CHANGES IN cAMP AND cGMP CONCENTRATION, BIREFRINGENT FIBRILS AND CONTRACTILE ACTIVITY ACCOMPANYING UV AND BLUE LIGHT PHOTOAVOIDANCE IN PLASMODIA OF AN ALBINO STRAIN OF Physarum polycephalum

1988 ◽  
Vol 47 (2) ◽  
pp. 271-275 ◽  
Author(s):  
Tetsuo Ueda ◽  
Yoshthito Mori ◽  
Toshiyuki Nakagaki ◽  
Yonosuke Kobatake
Keyword(s):  
Blue Light ◽  
Physarum Polycephalum ◽  
Contractile Activity ◽  
Birefringent Fibrils ◽  
Camp And Cgmp ◽  
Albino Strain

The blue-light reaction in plasmodia of Physarum polycephalum is coupled to respiration

Planta ◽  
1983 ◽  
Vol 158 (1) ◽  
pp. 54-62 ◽  
Author(s):  
W. Korohoda ◽  
Z. Shraideh ◽  
Z. Baranowski ◽  
K. E. Wohlfarth-Bottermann
Keyword(s):  
Blue Light ◽  
Physarum Polycephalum ◽  
Light Reaction

scholarly journals THE CHANGING PATTERN OF BIREFRINGENCE IN PLASMODIA OF THE SLIME MOLD, PHYSARUM POLYCEPHALUM

1965 ◽  
Vol 25 (2) ◽  
pp. 361-374 ◽  
Author(s):  
Hiromichi Nakajima ◽  
Robert D. Allen
Keyword(s):  
Physarum Polycephalum ◽  
Cytoplasmic Streaming ◽  
Channel Wall ◽  
Polarized Light ◽  
Orthogonal Arrays ◽  
Slime Mold ◽  
Wall Material ◽  
Shuttle Streaming ◽  
Oriented Parallel ◽  
Birefringent Fibrils

Plasmodia of the acellular slime mold, Physarum polycephalum, reveal a complex and changing pattern of birefringence when examined with a sensitive polarizing microscope. Positively birefringent fibrils are found throughout the ectoplasmic region of the plasmodium. In the larger strands they may be oriented parallel to the strand axis, or arranged circularly or spirally along the periphery of endoplasmic channels. Some fibrils exist for only a few minutes, others for a longer period. Some, particularly the circular fibrils, undergo changes in birefringence as they undergo cyclic deformations. In the ramifying strand region and the advancing margin there is a tendency for fibrils of various sizes to become organized into mutually orthogonal arrays. In some plasmodia the channel wall material immediately adjacent to the endoplasm has been found to be birefringent. The sign of endoplasmic birefringence is negative, and its magnitude is apparently constant over the streaming cycle. The pattern of plasmodial birefringence and its changes during the shuttle streaming cycle of Physarum are considered in the light of several models designed to explain either cytoplasmic streaming alone or the entire gamut of plasmodial motions. The results of this and other recent physical studies suggest that both streaming and the various other motions of the plasmodium may very likely be explained in terms of coordinated contractions taking place in the fibrils which are rendered visible in polarized light.

scholarly journals An Optical Method for Monitoring Contractile Activity in the Plasmodia of Physarum polycephalum

1980 ◽  
Vol 5 (3) ◽  
pp. 281-284 ◽  
Author(s):  
Tatsumi Hirose ◽  
Tetsuo Ueda ◽  
Yonosuke Kobatake
Keyword(s):  
Optical Method ◽  
Physarum Polycephalum ◽  
Contractile Activity

Interrelation between respiratory and contractile activity of Physarum polycephalum

2017 ◽  
Vol 50 (22) ◽  
pp. 224003 ◽  
Author(s):  
T I Avsievich ◽  
S V Frolov ◽  
S G Proskurin
Keyword(s):  
Physarum Polycephalum ◽  
Contractile Activity

Ca-Histochemistry in slime mold plasmodia

1978 ◽  
Vol 36 (2) ◽  
pp. 130-131
Author(s):  
Ulrich Dierkes
Keyword(s):  
Physarum Polycephalum ◽  
Carbon Coating ◽  
Freeze Drying ◽  
Freeze Fracture ◽  
Freeze Substitution ◽  
Uranyl Acetate ◽  
Slime Mold ◽  
Staining Procedure ◽  
Protoplasmic Streaming ◽  
Intracellular Ca

Calcium is supposed to play an important role in the control of protoplasmic streaming in slime mold plasmodia. The motive force for protoplasmic streaming is generated by the interaction of actin and myosin. This contraction is supposed to be controlled by intracellular Ca-fluxes similar to the triggering system in skeleton muscle. The histochemical localisation of calcium however is problematic because of the possible diffusion artifacts especially in aquous media.To evaluate this problem calcium localisation was studied in small pieces of shock frozen (liquid propane at -189°C) plasmodial strands of Physarum polycephalum, which were further processed with 3 different methods: 1) freeze substitution in ethanol at -75°C, staining in 100% ethanol with 1% uranyl acetate, and embedding in styrene-methacrylate. For comparison the staining procedure was omitted in some preparations. 2)Freeze drying at about -95°C, followed by immersion with 100% ethanol containing 1% uranyl acetate, and embedding. 3) Freeze fracture, carbon coating and SEM investigation at temperatures below -100° C.

A freeze-fracture-etched study of the physarum polycephalum plasma membrane during early formation of the macroplasmodial stage

1993 ◽  
Vol 51 ◽  
pp. 346-347
Author(s):  
Randolph W. Taylor ◽  
Henrie Treadwell
Keyword(s):  
Plasma Membrane ◽  
Life Cycle ◽  
Growth Phase ◽  
Filter Paper ◽  
Physarum Polycephalum ◽  
Freeze Fracture ◽  
Petri Dish ◽  
Wire Screen ◽  
Wide Mouth ◽  
Sterile Filter

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.

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