Galvanotaxis of the Plasmodium of Physarum Polycephalum

2012 ◽  
pp. 57-62
Author(s):  
Shuichi Kato
Keyword(s):  
Physarum Polycephalum ◽  
Plasmodium Of Physarum Polycephalum

DEVELOPING PROXIMITY GRAPHS BY PHYSARUM POLYCEPHALUM: DOES THE PLASMODIUM FOLLOW THE TOUSSAINT HIERARCHY?

2009 ◽  
Vol 19 (01) ◽  
pp. 105-127 ◽  
Author(s):  
ANDREW ADAMATZKY
Keyword(s):  
Foraging Behavior ◽  
Delaunay Triangulation ◽  
Spanning Tree ◽  
Physarum Polycephalum ◽  
Minimum Spanning Tree ◽  
Nearest Neighbour ◽  
Minimal Spanning Tree ◽  
Proximity Graphs ◽  
Relative Neighborhood Graph ◽  
Plasmodium Of Physarum Polycephalum

Plasmodium of Physarum polycephalum spans sources of nutrients and constructs varieties of protoplasmic networks during its foraging behavior. When the plasmodium is placed on a substrate populated with sources of nutrients, it spans the sources with protoplasmic network. The plasmodium optimizes the network to deliver efficiently the nutrients to all parts of its body. How exactly does the protoplasmic network unfold during the plasmodium's foraging behavior? What types of proximity graphs are approximated by the network? Does the plasmodium construct a minimal spanning tree first and then add additional protoplasmic veins to increase reliability and through-capacity of the network? We analyze a possibility that the plasmodium constructs a series of proximity graphs: nearest-neighbour graph (NNG), minimum spanning tree (MST), relative neighborhood graph (RNG), Gabriel graph (GG) and Delaunay triangulation (DT). The graphs can be arranged in the inclusion hierarchy (Toussaint hierarchy): NNG ⊆ MST ⊆ RNG ⊆ GG ⊆ DT . We aim to verify if graphs, where nodes are sources of nutrients and edges are protoplasmic tubes, appear in the development of the plasmodium in the order NNG → MST → RNG → GG → DT , corresponding to inclusion of the proximity graphs.

scholarly journals On the Internalisation, Intraplasmodial Carriage and Excretion of Metallic Nanoparticles in the Slime Mould, Physarum Polycephalum

2011 ◽  
Vol 3 (3) ◽  
pp. 1-14 ◽  
Author(s):  
Richard Mayne ◽  
David Patton ◽  
Ben de Lacy Costello ◽  
Andrew Adamatzky ◽  
Rosemary Camilla Patton
Keyword(s):  
Metallic Nanoparticles ◽  
Physarum Polycephalum ◽  
Nutrient Concentration ◽  
Laboratory Experiments ◽  
Micro Scale ◽  
Naked Eye ◽  
High Nutrient ◽  
High Nutrient Concentration ◽  
Silver Metal ◽  
Plasmodium Of Physarum Polycephalum

The plasmodium of Physarum polycephalum is a large single cell visible with the naked eye. When inoculated on a substrate with attractants and repellents the plasmodium develops optimal networks of protoplasmic tubes which span sites of attractants (i.e. nutrients) yet avoid domains with a high nutrient concentration. It should therefore be possible to program the plasmodium towards deterministic adaptive transformation of internalised nano- and micro-scale materials. In laboratory experiments with magnetite nanoparticles and glass micro-spheres coated with silver metal the authors demonstrate that the plasmodium of P. polycephalum can propagate the nano-scale objects using a number of distinct mechanisms including endocytosis, transcytosis and dragging. The results of the authors’ experiments could be used in the development of novel techniques targeted towards the growth of metallised biological wires and hybrid nano- and micro-circuits.

scholarly journals A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia.

1988 ◽  
Vol 8 (3) ◽  
pp. 1275-1281 ◽  
Author(s):  
T G Burland ◽  
E C Paul ◽  
M Oetliker ◽  
W F Dove
Keyword(s):  
Mitotic Spindle ◽  
Physarum Polycephalum ◽  
Fruit Fly ◽  
Beta Tubulin ◽  
Gene Encoding ◽  
Neutral Drift ◽  
Beta 2 ◽  
Restricted Use ◽  
Microtubular Organelles ◽  
Plasmodium Of Physarum Polycephalum

The multinucleate plasmodium of Physarum polycephalum is unusual among eucaryotic cells in that it uses tubulins only in mitotic-spindle microtubules; cytoskeletal, flagellar, and centriolar microtubules are absent in this cell type. We have identified a beta-tubulin cDNA clone, beta 105, which is shown to correspond to the transcript of the betC beta-tubulin locus and to encode beta 2 tubulin, the beta tubulin expressed specifically in the plasmodium and used exclusively in the mitotic spindle. Physarum amoebae utilize tubulins in the cytoskeleton, centrioles, and flagella, in addition to the mitotic spindle. Sequence analysis shows that beta 2 tubulin is only 83% identical to the two beta tubulins expressed in amoebae. This compares with 70 to 83% identity between Physarum beta 2 tubulin and the beta tubulins of yeasts, fungi, alga, trypanosome, fruit fly, chicken, and mouse. On the other hand, Physarum beta 2 tubulin is no more similar to, for example, Aspergillus beta tubulins than it is to those of Drosophila melanogaster or mammals. Several eucaryotes express at least one widely diverged beta tubulin as well as one or more beta tubulins that conform more closely to a consensus beta-tubulin sequence. We suggest that beta-tubulins diverge more when their expression pattern is restricted, especially when this restriction results in their use in fewer functions. This divergence among beta tubulins could have resulted through neutral drift. For example, exclusive use of Physarum beta 2 tubulin in the spindle may have allowed more amino acid substitutions than would be functionally tolerable in the beta tubulins that are utilized in multiple microtubular organelles. Alternatively, restricted use of beta tubulins may allow positive selection to operate more freely to refine beta-tubulin function.

Relation of cytoplasmic calcium to contractility in Physarum polycephalum

1982 ◽  
Vol 53 (1) ◽  
pp. 37-48 ◽  
Author(s):  
R. Kuroda ◽  
H. Kuroda
Keyword(s):  
Electron Microscopy ◽  
Physarum Polycephalum ◽  
Motive Force ◽  
Cytoplasmic Calcium ◽  
Shuttle Streaming ◽  
The Asymmetry ◽  
Plasmodium Of Physarum Polycephalum ◽  
Potassium Pyroantimonate ◽  
Cellular Organelles

In a dumbbell-shaped plasmodium of Physarum polycephalum showing active shuttle streaming Ca was precipitated with potassium pyroantimonate (K[Sb(OH)6]), and the distribution of Ca between the cytoplasm and cellular organelles, especially vacuoles, was examined by electron microscopy. The contracting half-mass, where many empty vacuoles were present, was rich in the small Ca precipitates located in the cytoplasm. The relaxing half-mass, where many Ca-containing vacuoles were present, was poor in the cytoplasmic Ca precipitates. One half-mass of a dumbbell-shaped plasmodium was treated with Ca ionophore, X-537A, and its effect on the motive force for endoplasmic streaming and the distribution of Ca was investigated. The motive force was increased by X-537A, but the period of shuttle streaming was not changed. X-537A also induced a significant increase in the number of the cytoplasmic Ca precipitates in the X-537A-treated contracting half-mass, so that the asymmetry of the distribution of cytoplasmic Ca precipitates was enhanced. A large portion of the vacuoles were empty in the contracting half-mass, and Ca-containing in the relaxing one as in the case of the untreated plasmodium.

scholarly journals THE WORLD'S COLONIZATION AND TRADE ROUTES FORMATION AS IMITATED BY SLIME MOULD

2012 ◽  
Vol 22 (08) ◽  
pp. 1230028 ◽  
Author(s):  
ANDREW ADAMATZKY
Keyword(s):  
Physarum Polycephalum ◽  
Laboratory Experiments ◽  
Metropolitan Areas ◽  
Three Dimensional ◽  
Trade Routes ◽  
Proximity Graphs ◽  
The World ◽  
Transportation Routes ◽  
The Silk Road ◽  
Plasmodium Of Physarum Polycephalum

The plasmodium of Physarum polycephalum is renowned for spanning sources of nutrients with networks of protoplasmic tubes. The networks transport nutrients and metabolites across the plasmodium's body. To imitate a hypothetical colonization of the world and the formation of major transportation routes we cut continents from agar plates arranged in Petri dishes or on the surface of a three-dimensional globe, represent positions of selected metropolitan areas with oat flakes and inoculate the plasmodium in one of the metropolitan areas. The plasmodium propagates towards the sources of nutrients, spans them with its network of protoplasmic tubes and even crosses bare substrate between the continents. From the laboratory experiments we derive weighted Physarum graphs, analyze their structure, compare them with the basic proximity graphs and generalized graphs derived from the Silk Road and the Asia Highway networks.

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