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Mycologia 2015A new species of myxomycete, Perichaena longipes, is described from 56 sporocarp specimens that appeared in moist chamber cultures prepared with samples of decaying...
A new species of myxomycete, Perichaena longipes, is described from 56 sporocarp specimens that appeared in moist chamber cultures prepared with samples of decaying plant materials collected in Panama, Costa Rica and Brazil. This new species is distinguished from the morphologically similar species P. pedata on the basis of the much longer stipe, lighter peridium and the unique ornamentation of the capillitium. The nuc 18S ribosomal DNA sequences obtained from four specimens of P. longipes support the distinction of this new taxon and its separation from P. pedata. Furthermore, maximum likelihood phylogeny supports earlier evidence that species currently within the genus Perichaena do not form a monophyletic clade. Instead they appear to form three separate branches within the bright-spored clade. The first clade includes P. longipes together with several species of Trichia and Metatrichia, the second includes P. pedata and P. chrysosperma, and the third clade is composed of P. corticalis, P. depressa and P. luteola.
Topics: DNA, Fungal; Microscopy, Electron, Scanning; Myxomycetes; Panama; RNA, Fungal; RNA, Ribosomal, 18S; Species Specificity
PubMed: 26240305
DOI: 10.3852/14-330 -
Mycologia 2015A new species of Didymium (Myxomycetes), D. xerophilum, is described, and some details of its life cycle are provided. The new species was collected during studies of...
A new species of Didymium (Myxomycetes), D. xerophilum, is described, and some details of its life cycle are provided. The new species was collected during studies of arid areas of Argentina and Peru. It can be distinguished by the persistent funnel-shaped invagination of the peridium, the top of which appears as a deep umbilicus in closed sporothecae, and the calcareous hypothallus shared among several sporocarps. This combination of characters, with a circumscissile dehiscence of the sporotheca and a cream stalk packed with rhombic lime crystals, is unknown in other described species. Morphology was examined with scanning electron microscopy and light microscopy, and micrographs of relevant details are included here. Phylogenetic analysis with 18S rDNA sequences of different species of Didymium supports the distinct identity of this new species. Some collections of this myxomycete were made at up to 4600 m, an altitude almost unknown for this group of microorganisms.
Topics: Altitude; Argentina; Molecular Sequence Data; Myxomycetes; Peru; Phylogeny; Spores, Protozoan
PubMed: 25232071
DOI: 10.3852/14-058 -
Developmental Genetics 1988The formation of secondary sori in whorls of Polysphondylium pallidum provides an attractive model system for the study of symmetry breaking during morphogenesis.... (Review)
Review
The formation of secondary sori in whorls of Polysphondylium pallidum provides an attractive model system for the study of symmetry breaking during morphogenesis. Tip-specific antibodies that permit detection of very early stages in this patterning process are available. We have found that the patterns of tip-specific antigen expression vary considerably depending on the size, shape, and developmental stage of the whorl. All of these patterns, however, are well explained by patterning models that rely on short-range autocatalysis and long-range inhibition, as exemplified by reaction-diffusion theories. In the context of reaction-diffusion, we discuss the possible effects of initial conditions, boundary conditions, and nonlinearities on the selection of patterns in P. pallidum whorls.
Topics: Models, Theoretical; Morphogenesis; Myxomycetes
PubMed: 3072135
DOI: 10.1002/dvg.1020090442 -
Journal of Cellular and Comparative... Aug 1952
Topics: Actin Cytoskeleton; Actomyosin; Myxomycetes; Plasmodium
PubMed: 12981137
DOI: 10.1002/jcp.1030400109 -
Bio Systems Feb 2016Left-right patterning and lateralised behaviour is an ubiquitous aspect of plants and animals. The mechanisms linking cellular chirality to the large-scale asymmetry of...
Left-right patterning and lateralised behaviour is an ubiquitous aspect of plants and animals. The mechanisms linking cellular chirality to the large-scale asymmetry of multicellular structures are incompletely understood, and it has been suggested that the chirality of living cells is hardwired in their cytoskeleton. We examined the question of biased asymmetry in a unique organism: the slime mould Physarum polycephalum, which is unicellular yet possesses macroscopic, complex structure and behaviour. In laboratory experiment using a T-shape, we found that Physarum turns right in more than 74% of trials. The results are in agreement with previously published studies on asymmetric movement of muscle cells, neutrophils, liver cells and growing neural filaments, and for the first time reveal the presence of consistently-biased laterality in the fungi kingdom. Exact mechanisms of the slime mould's direction preference remain unknown.
Topics: Body Patterning; Cell Movement; Computer Simulation; Models, Biological; Models, Statistical; Myxomycetes; Physarum polycephalum
PubMed: 26747637
DOI: 10.1016/j.biosystems.2015.12.008 -
Protist Aug 2018Myxomycetes is one of the largest groups of protists belonging to Amoebozoa, with ca 1,000 species recognised and more than 4,000 names in use. Historically, myxomycetes... (Review)
Review
Myxomycetes is one of the largest groups of protists belonging to Amoebozoa, with ca 1,000 species recognised and more than 4,000 names in use. Historically, myxomycetes were considered fungi or protozoans which, however, fell under the provisions of the former International Code of Botanical Nomenclature (ICBN), currently the International Code of Nomenclature for algae, fungi, and plants (ICN). Attempts to apply the International Code of Zoological Nomenclature (ICZN) to myxomycetes were rare and inconsistent; thus, we argue that Myxomycetes is not a truly ambiregnal group (i.e. one falling under both Codes). Recently, nomenclatural novelties within Myxomycetes have been proposed using ICZN rules, and the application of zoological orthography to myxomycete higher-level taxa in the recent amoebozoan phylogenies is increasingly common. We summarise the consequences of application of either ICN or ICZN to Myxomycetes. In our opinion, nomenclatural stability within Myxomycetes is best served by strict application of ICN. Either treating myxomycetes as falling under ICZN or considering them an ambiregnal group would cause serious nomenclatural instability, mainly owing to the incompatibility of the two Codes as to the date of the starting point of nomenclature and to the appearance of numerous homonyms.
Topics: Myxomycetes; Phylogeny; Terminology as Topic
PubMed: 29936290
DOI: 10.1016/j.protis.2018.05.002 -
Journal of Bacteriology Aug 1963Daniel, John W. (University of Wisconsin, Madison), Karlee L. Babcock, Alice H. Sievert, and Harold P. Rusch. Organic requirements and synthetic media for growth of the...
Daniel, John W. (University of Wisconsin, Madison), Karlee L. Babcock, Alice H. Sievert, and Harold P. Rusch. Organic requirements and synthetic media for growth of the myxomycete Physarum polycephalum. J. Bacteriol. 86:324-331. 1963.-An isolate of Physarum polycephalum was maintained in submersed pure culture in a completely defined medium, giving cell yields approximately 70% of those obtained in a partially defined medium. Optimal concentrations of the absolute organic requirements, identified as d- or l-methionine, biotin, thiamine, and hematin as previously reported, were established. Glycine was highly stimulatory. In a minimal medium, alanine or glutamine, not required in the complete medium, stimulated growth and appeared to function as sources for transamination. Arginine was also required in the minimal medium. The cell yield in a simplified medium containing the absolute requirements plus glycine, alanine, and arginine was approximately the same as that in the complete medium, but the growth rate was about 25% lower.
Topics: Biotin; Culture Media; Glycine; Heme; Methionine; Myxomycetes; Physarum polycephalum; Research; Thiamine
PubMed: 14058960
DOI: 10.1128/jb.86.2.324-331.1963 -
Journal of Bacteriology Mar 1969A method has been developed for growing Physarum polycephalum plasmodia that are 8 to 10 times larger than those obtained in the petri dish cultures used by Nygaard,...
A method has been developed for growing Physarum polycephalum plasmodia that are 8 to 10 times larger than those obtained in the petri dish cultures used by Nygaard, Guttes, and Rusch. In the large-scale procedure, plasmodia were grown in metal trays on a membrane supported by filter paper on stainless-steel screen. Plasmodia were started from a ring of inoculum to allow inward and outward migration and were incubated on a rocker so that nutrient medium would flow back and forth, wetting the undersurface of the plasmodium. Rocker and petri dish cultures had similar growth characteristics: (i) the interphase time between mitoses I and II and between II and III was about 8 hr; (ii) ribonucleic acid and protein increased essentially logarithmically throughout the cell cycle; and (iii) deoxyribonucleic acid increased only during early interphase and it doubled in approximately 3 hr after each mitosis. Rocker cultures were not as nearly synchronous as petri dish cultures and had a range in metaphase time (at mitosis III) within individual plasmodia of 15 to 45 min, as compared with 5 to 10 min in petri dish cultures.
Topics: DNA; Methods; Microbiology; Mitosis; Myxomycetes; Proteins; RNA
PubMed: 5813343
DOI: 10.1128/jb.97.3.1411-1418.1969 -
Mycologia 2013A new nivicolous species of Physarum was discovered during the study of myxomycetes in the Patagonian Andes of South America. It is described herein under the name...
A new nivicolous species of Physarum was discovered during the study of myxomycetes in the Patagonian Andes of South America. It is described herein under the name Physarum andinum. The species is characterized by stalked sporophores or more rarely sessile sporocarps or short plasmodiocarps. The sporocarps are strikingly large, reaching 2.6 mm tall and 3 mm diam when open, and have a peridium with three layers, the internal layer being clearly visible and opening separately. Physarum andinum was found at five localities in Argentina as well as in herbarium material collected about 100 y ago in Chile. The new species is reminiscent of the non-nivicolous species Physarum brunneolum, but the latter forms smaller sporophores, has darker spores and the three layers of the peridium are adhered and open together. The characters of the new species were examined under stereomicroscope, light microscope and scanning electron microscope and micrographs of relevant details are included.
Topics: Argentina; Chile; Physarum; Soil; Spores, Protozoan; Trees
PubMed: 22962350
DOI: 10.3852/11-397 -
The Journal of General Physiology May 19561. A procedure has been developed for the preparation of an active concentrate from the myxomycete, Physarum polycephalum. This concentrate responds with a lowered...
1. A procedure has been developed for the preparation of an active concentrate from the myxomycete, Physarum polycephalum. This concentrate responds with a lowered viscosity to the addition of small amounts of ATP. The preparation recovers in viscosity, and the process may be repeated. 2. In the most active concentrates, 75 per cent of the non-dialyzable material moves as a single boundary both in the descending limb in electrophoresis and in the ultracentrifuge. It contains about 10 per cent ribonucleic acid, which is at least in part reversibly bound to the protein. 3. The active material has been designated myxomyosin because of its origin and its similarity to actomyosin in ATP response.
Topics: Actomyosin; Adenosine Triphosphate; Bacteria; Myxomycetes; Physarum; Plasmodium; Proteins
PubMed: 13319663
DOI: 10.1085/jgp.39.5.801