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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 -
Zootaxa Sep 2020A survey of myxomycete diversity on five islands of the Seychelles yielded 105 species and 10 infra-specific taxa, which included 89 species on La Digue, 66 on Praslin,...
A survey of myxomycete diversity on five islands of the Seychelles yielded 105 species and 10 infra-specific taxa, which included 89 species on La Digue, 66 on Praslin, 63 on Mahé, 31 on Curieuse and 4 on Félicité. Among these records, 64 species are new for the Seychelles and together with data from the literature, 143 species of myxomycetes are now known for all of the Seychelles. Most collecting on all five islands was carried out in low elevation areas. Forty-four species (73% of all specimens of myxomycetes) were found in low-elevation localities, and among these were Arcyria helvetica, Dictydiaethalium dictyosporum, Echinostelium paucifilum, Physarum aeneum, Ph. echinosporum, Reticularia olivacea, and Stemonaria longa. From 54 species of plants used by myxomycetes as substrates, eight species provided 63% of the specimens of myxomycetes, with most samples recorded from Calophyllum inophyllum. On the basis of substrate type, myxomycetes were distributed as follows: 37% of specimens were collected on dead wood and decaying palm stems, 16% on the bark and stems of living plants, 25% on ground litter, and 22% on aerial litter. A comparison of the assemblages of myxomycetes found in zones with different levels of human impact indicated that 84 species were found in forests, 74 in anthropogenic areas, and 62 in recreational coastal areas. The Seychelles provide a good background for a high level of myxomycete diversity, as a consequence of favorable climatic conditions and their location between Asia and Africa.
Topics: Animals; Biodiversity; Humans; Islands; Myxomycetes; Seychelles
PubMed: 33056725
DOI: 10.11646/zootaxa.4851.2.1 -
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 -
Group I twintrons: genetic elements in myxomycete and schizopyrenid amoeboflagellate ribosomal DNAs.Journal of Biotechnology Sep 1998Protists are unicellular eukaryotes which represent a significant fraction of the global biodiversity. The myxomycete Didymium and the schizopyrenid amoeboflagellate... (Review)
Review
Protists are unicellular eukaryotes which represent a significant fraction of the global biodiversity. The myxomycete Didymium and the schizopyrenid amoeboflagellate Naegleria are distantly related protists. However, we have noted several striking similarities in life cycle, cell morphology, and ribosomal DNA organization between these organisms. Both have multicopy nuclear extrachromosomal ribosomal DNAs. Here the small subunit ribosomal RNA genes are interrupted by an optional group I twintron, a novel category among the group I introns. Group I twintrons are mobile self-splicing introns of 1.3-1.4 kb in size, with a complex organization at the RNA level. A group I twintron consists of two distinct ribozymes (catalytic RNAs) with different functions in RNA processing, and an open reading frame encoding a functional homing endonuclease--all with prospects of application as molecular tools in biotechnology. Updated RNA secondary structure models of group I twintrons, as well as an example of in vitro ribozyme activity, are presented. We suggest that the group I twintrons have been independently established in myxomycetes and schizopyrenid amoeboflagellates by horizontal gene transfer due to a combination of the phagocytotic behavior in natural environments and the extrachromosomal multicopy nature of ribosomal DNA.
Topics: Animals; Base Sequence; DNA, Ribosomal; Eukaryota; Introns; Molecular Sequence Data; Myxomycetes; Nucleic Acid Conformation; RNA; Sequence Homology, Nucleic Acid
PubMed: 9823659
DOI: 10.1016/s0168-1656(98)00104-7 -
Mycologia 2022A new species of the genus (order Physarales, Myxomycetes, Amoebozoa) is described from Peru. Relevant details on spore germination, as well as morphological and...
A new species of the genus (order Physarales, Myxomycetes, Amoebozoa) is described from Peru. Relevant details on spore germination, as well as morphological and phylogenetic data, are provided. At first glance, the new species shares some morphological similarities with both , type of the genus, and , but it strikingly differs from all other species of its genus by combining a short dark stalk, with a reticulate columella, and clustered spores. Moreover, it seems to be the only species of exclusively associated with tropical forests at elevations above 3500 m. Apart from a comprehensive morphological study of 31 specimens, we here provide phylogenetic evidence to confirm the inclusion of this species in the genus . Specifically, our phylogenetic analyses of the nuclear 18S rDNA (18S), mitochondrial 17S rDNA (17S), and elongation factor-1 alpha () genes show that the new species is related to and . The remarkably different morphological characters distinguishing the new from all other species of its genus, along with its particular ecological preferences and geographic distribution, indicate that it is a distinct entity deserving recognition as an independent species.
Topics: DNA, Ribosomal; Forests; Myxomycetes; Peru; Phylogeny
PubMed: 35695815
DOI: 10.1080/00275514.2022.2072140 -
Die Naturwissenschaften Jun 1975The plasmodial stage of Physarum polycephalum contains up to 10(9) nuclei which undergo a naturally synchronous mitosis every 8 h. Nuclear processes such as DNA and RNA... (Review)
Review
The plasmodial stage of Physarum polycephalum contains up to 10(9) nuclei which undergo a naturally synchronous mitosis every 8 h. Nuclear processes such as DNA and RNA synthesis as well as many cytoplasmic processes such as histone synthesis are also synchronous. Physarum polycephalum is therefore widely used in studies of cell-cycle events. This article describes experiments that may help to explain two fundamental biological processes: (1) the mechanism that triggers mitosis, (2) the structural basis of mitotic movement.
Topics: DNA; Histones; Mitosis; Myxomycetes; Physarum; RNA
PubMed: 1105201
DOI: 10.1007/BF00608954 -
Protist Aug 2016Species identification in the myxomycetes (plasmodial slime molds or myxogastrids) poses particular challenges to researchers as a result of their morphological... (Review)
Review
Species identification in the myxomycetes (plasmodial slime molds or myxogastrids) poses particular challenges to researchers as a result of their morphological plasticity and frequent alteration between sexual and asexual life strategies. Traditionally, myxomycete morphology has been used as the primary method of species delimitation. However, with the increasing availability of genetic information, traditional myxomycete taxonomy is being increasingly challenged, and new hypotheses continue to emerge. Due to conflicts that sometimes occur between traditional and more modern species concepts that are based largely on molecular data, there is a pressing need to revisit the discussion surrounding the species concept used for myxomycetes. Biological diversity is being increasingly studied with molecular methods and data accumulates at ever-faster rates, making resolution of this matter urgent. In this review, currently used and potentially useful species concepts (biological, morphological, phylogenetic and ecological) are reviewed, and an integrated approach to resolve the myxomycete species problem is discussed.
Topics: Biodiversity; Classification; Myxomycetes
PubMed: 27351595
DOI: 10.1016/j.protis.2016.05.003 -
Journal of Natural Products Mar 2023The myxomycete , colloquially referred to as "dog vomit fungus", forms vibrant yellow fruiting bodies (aethalia) on wood chips during warm and humid conditions in...
The myxomycete , colloquially referred to as "dog vomit fungus", forms vibrant yellow fruiting bodies (aethalia) on wood chips during warm and humid conditions in spring. In 2018, ideal climatic conditions in Sydney, Australia, provided a rare opportunity to access abundant quantities of aethalia, which enabled the isolation, purification, structure elucidation, and biological screening of two avenalumamide pyrones, fuligopyrone () and fuligopyrone B (). While and did not exhibit any appreciable biological activity, their significant UV absorption at 325 nm suggested they may be acting as transient sunscreens to help protect the fruiting mass from exposure to sunlight. In support of this hypothesis, exposing a solution of to direct sunlight for 5 min resulted in rapid equilibration with a mixture of 2,4-fuligopyrone B () and 2,4-fuligopyrone B () photoisomers.
Topics: Animals; Dogs; Myxomycetes; Ultraviolet Rays; Ascomycota; Fruiting Bodies, Fungal; Australia
PubMed: 36655352
DOI: 10.1021/acs.jnatprod.2c00989 -
Mycologia 2021A new nivicolous myxomycete is described as a result of a comprehensive study of collections from the entire range of its occurrence. Statistical analysis of 12...
A new nivicolous myxomycete is described as a result of a comprehensive study of collections from the entire range of its occurrence. Statistical analysis of 12 morphological characters, phylogenetic analyses of nuc 18S rDNA and elongation factor 1-alpha gene (), and a delimitation method (automatic barcode gap diversity) have been applied to corroborate the identity of the new species. A preliminary morphological analysis of revealed high variability of South American populations where four types of spore ornamentation were noted. However, results of molecular study and statistical analysis of morphological characters did not support recognition of these four forms but the distinction of two morphotypes. Consequently, two species have been recognized: and the newly proposed . The new species can be distinguished from by distinctly larger and mostly plasmodiocarpic sporophores, which are scattered to gregarious, paler spores, and by the paler, more delicate and more elastic capillitium. Spore ornamentation of is uniform and can be described as distinctly spiny (pilate under scanning electron microscope [SEM]), whereas those of is more variable, where spines (pilae under SEM) are delicate, distinct, or conspicuous. Additionally, whereas is a species distributed worldwide, occurs only in the austral Andes of Argentina and Chile.
Topics: Argentina; DNA, Ribosomal; Myxomycetes; Phylogeny; Physarida
PubMed: 34533412
DOI: 10.1080/00275514.2021.1961068 -
Morphological stasis in the first myxomycete from the Mesozoic, and the likely role of cryptobiosis.Scientific Reports Dec 2019Myxomycetes constitute a group within the Amoebozoa well known for their motile plasmodia and morphologically complex fruiting bodies. One obstacle hindering studies of...
Myxomycetes constitute a group within the Amoebozoa well known for their motile plasmodia and morphologically complex fruiting bodies. One obstacle hindering studies of myxomycete evolution is that their fossils are exceedingly rare, so evolutionary analyses of this supposedly ancient lineage of amoebozoans are restricted to extant taxa. Molecular data have significantly advanced myxomycete systematics, but the evolutionary history of individual lineages and their ecological adaptations remain unknown. Here, we report exquisitely preserved myxomycete sporocarps in amber from Myanmar, ca. 100 million years old, one of the few fossil myxomycetes, and the only definitive Mesozoic one. Six densely-arranged stalked sporocarps were engulfed in tree resin while young, with almost the entire spore mass still inside the sporotheca. All morphological features are indistinguishable from those of the modern, cosmopolitan genus Stemonitis, demonstrating that sporocarp morphology has been static since at least the mid-Cretaceous. The ability of myxomycetes to develop into dormant stages, which can last years, may account for the phenotypic stasis between living Stemonitis species and this fossil one, similar to the situation found in other organisms that have cryptobiosis. We also interpret Stemonitis morphological stasis as evidence of strong environmental selection favouring the maintenance of adaptations that promote wind dispersal.
Topics: Biological Evolution; Fossils; Myxomycetes; Phylogeny
PubMed: 31874965
DOI: 10.1038/s41598-019-55622-9