Induction of L-form-like cell shape change of Bacillus subtilis under microculture conditions

Microbiology ◽  
2003 ◽  
Vol 149 (9) ◽  
pp. 2501-2511 ◽  
Author(s):  
Ryuji Shingaki ◽  
Yasuhiro Kasahara ◽  
Megumi Iwano ◽  
Masayoshi Kuwano ◽  
Tomomasa Takatsuka ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cell Shape ◽  
Shape Change ◽  
Cell Protein ◽  
Nitrate Respiration ◽  
Cover Glass ◽  
Whole Cell ◽  
Cell Shape Change ◽  
Whole Cell Protein

A remarkable cell shape change was observed in Bacillus subtilis strain 168 under microculture conditions on CI agar medium (Spizizen's minimal medium supplemented with a trace amount of yeast extract and Casamino acids). Cells cultured under a cover glass changed in form from rod-shaped to spherical, large and irregular shapes that closely resembled L-form cells. The cell shape change was observed only with CI medium, not with Spizizen's minimum medium alone or other rich media. The whole-cell protein profile of cells grown under cover glass and cells grown on CI agar plates differed in several respects. Tandem mass analysis of nine gel bands which differed in protein expression between the two conditions showed that proteins related to nitrate respiration and fermentation were expressed in the shape-changed cells grown under cover glass. The cell shape change of CI cultures was repressed when excess KNO3 was added to the medium. Whole-cell protein analysis of the normal rod-shaped cells grown with 0·1 % KNO3 and the shape-changed cells grown without KNO3 revealed that the expression of the branched-chain α-keto acid dehydrogenase complex (coded by the bfmB gene locus) was elevated in the shape-changed cells. Inactivation of the bfmB locus resulted in the repression of cell shape change, and cells in which bfmB expression was induced by IPTG did show changes in shape. Transmission electron microscopy of ultrathin sections demonstrated that the shape-changed cells had thin walls, and plasmolysis of cells fixed with a solution including 0·1 M sucrose was observed. Clarifying the mechanism of thinning of the cell wall may lead to the development of a new type of cell wall biosynthetic inhibitor.

scholarly journals The evolution of spherical cell shape; progress and perspective

2019 ◽  
Vol 47 (6) ◽  
pp. 1621-1634 ◽  
Author(s):  
Paul Richard Jesena Yulo ◽  
Heather Lyn Hendrickson
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Cell Shape ◽  
Shape Change ◽  
Spherical Cell ◽  
Shape Evolution ◽  
Penicillin Binding Proteins ◽  
Cell Shape Change ◽  
Peptidoglycan Cell Wall ◽  
Bacterial Cell Shape

Bacterial cell shape is a key trait governing the extracellular and intracellular factors of bacterial life. Rod-like cell shape appears to be original which implies that the cell wall, division, and rod-like shape came together in ancient bacteria and that the myriad of shapes observed in extant bacteria have evolved from this ancestral shape. In order to understand its evolution, we must first understand how this trait is actively maintained through the construction and maintenance of the peptidoglycan cell wall. The proteins that are primarily responsible for cell shape are therefore the elements of the bacterial cytoskeleton, principally FtsZ, MreB, and the penicillin-binding proteins. MreB is particularly relevant in the transition between rod-like and spherical cell shape as it is often (but not always) lost early in the process. Here we will highlight what is known of this particular transition in cell shape and how it affects fitness before giving a brief perspective on what will be required in order to progress the field of cell shape evolution from a purely mechanistic discipline to one that has the perspective to both propose and to test reasonable hypotheses regarding the ecological drivers of cell shape change.

The role of microtubules in chick blastoderm expansion—a quantitative study using colchicine

Development ◽  
1975 ◽  
Vol 34 (1) ◽  
pp. 265-277
Author(s):  
J. R. Downie
Keyword(s):  
Cell Division ◽  
Cell Shape ◽  
Shape Change ◽  
Cell Sheet ◽  
Cell Movement ◽  
Vitelline Membrane ◽  
General Context ◽  
Chick Blastoderm ◽  
Cell Shape Change ◽  
Cytoplasmic Microtubules

Since their discovery, cytoplasmic microtubules have been much studied in the context of cell movement and cell shape change. Much of the work has used drugs, particularly colchicine and its relatives, which break down microtubules — the so-called anti-tubulins. Colchicine inhibits the orientated movements of many cell types in vitro, and disrupts cell shape change in several morphogenetic situations. The investigation reported here used chick blastoderm expansion in New culture in an attempt to quantify the colchicine effect on orientated cell movement. However, although colchicine could halt blastoderm expansion entirely, a simple interpretation was not possible. (1) Colchicine at concentrations capable of blocking mitosis, and of disrupting all or most of the cytoplasmic microtubules of the cells studied, inhibited blastoderm expansion, often resulting in an overall retraction of the cell sheet. (2) Though blastoderm expansion does normally involve considerable cell proliferation, the colchicine effect could not be ascribed to a block on cell division since aminopterin, which stops cell division without affecting microtubules, did not inhibit expansion. (3) Blastoderm expansion is effected by the locomotion of a specialized band of edge cells at the blastoderm periphery. These are the only cells normally attached to the vitelline membrane — the substrate for expansion. When most of the blastoderm was excised, leaving the band of edge cells, and the cultures then treated with colchicine, expansion occurred normally. The colchicine effect on blastoderm expansion could not therefore be ascribed to a direct effect on the edge cells. (4) An alternative site of action of the drug is the remaining cells of the blastoderm. These normally become progressively flatter as expansion proceeds. If flattening in these cells is even partially dependent on their cytoplasmic microtubules, disruption of these microtubules might result in the inherent contractility of the cells resisting and eventually halting edge cell migration. That cell shape in these cells is dependent on microtubules was demonstrated by treating flat blastoderm fragments with colchicine. On incubation, the area occupied by these fragments decreased by 25–30 % more than controls. The significance of these results in the general context of orientated cell movements and cell shape determination is discussed, with particular emphasis on the analogous system of Fundulus epiboly.

Autonomy and non-autonomy in Drosophila mesoderm determination and morphogenesis

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 853-859 ◽  
Author(s):  
M. Leptin ◽  
S. Roth
Keyword(s):  
Cell Shape ◽  
Shape Change ◽  
Developmental Program ◽  
Cell Shape Change ◽  
Ventral Furrow ◽  
Large Numbers ◽  
The Individual ◽  
Mutant Cells ◽  
Transplantation Experiments ◽  
Shape Changes

The mesoderm in Drosophila invaginates by a series of characteristic cell shape changes. Mosaics of wild-type cells in an environment of mutant cells incapable of making mesodermal invaginations show that this morphogenetic behaviour does not require interactions between large numbers of cells but that small patches of cells can invaginate independent of their neighbours' behaviour. While the initiation of cell shape change is locally autonomous, the shapes the cells assume are partly determined by the individual cell's environment. Cytoplasmic transplantation experiments show that areas of cells expressing mesodermal genes ectopically at any position in the egg form an invagination. We propose that ventral furrow formation is the consequence of all prospective mesodermal cells independently following their developmental program. Gene expression at the border of the mesoderm is induced by the apposition of mesodermal and non-mesodermal cells.

scholarly journals Tissue tectonics: morphogenetic strain rates, cell shape change and intercalation

2009 ◽  
Vol 6 (6) ◽  
pp. 458-464 ◽  
Author(s):  
Guy B Blanchard ◽  
Alexandre J Kabla ◽  
Nora L Schultz ◽  
Lucy C Butler ◽  
Benedicte Sanson ◽  
...  
Keyword(s):  
Cell Shape ◽  
Shape Change ◽  
Strain Rates ◽  
Cell Shape Change

A dominant inhibitory version of the small GTP-binding protein Rac disrupts cytoskeletal structures and inhibits developmental cell shape changes in Drosophila

Development ◽  
1995 ◽  
Vol 121 (3) ◽  
pp. 903-914 ◽  
Author(s):  
N. Harden ◽  
H.Y. Loh ◽  
W. Chia ◽  
L. Lim
Keyword(s):  
Epidermal Cell ◽  
Cell Shape ◽  
Shape Change ◽  
Yeast Cells ◽  
Cell Shape Change ◽  
Gtp Binding ◽  
Wide Range ◽  
Cell Shape Changes ◽  
Germband Retraction ◽  
Shape Changes

The Rho subfamily of Ras-related small GTP-binding proteins is involved in regulation of the cytoskeleton. The cytoskeletal changes induced by two members of this subfamily, Rho and Rac, in response to growth factor stimulation, have dramatic effects on cell morphology. We are interested in using Drosophila as a system for studying how such effects participate in development. We have identified two Drosophila genes, DRacA and DRacB, encoding proteins with homology to mammalian Rac1 and Rac2. We have made transgenic flies bearing dominant inhibitory (N17DRacA), and wild-type versions of the DRacA cDNA under control of an Hsp70 promoter. Expression of the N17DRacA transgene during embryonic development causes a high frequency of defects in dorsal closure which are due to disruption of cell shape changes in the lateral epidermis. Embryonic expression of N17DRacA also affects germband retraction and head involution. The epidermal cell shape defects caused by expression of N17DRacA are accompanied by disruption of a localized accumulation of actin and myosin thought to be driving epidermal cell shape change. Thus the Rho subfamily may be generating localized changes in the cytoskeleton during Drosophila development in a similar fashion to that seen in mammalian and yeast cells. The Rho subfamily is likely to be participating in a wide range of developmental processes in Drosophila through its regulation of the cytoskeleton.

Collagenase secretion accompanying changes in cell shape occurs only in the presence of a biologically active cytokine

1989 ◽  
Vol 92 (3) ◽  
pp. 473-485
Author(s):  
I. Kuter ◽  
B. Johnson-Wint ◽  
N. Beaupre ◽  
J. Gross
Keyword(s):  
Cell Cultures ◽  
Cell Shape ◽  
Cell Function ◽  
Shape Change ◽  
Biologically Active ◽  
Target Cells ◽  
Mixed Cell ◽  
Cell Shape Change ◽  
Cell Shape Changes ◽  
Shape Changes

We have investigated the relationship between collagenase production, cell shape and stimulatory factors in cell culture. In a homogeneous culture of primary rabbit corneal stromal cells, shape change induced by a variety of agents was not effective in stimulating collagenase secretion. Only in the presence of a biologically active cytokine or phorbol myristate acetate was a correlation seen between changes in cell shape (induced by a second agent) and collagenase secretion by these primary cells. Cell shape changes were not, however, necessary for collagenase secretion, since certain concentrations of endotoxin or lactalbumin hydrolysate effected secretion of the enzyme in the absence of morphological changes. With passaged cells or mixed cell cultures, where cell shape change did correlate with collagenase secretion without the addition of an exogenous agent, the production of an effective cytokine (autocrine or paracrine) was demonstrated. Thus cell shape change seems to be neither universally necessary nor sufficient for the stimulation of collagenase secretion. It is proposed that the function of cytokines may be more immediately related to gene expression in this system than is change in the shape of the cell. The hypothesis is presented that cell shape changes may render the target cells receptive to cytokines, perhaps by replacing the need for a natural cytokine cofactor. It is also demonstrated here that the use of passaged cells, mixed cell cultures containing endogenous cytokine-secreting cells or tissue culture additives can profoundly affect the interpretation of the effect of various agents on collagenase secretion, and may lead to observations that are not directly relevant to cell function in vivo.

Preliminary screening for toxin genes amongst stock cultures of Clostridium perfringens strains isolated from dogs and calves

2014 ◽  
Vol 4 (3) ◽  
pp. 127-132
Author(s):  
Egwari L. O. ◽  
Oghogho E. S. ◽  
Okwumabua O. E. ◽  
Oniha M. I.
Keyword(s):  
Clostridium Perfringens ◽  
Protein Profile ◽  
Animal Origin ◽  
Cell Protein ◽  
Toxin Gene ◽  
Whole Cell ◽  
University Of Wisconsin ◽  
Gene Type ◽  
Whole Cell Protein ◽  
Gene 4

The spectrum of Clostridium perfringens infections ranges from food toxinosis to myonecrosis. In the current study, whole cell protein and toxin gene types were profiled in 12 randomly selected C. perfringens veterinary stock cultures from the University of Wisconsin, Madison to determine epidemio-logical similarity, or diversity amongst strains of animal origin. Whole cell protein analysis was done by SDS-PAGE while toxin gene typing was achieved by extracting DNA by boiling, DNA concentration and purity was determined by spectrophotometer and nanodrop while separation was carried out by checking it on gel electrophoresis. Multiplex PCR was used to identify the toxigenic gene-type. C. perfringens B and C. perfringens EE with established profiles were used as control strains. Isolates typed included strains cp 296, 309, 12872 (from dogs) and 304, 305, 306, 341, 342, 10754, 12218-2, 12218-3, 12473 (from calves). All 12 strains possess the cpa gene, 4 strains have cpb2, 3 strains etx, 2 strains positive for cpe and 1 for cpb. None of the strains carries the itx gene. Two strains have only cpa gene however no strains has more than two toxin gene types, with cpa-cpb2 combination be-ing more frequent. C. perfringens 305 (etx and cpa) and 342 (cpe and cpa) shared the same protein profile but belong to different toxinotype. It is evi-dent that the cpa gene is a marker for all C. perfringens strains, and similarity in protein profile is not sine qua non for toxin gene type.

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