RESUMEN
Four species of myxomycetes (Arcyria pseudodenudata, Diderma europaeum, Lycogala irregulare, and Trichia armillata) new to China were observed via light microscope and scanning electron microscope, and detailed descriptions and illustrations are provided, along with comparisons with related species. Among them, A. pseudodenudata was discovered for the first time outside of the type locality, D. europaeum was discovered for the first time outside of Europe, and L. irregulare and T. armillata were reported again after being named. Phylogenetic analyses based on nuclear 18S rDNA and elongation factor-1 alpha sequences or nuclear 18S rDNA and cytochrome oxidase subunit I sequences was performed to provide a molecular basis for morphological identification. These specimens were deposited in the Herbarium of Fungi of Nanjing Normal University.
Asunto(s)
Mixomicetos , Filogenia , ARN Ribosómico 18S , China , Mixomicetos/clasificación , Mixomicetos/genética , Mixomicetos/aislamiento & purificación , Mixomicetos/ultraestructura , ARN Ribosómico 18S/genética , ADN Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Factor 1 de Elongación Peptídica/genética , Análisis de Secuencia de ADNRESUMEN
Myxomycetes are multinucleate unicellular organisms. They form a Plasmodium that moves by protoplasmic flow and prey on microorganisms. When encountering intraspecifics, the plasmodium has the capacity for 'fusion', actively approaching and fusing its cells, or 'avoidance', altering its direction to avoid the other individual. This is an allorecognition ability. However, it remains unclear whether the range of allorecognition extends to other species, and its ecological significance is also obscure. Here, we conducted a quantitative evaluation of contact responses from closely related species of plasmodium to clarify the range of allorecognition behaviors in Myxomycetes. Behavioral assays demonstrated that allorecognition behaviors are specifically observed within individuals of the same species, indicating that these behaviors are a phenomenon unique to intraspecies interactions. Myxomycetes allorecognition is an extremely narrow and inward-focused behavior, suggesting a highly specialized mechanism.
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Mixomicetos , Mixomicetos/fisiología , Plasmodium/fisiología , Especificidad de la Especie , AnimalesRESUMEN
A new myxomycete species, Arcyria similaris, 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 (EF-1α) 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).
Asunto(s)
ADN Ribosómico , Mixomicetos , Factor 1 de Elongación Peptídica , Filogenia , ARN Ribosómico 18S , China , Mixomicetos/clasificación , Mixomicetos/genética , Mixomicetos/aislamiento & purificación , ARN Ribosómico 18S/genética , Factor 1 de Elongación Peptídica/genética , ADN Ribosómico/genética , Corteza de la Planta/microbiología , Corteza de la Planta/parasitología , Análisis de Secuencia de ADN , Datos de Secuencia MolecularRESUMEN
The family Physaraceae (Physarales, Myxomycetes) is represented in Brazil by eight genera and 75 species. Based on data obtained from the GBIF, SpeciesLink, Flora and Funga do Brasil platforms, collections from the IPA and URM Herbaria and material collected since 1960 deposited in the UFP Herbarium, the microhabitats and distribution of Badhamiopsis (1sp.) and Badhamia (10 spp.) in Brazilian biomes are commented. An identification key for the species and the first report of B. melanospora from the state of Paraíba, B. panicea from the state of Paraná and B. ovispora from Brazil are presented.
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Mixomicetos , Brasil , EcosistemaRESUMEN
Brilliant colors in nature arise from the interference of light with periodic nanostructures resulting in structural color. While such biological photonic structures have long attracted interest in insects and plants, they are little known in other groups of organisms. Unexpected in the kingdom of Amoebozoa, which assembles unicellular organisms, structural colors were observed in myxomycetes, an evolutionary group of amoebae forming macroscopic, fungal-like structures. Previous work related the sparkling appearance of Diachea leucopodia to thin film interference. Using optical and ultrastructural characterization, we here investigated the occurrence of structural color across 22 species representing two major evolutionary clades of myxomycetes including 14 genera. All investigated species showed thin film interference at the peridium, producing colors with hues distributed throughout the visible range that were altered by pigmentary absorption. A white reflective layer of densely packed calcium-rich shells is observed in a compound peridium in Metatrichia vesparium, whose formation and function are still unknown. These results raise interesting questions on the biological relevance of thin film structural colors in myxomycetes, suggesting they may be a by-product of their reproductive cycle.
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Amebozoos , Mixomicetos , Nanoestructuras , Calcio , FotonesRESUMEN
The nivicolous species of the genus Diderma are challenging to identify, and there are several competing views on their delimitation. We analyzed 102 accessions of nivicolous Diderma spp. that were sequenced for two or three unlinked genes to determine which of the current taxonomic treatments is better supported by molecular species delimitation methods. The results of a haplotype web analysis, Bayesian species delimitation under a multispecies coalescent model, and phylogenetic analyses on concatenated alignments support a splitting approach that distinguishes six taxa: Diderma alpinum, D. europaeum, D. kamchaticum, D. meyerae, D. microcarpum and D. niveum. The first two approaches also support the separation of Diderma alpinum into two species with allopatric distribution. An extended dataset of 800 specimens (mainly from Europe) that were barcoded with 18S rDNA revealed only barcode variants similar to those in the species characterized by the first data set, and showed an uneven distribution of these species in the Northern Hemisphere: Diderma microcarpum and D. alpinum were the only species found in all seven intensively sampled mountain regions. Partial 18S rDNA sequences serving as DNA barcodes provided clear signatures that allowed for unambiguous identification of the nivicolous Diderma spp., including two putative species in D. alpinum.
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Mixomicetos , Código de Barras del ADN Taxonómico/métodos , Teorema de Bayes , Filogenia , ADN Ribosómico/genéticaRESUMEN
Three Parallel Rivers is one of the world's biodiversity hotspots. However, the research on myxomycetes diversity is scarce in this area. Random sampling was used to investigate myxomycetes' diversity and distribution characteristics in this area. One hundred and seventeen species, including three varieties, were obtained, belonging to 28 genera, nine families, and six orders, with Arcyria cinerea and Physarum viride being the dominant species. Moreover, four species and one variety were first reported in China. Twenty-six species and one variety were first reported in Yunnan Province. The species' most commonly utilized substrate for fruiting bodies was decaying wood, and Cribraria was the dominant genus. The species diversity was most abundant in mixed broadleaf-conifer forests. Species similarity between coniferous and broad-leaved forests was much higher than the pairwise comparison of other forest types. NMDS analysis shows that substrate and forest types had insignificant effects on myxomycetes communities, while river valley had a significant effect. The myxomycetes community similarity between river valleys is unrelated to geographical proximity.
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Mixomicetos , Tracheophyta , Humanos , Ríos , China , Bosques , Biodiversidad , ÁrbolesRESUMEN
A new myxomycete species, Didymium arenosum, was described based on morphological evidence and phylogenetic analyses. The species was discovered in the arid region at the confluence of the Badain Jaran desert and Tengger desert on the leaves of Betula platyphylla and was cultivated in a moist chamber culture. Morphologically, the species is distinguished by the greenish-yellow calcium carbonate crystals on the surface and the spores covered with small warts, some of which are connected into a short line. A phylogenetic analysis of D. arenosum strongly supports its classification as a separate clade. The spore to spore agar culture of D. arenosum requires 23 days, and this study provides a detailed description of its life cycle.
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Mixomicetos , Physarida , Mixomicetos/genética , Filogenia , Microscopía Electrónica de Rastreo , Clima Desértico , Esporas ProtozoariasRESUMEN
A new genus and species of myxomycete, Tasmaniomyxa umbilicata, 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 T. umbilicata 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 T. umbilicata at the base of the branch of all lime-containing Physarales, thus justifying its description as a monotypic genus.
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Mixomicetos , Physarida , Humanos , Mixomicetos/genética , Tasmania , Esporas Protozoarias , Australia , FilogeniaRESUMEN
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.
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Amebozoos , Mixomicetos , Tamaño del Genoma , Mixomicetos/genética , Composición de Base , Filogenia , Amebozoos/genéticaRESUMEN
Based on a study of 255 collections from four continents and four floristic kingdoms, we describe 15 new species of the genus Lycogala. The new species, all morphologically close to L. epidendrum, L. exiguum, and L. confusum, 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 L. exiguum and L. confusum 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 L. epidendrum for the globally most abundant species, for which we provide a more precise description and a neotypification. Two formerly described species, L. leiosporum and L. fuscoviolaceum, we consider to be dubious. We do not recognize the species L. terrestre.
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Mixomicetos , Microscopía Electrónica de Rastreo , Mixomicetos/clasificación , Mixomicetos/genética , Mixomicetos/ultraestructura , Esporas Protozoarias/citología , Especificidad de la Especie , ADN Protozoario/genética , Código de Barras del ADN TaxonómicoRESUMEN
BACKGROUND: Physarum polycephalum is an unusual macroscopic myxomycete expressing a large range of glycosyl hydrolases. Among them, enzymes from the GH18 family can hydrolyze chitin, an important structural component of the cell walls in fungi and in the exoskeleton of insects and crustaceans. METHODS: Low stringency sequence signature search in transcriptomes was used to identify GH18 sequences related to chitinases. Identified sequences were expressed in E. coli and corresponding structures modelled. Synthetic substrates and in some cases colloidal chitin were used to characterize activities. RESULTS: Catalytically functional hits were sorted and their predicted structures compared. All share the TIM barrel structure of the GH18 chitinase catalytic domain, optionally fused to binding motifs, such as CBM50, CBM18, and CBM14, involved in sugar recognition. Assessment of the enzymatic activities following deletion of the C-terminal CBM14 domain of the most active clone evidenced a significant contribution of this extension to the chitinase activity. A classification based on module organization, functional and structural criteria of characterized enzymes was proposed. CONCLUSIONS: Physarum polycephalum sequences encompassing a chitinase like GH18 signature share a modular structure involving a structurally conserved catalytic TIM barrels decorated or not by a chitin insertion domain and optionally surrounded by additional sugar binding domains. One of them plays a clear role in enhancing activities toward natural chitin. GENERAL SIGNIFICANCE: Myxomycete enzymes are currently poorly characterized and constitute a potential source for new catalysts. Among them glycosyl hydrolases have a strong potential for valorization of industrial waste as well as in therapeutic field.
Asunto(s)
Quitinasas , Mixomicetos , Physarum polycephalum , Quitinasas/genética , Quitinasas/química , Physarum polycephalum/metabolismo , Mixomicetos/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Quitina/química , AzúcaresRESUMEN
Despite various attempts during the last few decades to establish a natural system for the Myxomycetes, researchers have not yet reached a consensus. One of the most drastic recent proposals is the movement of the genus Lamproderma, an almost a trans-subclass transfer. The traditional subclasses are not supported by current molecular phylogenies, and various higher classifications have been proposed during the last decade. However, the taxonomic characteristics on which the traditional higher classifications were based have not been reinvestigated. In the present study, the key species involved in this transfer, Lamproderma columbinum (the type species of the genus Lamproderma), was assessed using correlational morphological analysis of stereo, light, and electron microscopic images. Correlational analysis of the plasmodium, fruiting body formation, and the mature fruiting bodies revealed that several concepts of taxonomic characteristics that have been used to distinguish higher classifications are questionable. The results of this study indicate that caution is required when interpreting the evolution of morphological traits in Myxomycetes, as the current concepts are vague. The definitions of the taxonomic characteristics need a detailed research, and attention should be paid to the lifecycle timing of observations, before discussing a natural system for Myxomycetes.
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Mixomicetos , Mixomicetos/genética , Filogenia , ReproducciónRESUMEN
The noncellular complex structures of fruiting body produced by a multinucleate large plasmodium are the distinct character of Myxomycetes. Although the fruiting body distinguishes myxomycetes from other amoeboid single-cell organisms, it is unclear how such complex structures arise out of a single cell. The present study investigated the detailed process of fruiting body formation in Lamproderma columbinum, the type species of the genus Lamproderma, at the cellular level. A single cell excretes cellular waste and excess water during the formation of the fruiting body by controlling its shape, secreted materials, and organelle distribution. These excretion phenomena lead to the morphology of the mature fruiting body. The results of this study suggest that the structures of the L. columbinum fruiting body are involved not merely in spore dispersal but also in the process of dehydration and self-cell cleaning of the single cell for the next generation.
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Mixomicetos , Humanos , DeshidrataciónRESUMEN
The myxomycete Fuligo septica, 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 F. septica aethalia, which enabled the isolation, purification, structure elucidation, and biological screening of two avenalumamide pyrones, fuligopyrone (1) and fuligopyrone B (2). While 1 and 2 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 2 to direct sunlight for 5 min resulted in rapid equilibration with a mixture of 2E,4Z-fuligopyrone B (10) and 2Z,4E-fuligopyrone B (11) photoisomers.
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Ascomicetos , Mixomicetos , Animales , Perros , Mixomicetos/química , Rayos Ultravioleta , Cuerpos Fructíferos de los Hongos , AustraliaRESUMEN
Lycogala epidendrum is one of the most widely known myxomycete species and the first-ever discovered representative of this group. Using 687 original DNA sequences from 330 herbarium specimens from Europe, Asia, North and Central America, and Australia, we constructed the first detailed phylogenies of the genus Lycogala, based on two independently inherited genetic markers, the ribosome small subunit 18S rRNA nuclear gene (18S rDNA) and the mitochondrial cytochrome oxidase subunit I gene (COI). In both phylogenies, L. epidendrum appeared to be a polyphyletic group, represented by numerous clades. The four other recognized species of the genus (L. confusum, L. conicum, L. exiguum, and L. flavofuscum) are scattered between branches corresponding to L. epidendrum. A barcode gap analysis revealed 60 18S rDNA phylogroups of L. epidendrum, which are distant from each other not less than from other species of the genus Lycogala. For 18 of these phylogroups with both 18S rDNA and COI sequences available, recombination patterns were analyzed to test for reproductive isolation. In contrast to the results of a simulation assuming panmixis, no crossing between ribosomal and mitochondrial phylogroups was found, thus allowing the conclusion that all tested phylogroups represent biospecies. More than one third (39.6%) of the studied specimens share a single 18S rDNA phylogroup, which we consider to be L. epidendrum s. str. This group displays the broadest geographic distribution and the highest intraspecific genetic variability. Nearly all (93.3%) of the remaining non-singleton 18S rDNA phylogroups are restricted to certain continents or even regions. At the same time, various reproductively isolated phylogroups occur sympatric at a given location.
Asunto(s)
Mixomicetos , Análisis de Secuencia de ADN , Mixomicetos/genética , Marcadores Genéticos , ARN Ribosómico 18S/genética , ADN Ribosómico/genética , FilogeniaRESUMEN
BACKGROUND: Myxomycetes are a group of eukaryotes belonging to Amoebozoa, which are characterized by a distinctive life cycle, including the plasmodium stage and fruit body stage. Plasmodia are all found to be associated with bacteria. However, the information about bacteria diversity and composition in different plasmodia was limited. Therefore, this study aimed to investigate the bacterial diversity of plasmodia from different myxomycetes species and reveal the potential function of plasmodia-associated bacterial communities. RESULTS: The bacterial communities associated with the plasmodia of six myxomycetes (Didymium iridis, Didymium squamulosum, Diderma hemisphaericum, Lepidoderma tigrinum, Fuligo leviderma, and Physarum melleum) were identified by 16S rRNA amplicon sequencing. The six plasmodia harbored 38 to 52 bacterial operational taxonomic units (OTUs) that belonged to 7 phyla, 16 classes, 23 orders, 40 families, and 53 genera. The dominant phyla were Bacteroidetes, Firmicutes, and Proteobacteria. Most OTUs were shared among the six myxomycetes, while unique bacteria in each species only accounted for a tiny proportion of the total OTUs. CONCLUSIONS: Although each of the six myxomycetes plasmodia had different bacterial community compositions, a high similarity was observed in the plasmodia-associated bacterial communities' functional composition. The high enrichment for gram-negative (> 90%) and aerobic (> 99%) bacteria in plasmodia suggest that myxomycetes may positively recruit certain kinds of bacteria from the surrounding environment.
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Mixomicetos , Physarum , Plasmodium , Humanos , Mixomicetos/genética , ARN Ribosómico 16S/genética , Physarum/genética , Bacterias/genéticaRESUMEN
Type specimens of four species of Lepidoderma (Myxomycetes, Amoebozoa)-L. crassipes, L. neoperforatum, L. perforatum, and L. stipitatum-have been studied using an integrative approach including application of traditional taxonomy methods, i.e., morphological study under stereoscopic and compound microscopes, detailed analysis of micromorphological characters using scanning electron microscopy, and molecular analysis by way of Sanger sequencing of molecular markers (nuc 18S rDNA and elongation factor 1-alpha gene, EF1A). Results of the study revealed that L. crassipes is conspecific with L. tigrinum, L. stipitatum is a malformed specimen of Diderma floriforme, whereas L. perforatum and L. neoperforatum represent two well-defined morphologically and genetically separate species. Phylogeny of Physarales shows the polyphyletic character of the genus Lepidoderma. The type species of Lepidoderma clusters together with Diderma, whereas other representatives of this genus form a monophyletic, well-supported clade. The species from this clade are proposed to belong to the genus Polyschismium described by A. Corda in 1842 that is resurrected and emended here. Nine species of Lepidoderma are transferred to Polyschismium. A new key to Didymiaceae including Polyschismium is provided.
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Mixomicetos , ADN Ribosómico/genética , FilogeniaRESUMEN
Early phylogenetic studies refuted most previous assumptions concerning the evolution of the morphological traits in the fruiting bodies of the order Trichiales and did not detect discernible evolutionary patterns, yet they were based on a limited number of species. We infer a new Trichiales phylogeny based on three independently inherited genetic regions (nuclear and mitochondrial), with a fair taxonomic sampling encompassing its broad diversity. Besides, we study the evolutionary history of some key morphological characters. According to the new phylogeny, most fruiting body traits in Trichiales systematics do not represent exclusive synapomorphies or autapomorphies for most monophyletic groups. Instead, the evolution of the features derived from the peridium, stalk, capillitium, and spores showed intricate patterns, and character state transitions occurred rather within- than between clades. Thus, we should consider other evolutionary scenarios instead of assuming the homology of some characters. According to these results, we propose a new classification of Trichiales, including the creation of a new genus, Gulielmina, the resurrection of the family Dictydiaethaliaceae and the genus Ophiotheca, and the proposal of 13 new combinations for species of the genera Arcyria (1), Hemitrichia (2), Ophiotheca (2), Oligonema (4), Gulielmina (3), and Perichaena (1).
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Amoeba , Amebozoos , Ascomicetos , Mixomicetos , Mixomicetos/genética , FilogeniaRESUMEN
Fifty years ago, the enigmatic Brazilian myxomycete-species Didymium aquatile was described and analyzed with respect to the structure of the plasmodium and its spores. In this study, we compare this rare plasmodial slime mold with another, temporarily aquatic taxon from Europe, Didymium nigripes. Phenotypic plasticity of D. nigripes was investigated under various environmental conditions. Large changes in the morphology of the plasmodia were observed. For species identification, characteristics of the fruiting bodies are key features. However, Didymium aquatile was only characterized by its "abnormal" plasmodia, but no molecular data were available. Here, we analyzed DNA-sequences of 22 species of the genera Didymium and Diderma with a focus on this South American taxon via molecular genetics. A comparison of 18S-rDNA-sequences from D. aquatile and 21 other Didymium (and Diderma)-species indicates that D. aquatile is a reproductively isolated morpho-species. Phenotypic plasticity of D. nigripes is documented with respect to plasmodium morphology and the formation of fruiting bodies, as an example of an adaptation of a terrestrial species to aquatic environments.