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Microorganisms Sep 2023Evidence from molecular studies indicates that myxomycetes (also called myxogastrids or plasmodial slime molds) have a long evolutionary history, and the oldest known... (Review)
Review
Evidence from molecular studies indicates that myxomycetes (also called myxogastrids or plasmodial slime molds) have a long evolutionary history, and the oldest known fossil is from the mid-Cretaceous. However, they were not "discovered" until 1654, when a brief description and a woodcut depicting what is almost certainly the common species was published. First thought to be fungi, myxomycetes were not universally recognized as completely distinct until well into the twentieth century. Biodiversity surveys for the group being carried out over several years are relatively recent, with what is apparently the first example being carried out in the 1930s. Beginning in the 1980s, a series of such surveys yielded large bodies of data on the occurrence and distribution of myxomycetes in terrestrial ecosystems. The most notable of these were the All Taxa Biodiversity Inventory (ATBI) project carried out in the Great Smoky Mountains National Park, the Planetary Biodiversity Inventory Project (PBI) carried out in localities throughout the world, and the Myxotropic project being carried out throughout the Neotropics. The datasets available from both past and ongoing surveys now allow global and biogeographical patterns of myxomycetes to be assessed for the first time.
PubMed: 37764126
DOI: 10.3390/microorganisms11092283 -
Mycologia 2024A new myxomycete species, , was reported herein. The specimens were found and collected in the field on dead bark from Jingangtai National Geopark in Henan Province of...
A new myxomycete species, , was reported herein. The specimens were found and collected in the field on dead bark from Jingangtai National Geopark in Henan Province of China. This species has distinct and unique morphological characteristics, including dark grayish olive sporothecae that fade to smoke gray with age, shallow saucer-shaped cups with marked reticulations and thick papillae on the inner surface, a netted capillitium with many bulges, uniformly marked with low, dense, and irregular reticulations, and spores (8.0-)9.3-10.1(-10.9) μm in diameter, marked with sparse small warts and grouped prominent warts. Apart from a comprehensive morphological study, partial sequences of the nuclear 18S rDNA and elongation factor-1 alpha () genes were also provided in this study. This new species was described and illustrated morphologically. The specimens are deposited in the Herbarium of Fungi of Nanjing Normal University (HFNNU).
Topics: China; Phylogeny; Myxomycetes; RNA, Ribosomal, 18S; Peptide Elongation Factor 1; DNA, Ribosomal; Plant Bark; Sequence Analysis, DNA; Molecular Sequence Data
PubMed: 38442243
DOI: 10.1080/00275514.2024.2312077 -
Mycology 2023Species in the class Myxomycetes (or Myxogastrea) are essential components of biodiversity and play important ecological roles in terrestrial ecosystems, especially in... (Review)
Review
Species in the class Myxomycetes (or Myxogastrea) are essential components of biodiversity and play important ecological roles in terrestrial ecosystems, especially in forests. Studies on the taxonomy and diversity of these organisms started late in China. However, significant progress in China has been made in modern taxonomic studies on myxomycetes based on long-term species surveying and specimen collecting. The existing achievements have shown that comprehensive and continuous studies on the taxonomy and diversity of myxomycetes in China have the potential to enhance global biodiversity and improve the geographic distribution pattern of myxomycetes. Therefore, building on the current research foundation and expanding myxomycete research in a wider and more in-depth approach is imperative.
PubMed: 38187883
DOI: 10.1080/21501203.2023.2255031 -
European Journal of Protistology Aug 2023More than 1272 myxomycetes species have been described, accounting for more than half of all Amoebozoa species. However, the genome size of only three myxomycetes...
More than 1272 myxomycetes species have been described, accounting for more than half of all Amoebozoa species. However, the genome size of only three myxomycetes species has been reported. Therefore, we used flow cytometry to present an extensive survey and a phylogeny-based analysis of genome size and GC content evolution in 144 myxomycetes species. The genome size of myxomycetes ranged from 18.7 Mb to 470.3 Mb, and the GC content ranged from 38.7% to 70.1%. Bright-spored clade showed larger genome sizes and more intra-order genome size variations than the dark-spored clade. GC content and genome size were positively correlated in both bright-spored and dark-spored clades, and spore size was positively correlated with genome size and GC content in the bright-spored clade. We provided the first genome size data set in Myxomycetes, and our results will provide helpful information for future Myxomycetes studies, such as genome sequencing.
Topics: Genome Size; Myxomycetes; Base Composition; Phylogeny; Amoebozoa
PubMed: 37331249
DOI: 10.1016/j.ejop.2023.125991 -
Mycologia 2023Based on a study of 255 collections from four continents and four floristic kingdoms, we describe 15 new species of the genus . The new species, all morphologically...
Based on a study of 255 collections from four continents and four floristic kingdoms, we describe 15 new species of the genus . The new species, all morphologically close to , and , differ from each other by the structure of the peridium and, in some cases, also by the color of the fresh spore mass and the ornamentation of the capillitium and spores. Species delimitation is confirmed by two independently inherited molecular markers, as well as previously performed tests of reproductive isolation and genetic distances. We studied authentic material of and and found fresh specimens of these species, which allowed us to obtain molecular barcodes and substantiate the separation of new species from these taxa. We propose to retain the name for the globally most abundant species, for which we provide a more precise description and a neotypification. Two formerly described species, and , we consider to be dubious. We do not recognize the species .
Topics: Microscopy, Electron, Scanning; Myxomycetes; Spores, Protozoan; Species Specificity; DNA, Protozoan; DNA Barcoding, Taxonomic
PubMed: 37224183
DOI: 10.1080/00275514.2023.2199109 -
Physical Biology Nov 2023The tubular network-forming slime moldis able to maintain long-scale contraction patterns driven by an actomyosin cortex. The resulting shuttle streaming in the network...
The tubular network-forming slime moldis able to maintain long-scale contraction patterns driven by an actomyosin cortex. The resulting shuttle streaming in the network is crucial for the organism to respond to external stimuli and reorganize its body mass giving rise to complex behaviors. However, the chemical basis of the self-organized flow pattern is not fully understood. Here, we present ratiometric measurements of free intracellular calcium in simple morphologies ofnetworks. The spatiotemporal patterns of the free calcium concentration reveal a nearly anti-correlated relation to the tube radius, suggesting that calcium is indeed a key regulator of the actomyosin activity. We compare the experimentally observed phase relation between the radius and the calcium concentration to the predictions of a theoretical model including calcium as an inhibitor. Numerical simulations of the model suggest that calcium indeed inhibits the contractions in, although a quantitative difference to the experimentally measured phase relation remains. Unraveling the mechanism underlying the contraction patterns is a key step in gaining further insight into the principles of's complex behavior.
Topics: Calcium; Actomyosin; Models, Theoretical; Actin Cytoskeleton; Physarum polycephalum
PubMed: 37975194
DOI: 10.1088/1478-3975/ad0a9a -
Animal Cognition Nov 2023Sensing, communication, navigation, decision-making, memory and learning are key components in a standard cognitive tool-kit that enhance an animal's ability to... (Review)
Review
Sensing, communication, navigation, decision-making, memory and learning are key components in a standard cognitive tool-kit that enhance an animal's ability to successfully survive and reproduce. However, these tools are not only useful for, or accessible to, animals-they evolved long ago in simpler organisms using mechanisms which may be either unique or widely conserved across diverse taxa. In this article, I review the recent research that demonstrates these key cognitive abilities in the plasmodial slime mould Physarum polycephalum, which has emerged as a model for non-animal cognition. I discuss the benefits and limitations of comparisons drawn between neural and non-neural systems, and the implications of common mechanisms across wide taxonomic divisions. I conclude by discussing future avenues of research that will draw the most benefit from a closer integration of Physarum and animal cognition research.
Topics: Animals; Physarum polycephalum; Cognition; Learning
PubMed: 37166523
DOI: 10.1007/s10071-023-01782-1 -
Mycologia 2024A new genus and species of myxomycete, , is described based on numerous observations in Tasmania and additional records from southeastern Australia and New Zealand. The...
A new genus and species of myxomycete, , is described based on numerous observations in Tasmania and additional records from southeastern Australia and New Zealand. The new taxon is characterized by an unusual combination of characters from two families: Lamprodermataceae and Didymiaceae. With Lamprodermataceae the species shares limeless sporocarps, a shining membranous peridium, an epihypothallic stalk, and a cylindrical columella. Like Didymiaceae, it has a soft, flaccid, sparsely branched capillitium, with rough tubular threads that contain fusiform nodes and are firmly connected to the peridium. Other characters of that also occur in many Didymiaceae are the peridium dehiscing into petaloid lobes, the yellow, motile plasmodium, and the spores ornamented with larger, grouped and smaller, scattered warts. The transitional position of the new taxon is reflected by a three-gene phylogeny, which places at the base of the branch of all lime-containing Physarales, thus justifying its description as a monotypic genus.
Topics: Humans; Myxomycetes; Tasmania; Physarida; Spores, Protozoan; Australia; Phylogeny
PubMed: 38032605
DOI: 10.1080/00275514.2023.2274252 -
Biochemical and Biophysical Research... Nov 2023Desiccation is a severe survival problem for organisms. We have been studying the desiccation tolerance mechanisms in the true slime mold Physarum polycephalum. We...
Desiccation is a severe survival problem for organisms. We have been studying the desiccation tolerance mechanisms in the true slime mold Physarum polycephalum. We measured the trehalose content of P. polycephalum vegetative cells (plasmodia) and drought cells (sclerotia). Surprisingly, we found that the content in sclerotia was about 473-fold greater than in the plasmodia. We then examined trehalose metabolism-related genes via RNAseq, and consequently found that trehalose 6-phosphate phosphorylase (T6pp) expression levels increased following desiccation. Next, we cloned and expressed the genes for T6pp, trehalose 6-phosphate synthase/phosphatase (Tps/Tpp), maltooligosyltrehalose trehalohydrolase (TreZ), and maltooligosyltrehalose synthase (TreY) in E. coli. Incidentally, TreY and TreZ clones have been reported in several prokaryotes, but not in eukaryotes. This report in P. polycephalum is the first evidence of their presence in a eukaryote species. Recombinant T6pp, TreY, and TreZ were purified and confirmed to be active. Our results showed that these enzymes catalyze reactions related to trehalose production, and their reaction kinetics follow the Michaelis-Menten equation. The t6pp mRNA levels of the sclerotia were about 15-fold higher than in the plasmodia. In contrast, the expression levels of TreZ and TreY showed no significant change between the sclerotia and plasmodia. Thus, T6pp is probably related to desiccation tolerance, whereas the contribution of TreY and TreZ is insufficient to account for the considerable accumulation of trehalose in sclerotia.
Topics: Trehalose; Escherichia coli; Physarum; Biosynthetic Pathways; Phosphates
PubMed: 37832387
DOI: 10.1016/j.bbrc.2023.09.090 -
Frontiers in Plant Science 2024Myxomycetes (plasmodial slime molds) are eukaryotic protist predators that are associated with wood, leaf litter, and soil in forests, where they feed on bacteria,... (Review)
Review
Myxomycetes (plasmodial slime molds) are eukaryotic protist predators that are associated with wood, leaf litter, and soil in forests, where they feed on bacteria, protozoans, and (to a more limited extent) fungi. The health of crop plants is essential because they represent a primary food source for humans. However, when myxomycetes produce numerous fruiting bodies on the stems and leaves of crop plants, which is herein referred to as a myxomycete colonization, this has the potential of interfering with plant photosynthesis, transpiration and respiration by blocking out light and covering stomata. Myxomycetes are not pathogens, but their occurrence on plants can be mistakenly interpreted as some type of infection. However, this phenomenon has been largely ignored. This paper provides a comprehensive overview of the taxonomic and economic diversity of the organisms involved in myxomycete colonization. In addition, the various types of myxomycete colonization reported in the literature are described and discussed, a number of images provided, and cultural and chemical prevention and control measures are summarized. The latter should be of significant relevance for local production of crops and plant protective stations. While myxomycetes are not pathogens of crop plants, some species can seriously impact commercially grown mushrooms. Reports of myxomycetes affecting mushrooms are also described in this paper.
PubMed: 38916031
DOI: 10.3389/fpls.2024.1411231