New Mating Types in Physarum polycephalum

Mycologia ◽  
1977 ◽  
Vol 69 (2) ◽  
pp. 421 ◽  
Author(s):  
O'Neil Ray Collins ◽  
Hsi-Chang Tang
Keyword(s):  
Physarum Polycephalum ◽  
Mating Types

scholarly journals Selfing mutants from heterothallic strains of Physarum polycephalum

1981 ◽  
Vol 37 (2) ◽  
pp. 113-121 ◽  
Author(s):  
N. K. Honey ◽  
R. T. M. Poulter ◽  
P. J. Winter
Keyword(s):  
Temperature Effect ◽  
Mating Type ◽  
Physarum Polycephalum ◽  
Single Locus ◽  
Mating Types ◽  
Specific Sensitivity

SUMMARYPlasmodial formation in the myxomycete Physarum polycephalum is controlled by a mating type (mt) locus, with heterothallic amoebae normally being unable to form plasmodia in pure clones. We report the isolation by mutagenesis of selfing mutants from heterothallic strains, and their analysis. Various amoebal strains of different mating types were mutagenized with a range of mutagens, and a number of selfing mutants (designated Het−) were isolated. A specific sensitivity of mt2 amoebae to mutagenesis by NMG was observed. This sensitivity segregated as a single locus closely linked or allelic to the mt2 locus. When the Het− clones were incubated at 30 °C, selfing was greatly inhibited. This property was used to determine the mt specificities of four Het− clones. The process of plasmodial induction in pure clones of CL was also studied using the 30 °C temperature effect.

Mating Types in Five Isolates of Physarum polycephalum

Mycologia ◽  
1975 ◽  
Vol 67 (1) ◽  
pp. 98 ◽  
Author(s):  
O'Neil Ray Collins
Keyword(s):  
Physarum Polycephalum ◽  
Mating Types

Mating Types in Five Isolates of Physarum Polycephalum

Mycologia ◽  
1975 ◽  
Vol 67 (1) ◽  
pp. 98-107 ◽  
Author(s):  
O'Neil Ray Collins
Keyword(s):  
Physarum Polycephalum ◽  
Mating Types

scholarly journals Rapid, Selective Digestion of Mitochondrial DNA in Accordance With the matA Hierarchy of Multiallelic Mating Types in the Mitochondrial Inheritance of Physarum polycephalum

Genetics ◽  
2003 ◽  
Vol 164 (3) ◽  
pp. 963-975 ◽  
Author(s):  
Y Moriyama ◽  
S Kawano
Keyword(s):  
Mitochondrial Dna ◽  
Physarum Polycephalum ◽  
Nuclear Fusion ◽  
The Other ◽  
Pcr Analysis ◽  
Uniparental Inheritance ◽  
Mating Types ◽  
Mitochondrial Inheritance ◽  
Biparental Inheritance ◽  
Mitochondrial Nucleoids

Abstract Although mitochondria are inherited uniparentally in nearly all eukaryotes, the mechanism for this is unclear. When zygotes of the isogamous protist Physarum polycephalum were stained with DAPI, the fluorescence of mtDNA in half of the mitochondria decreased simultaneously to give small spots and then disappeared completely ∼1.5 hr after nuclear fusion, while the other mitochondrial nucleoids and all of the mitochondrial sheaths remained unchanged. PCR analysis of single zygote cells confirmed that the loss was limited to mtDNA from one parent. The vacant mitochondrial sheaths were gradually eliminated by 60 hr after mating. Using six mating types, the transmission patterns of mtDNA were examined in all possible crosses. In 39 of 60 crosses, strict uniparental inheritance was confirmed in accordance with a hierarchy of relative sexuality. In the other crosses, however, mtDNA from both parents was transmitted to plasmodia. The ratio of parental mtDNA was estimated to be from 1:1 to 1:10-4. Nevertheless, the matA hierarchy was followed. In these crosses, the mtDNA was incompletely digested, and mtDNA replicated during subsequent plasmodial development. We conclude that the rapid, selective digestion of mtDNA promotes the uniparental inheritance of mitochondria; when this fails, biparental inheritance occurs.

New Mating Types in Physarum Polycephalum

Mycologia ◽  
1977 ◽  
Vol 69 (2) ◽  
pp. 421-423 ◽  
Author(s):  
O'Neil Ray Collins ◽  
Hsi-Chang Tang
Keyword(s):  
Physarum Polycephalum ◽  
Mating Types

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.

Characterization of a Motile Cellular Domain Arising During the Amoebo-Flagellate Transformation of Physarum Polycephalum

1980 ◽  
Vol 38 ◽  
pp. 552-553
Author(s):  
K.I. Pagh ◽  
M.R. Adelman
Keyword(s):  
Cell Shape ◽  
Physarum Polycephalum ◽  
Slime Mold ◽  
Live Cells ◽  
Cellular Domain

Unicellular amoebae of the slime mold Physarum polycephalum undergo marked changes in cell shape and motility during their conversion into flagellate swimming cells (l). To understand the processes underlying motile activities expressed during the amoebo-flagellate transformation, we have undertaken detailed investigations of the organization, formation and functions of subcellular structures or domains of the cell which are hypothesized to play a role in movement. One focus of our studies is on a structure, termed the “ridge” which appears as a flattened extension of the periphery along the length of transforming cells (Fig. 1). Observations of live cells using Nomarski optics reveal two types of movement in this region:propagation of undulations along the length of the ridge and formation and retraction of filopodial projections from its edge. The differing activities appear to be associated with two characteristic morphologies, illustrated in Fig. 1.

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