the first centrifugation displaced the endoplasm from the site of the PPB and the second returned it to its original location. The endoplasm, including the nucleus of various stages of mitosis, could be returned by the second centrifugation to the original region of the PPB, which persists during mitosis in the centrifuged cells. When endoplasm with a prophase nucleus was returned to its original location, the PPB was not disrupted. When endoplasm with a prometa-phase telophase nucleus was similarly returned, the PPB was disrupted within 10 min of termination of centrifugation. In protonemal cells of Adiantum, a second PPB is often formed near the displaced nucleus after the first centrifugation. In cells in which the endoplasm was considered to have been returned to its original location at the prophase/prometaphase transition, the second PPB did not disappear even though the initial PPB was disrupted by the endoplasm. These results suggest that cell cycle-specific disruption of the PPB is regulated by some factor(s) in the endoplasm, which appears at prometaphase, i.e. the stage at which the PPB is disrupted in non-centrifuged cells.

The cell cycle of symbiotic Chlorella. I. The relationship between host feeding and algal cell growth and division

1985 ◽  
Vol 77 (1) ◽  
pp. 225-239
Author(s):  
P.J. McAuley
Keyword(s):  
Cell Division ◽  
Cell Growth ◽  
Host Cell ◽  
Algal Cell ◽  
Host Cells ◽  
Digestive Cell ◽  
Host Feeding ◽  
Digestive Cells ◽  
Division Factor ◽  
Cell Mitosis

When green hydra were starved, cell division of the symbiotic algae within their digestive cells was inhibited, but algal cell growth, measured as increase in either mean volume or protein content per cell, was not. Therefore, control of algal division by the host digestive cells must be effected by direct inhibition of algal mitosis rather than by controlling algal cell growth. The number of algae per digestive cell increased slightly during starvation, eventually reaching a new stable level. A number of experiments demonstrated that although there was a relationship between host cell and algal mitosis, this was not causal: the apparent entrainment of algal mitosis to that of the host cells could be disrupted. Thus, there was a delay in algal but not host cell mitosis when hydra were fed after prolonged starvation, and algae repopulated starved hydra with lower than normal numbers of algae (reinfected aposymbionts or hydra transferred to light after growth in continuous darkness). Two experiments demonstrated a direct stimulation of algal cell division by host feeding. Relationships of algal and host cell mitosis to numbers of Artemia digested per hydra were different, and in hydra fed extracted Artemia algal, but not host cell, mitosis was reduced in comparison to that in control hydra fed live shrimp. It is proposed that algal division may be dependent on a division factor, derived from host digestion of prey, whose supply is controlled by the host cells. Numbers of algae per cell would be regulated by competition for division factor, except at host cell mitosis, when the algae may have temporarily uncontrolled access to host pools of division factor. The identity of the division factor is not known, but presumably is a metabolite needed by both host cells and algae.

Cell size of proliferating plant cells increases with temperature: Implications in the control of cell division

1989 ◽  
Vol 185 (1) ◽  
pp. 277-282 ◽  
Author(s):  
Antonio Cuadrado ◽  
Matilde H. Navarrete ◽  
Jose L. Canovas
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Plant Cells

A novel cell division factor from tobacco 2B-13 cells that induced cell division in auxin-starved tobacco BY-2 cells

2006 ◽  
Vol 93 (6) ◽  
pp. 278-285 ◽  
Author(s):  
Takashi Shimizu ◽  
Kentaro Eguchi ◽  
Ikuo Nishida ◽  
Kris Laukens ◽  
Erwin Witters ◽  
...  
Keyword(s):  
Cell Division ◽  
Division Factor

Pseudodirected variation in the requirement of cultured plant cells for cell-division factors

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1163-1168
Author(s):  
F. Meins ◽  
M. Seldran
Keyword(s):  
Cell Division ◽  
Phenotypic Variation ◽  
Quantitative Method ◽  
Somatic Mutations ◽  
Plant Cells ◽  
Tissue Level ◽  
C Cells ◽  
Cytokinin Action ◽  
Selection Of ◽  
Cells Cultured

Cells cultured from explants of tobacco leaf require exogenous cell-division factors such as the cytokinin kinetin for sustained proliferation. When cytokinin-requiring (C-) cells are cultured on medium containing 1/100 the optimum cytokinin concen tration they rapidly give rise to cytokinin-autotrophic (C+) variants. Some of these variants result from a meiotically transmitted change at the Habituated leaf-2 locus. We measured the rate of phenotypic variation by a simple, quantitative method and found that cultured tobacco cells alternate between the C- and C+ states at extremely high rates of approx. 10–2 per cell generation, which is 102- to 103-fold more rapid than most somatic mutations in tobacco. These changes are so rapid that the cla ssical distinction between random and induced events is blurred. Selection of alternate phenotypes arising by rapid, reversible cellular variation results in changes that appear to be directed at the tissue level. This phenomenon, called pseudodirected variation, is of particular interest because it suggests novel stochastic mechanisms of cytokinin action and a plausible explanation for the directed, but plastic nature of development in plants.

How does the cytoskeleton read the laws of geometry in aligning the division plane of plant cells?

Development ◽  
1991 ◽  
Vol 113 (Supplement_1) ◽  
pp. 55-65 ◽  
Author(s):  
Clive W. Lloyd
Keyword(s):  
Cell Division ◽  
Plant Tissue ◽  
Plant Cells ◽  
Cell Plate ◽  
Cross Wall ◽  
Minimal Path ◽  
Neighbouring Cell ◽  
Robert Hooke ◽  
Division Plane ◽  
Geometrical Properties

Since Robert Hooke observed the froth-like texture of sectioned plant tissue, there have been numerous attempts to describe the geometrical properties of cells and to account for the patterns they form. Some aspects of biological patterning can be mimicked by compressed spheres and by liquid foams, implying that compression or surface tension are physical bases of patterning. The 14-sided semi-regular tetrakaidecahedron encloses a given volume most efficiently and packs to fill space. However, observations of real plant tissue (and of soap bubbles) in the first half of this century established that plant cells only rarely form this mathematically ideal figure composed predominantly of 6-sided polygons. Instead, they tend to form a topologically transformed variant having mainly pentagonal faces although there is variability in the number of sides and the angles formed. But the one irreducible component of normal cell and tissue geometry is that only three edges meet at a point in a plane. In solid space, this gives rise to tetrahedral junctions and it is from this that certain limitations on sidedness flow. For three edges to meet at a point means that there must be an avoidance mechanism which prevents a new cell plate from aligning with an existing 3-way junction. Sinnott and Bloch (1940) saw that the cytoplasmic strands which precede the cell plate, predicted its alignment and also avoided 3-way junctions in unwounded tissues. Recently, F-actin and microtubules have been detected in these pre-mitotic, transvacuolar strands. The question considered here is why those cytoskeletal elements avoid aligning with the vertex where a neighbouring cross wall has already joined the mother wall. An hypothesis is discussed in which tensile strands – against a background of cortical re-organization during pre-mitosis – tend to seek the minimal path between nucleus and cortex. In this way, it is suggested that unstable strands are gradually drawn into a transvacuolar baffle (the phragmosome) within which cell division occurs. Vertices are avoided by the strands because they constitute unfavoured longer paths. The demonstrable tendency of tensile strands to contact mother walls perpendicularly would seem to account for Hofmeister's and Sachs' rules involving right-angled junctions. As others have discussed, such right-angled junctions give way to co-equal 120° angles between the three walls during subsequent cell growth. It is this asynchrony of cell division – where attachment of a cell plate causes the neighbouring wall to buckle – that forms a vertex to be avoided by subsequent pre-mitotic strands in that neighbouring cell. In this way, successive division planes would not co-align. It is therefore suggested that the exceptional formation of 4-way junctions in wounded tissue results from the fact that adjacent cells divide simultaneously; the lack of prebuckling of a common wall under these circumstances means that there is no vertex to be avoided by the minimal path mechanism.

Creative young minds plus serendipity — a recipe for science

Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 443-451 ◽  
Author(s):  
Larry Fowke
Keyword(s):  
Cell Division ◽  
Academic Career ◽  
Algal Cell ◽  
Plant Cells ◽  
Faculty Position ◽  
Plant Cell Division ◽  
International Collaborations ◽  
Postdoctoral Research ◽  
And Function ◽  
The Impact

The author highlights his 40-year academic career with emphasis on the major contributions of technicians, graduate students, and postdoctoral fellows in his research laboratory. Postdoctoral research in Canberra, Australia, on algal cell division preceded a faculty position in the Biology Department, University of Saskatchewan, that stretched from 1970 until today. Early work in Saskatoon that focused on cultured plant cells and protoplasts developed into an investigation of the structure and function of plant coated vesicles. A short sabbatical in Sweden resulted in a 15-year research program on somatic embryogenesis in conifers. A return to the study of cell division over the last 10 plus years resulted in the discovery and analysis of a family of plant cell division inhibitors. The author’s story emphasizes the importance of having motivated and creative scientists in the laboratory, but also recognizes the impact of serendipity. International collaborations are also featured.

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