-
Optics Express Feb 2024Brilliant colors in nature arise from the interference of light with periodic nanostructures resulting in structural color. While such biological photonic structures...
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.
Topics: Myxomycetes; Amoebozoa; Calcium; Nanostructures; Photons
PubMed: 38439270
DOI: 10.1364/OE.511875 -
Protist Apr 2024The nivicolous species of the genus Diderma are challenging to identify, and there are several competing views on their delimitation. We analyzed 102 accessions of...
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.
Topics: Myxomycetes; DNA Barcoding, Taxonomic; Bayes Theorem; Phylogeny; DNA, Ribosomal
PubMed: 38368650
DOI: 10.1016/j.protis.2024.126023 -
PeerJ 2024A new myxomycete species, , was described based on morphological evidence and phylogenetic analyses. The species was discovered in the arid region at the confluence of...
A new myxomycete species, , 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 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 strongly supports its classification as a separate clade. The spore to spore agar culture of . requires 23 days, and this study provides a detailed description of its life cycle.
Topics: Myxomycetes; Phylogeny; Microscopy, Electron, Scanning; Desert Climate; Spores, Protozoan; Physarida
PubMed: 38213774
DOI: 10.7717/peerj.16725 -
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 -
Distribution characteristics and diversity of myxomycetes in three parallel rivers in Yunnan, China.PloS One 2024Three 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...
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.
Topics: Humans; Myxomycetes; Rivers; China; Forests; Biodiversity; Tracheophyta; Trees
PubMed: 38165993
DOI: 10.1371/journal.pone.0293260 -
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 -
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 -
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 -
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 -
The Science of the Total Environment Nov 2023The bright coniferous forest area in the cold temperate zone of China is a terrestrial ecosystem primarily dominated by low mountain Larix gmelinii trees. Limited...
The bright coniferous forest area in the cold temperate zone of China is a terrestrial ecosystem primarily dominated by low mountain Larix gmelinii trees. Limited information is available regarding the assembly mechanisms and interactions of microbial communities in the soil in this region. This study employed high-throughput techniques to obtain DNA from myxomycetes, bacteria, and fungi in the soil, evaluated their diversity in conjunction with environmental factors, associated them with the assembly process, and explored the potential interaction relationships between these microorganisms. The findings of our study showed that environmental factors had a more significant influence on the α and β diversity of bacteria compared to myxomycetes and fungi. Microbial communities were influenced by environmental selection and geographical diffusion, although environmental selection appeared to have a more significant impact than geographical diffusion. Our study suggested that different microorganisms exhibited unique evolutionary patterns and may have different assembly modes within phylogenetic groups. Myxomycetes and fungi exhibited a similar assembly process that was mainly influenced by stochastic dispersal limitation and drift. In contrast, bacteria's assembly process was primarily influenced by stochastic drift and deterministic homogeneous selection. The community of myxomycetes and fungi is greatly influenced by spatial distribution and random events, while bacteria have a relatively stable population composition in specific regions and may also be subject to environmental constraints. Finally, this study revealed that Humicolopsis cephalosporioides, a fungus that exclusively resided in cold environments, may play a critical role as a keystone species in maintaining molecular ecological networks and was considered a core member of the microbiome.
Topics: Soil; Ecosystem; Phylogeny; Tracheophyta; Soil Microbiology; Forests; Fungi
PubMed: 37437627
DOI: 10.1016/j.scitotenv.2023.165429