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PeerJ 2021Although myxomycetes are ubiquitous in terrestrial ecosystems, studies on their distribution and diversity in subtropical humid forests are still lacking. Field...
Although myxomycetes are ubiquitous in terrestrial ecosystems, studies on their distribution and diversity in subtropical humid forests are still lacking. Field collections and moist chamber cultures were conducted from May to October within a two-year period in the Tiantangzhai National Forest Park of China. A total of 1,492 records representing 73 species belonging to 26 genera were obtained, of which 243 records/37 species were from field collections, and 1,249 records/52 species were from moist chamber cultures. Among the specimens obtained by culturing, 896 records/38 species and 353 records/37 species were obtained from living bark and ground litter, respectively. ANOVA showed that the sampling months had significant impacts on collection of myxomycetes from field and those that inhabit litter. An LEfSe analysis indicated that was significantly abundant in August, while and were more abundant in July when collected from field. An RDA analysis showed that temperature was the main factor that affected the litter-inhabiting myxomycetes. The ANOVA indicated that forest type was the significant factor for bark-inhabiting myxomycetes. was primarily obtained from mixed forests, while and were more common in coniferous forests. The RDA analysis indicated that the vegetation, pH, water retention, and elevation were the primary factors that affected the bark-inhabiting myxomycetes.
PubMed: 34527444
DOI: 10.7717/peerj.12059 -
Proceedings of the National Academy of... Sep 2021
Topics: Physarum polycephalum
PubMed: 34470820
DOI: 10.1073/pnas.2105928118 -
Non-coding RNA Jul 2021Nuclear group I introns are restricted to the ribosomal DNA locus where they interrupt genes for small subunit and large subunit ribosomal RNAs at conserved sites in...
Nuclear group I introns are restricted to the ribosomal DNA locus where they interrupt genes for small subunit and large subunit ribosomal RNAs at conserved sites in some eukaryotic microorganisms. Here, the myxomycete protists are a frequent source of nuclear group I introns due to their unique life strategy and a billion years of separate evolution. The ribosomal DNA of the myxomycete was investigated and found to contain seven group I introns, including a direct repeat-containing intron at insertion site S1389 in the small subunit ribosomal RNA gene. We collected, analyzed, and compared 72 S1389 group IC1 introns representing diverse myxomycete taxa. The consensus secondary structure revealed a conserved ribozyme core, but with surprising sequence variations in the guanosine binding site in segment P7. Some S1389 introns harbored large extension sequences in the peripheral region of segment P9 containing direct repeat arrays. These repeats contained up to 52 copies of a putative internal guide sequence motif. Other S1389 introns harbored homing endonuclease genes in segment P1 encoding His-Cys proteins. Homing endonuclease genes were further interrupted by small spliceosomal introns that have to be removed in order to generate the open reading frames. Phylogenetic analyses of S1389 intron and host gene indicated both vertical and horizontal intron transfer during evolution, and revealed sporadic appearances of direct repeats, homing endonuclease genes, and guanosine binding site variants among the myxomycete taxa.
PubMed: 34449660
DOI: 10.3390/ncrna7030043 -
Bio Systems Oct 2021This research addresses the interactions between the unicellular slime mold Physarum polycephalum and a red yeast in a spatial ecosystem over week-long imaging...
This research addresses the interactions between the unicellular slime mold Physarum polycephalum and a red yeast in a spatial ecosystem over week-long imaging experiments. An inverse relationship between the growth rates of both species is shown, where P. polycephalum has positive growth when the red yeast has a negative growth rate and vice versa. The data also captures successional and oscillatory dynamics between both species. An advanced image analysis methodology for semantic segmentation is used to quantify population density over time, for all components of the ecosystem. We suggest that P. polycephalum is capable of exhibiting a sustainable feeding strategy by depositing a nutritive slime trail, allowing yeast to serve as a periodic food source. This opens a new direction of P. polycephalum research, where the population dynamics of spatial ecosystems can be readily quantified and complex ecological dynamics can be studied.
Topics: Deep Learning; Ecosystem; Microbiological Phenomena; Physarum polycephalum; Population Dynamics
PubMed: 34271083
DOI: 10.1016/j.biosystems.2021.104483 -
Advanced Materials (Deerfield Beach,... Aug 2021The unicellular protist Physarum polycephalum is an important emerging model for understanding how aneural organisms process information toward adaptive behavior. Here,...
The unicellular protist Physarum polycephalum is an important emerging model for understanding how aneural organisms process information toward adaptive behavior. Here, it is revealed that Physarum can use mechanosensation to reliably make decisions about distant objects in its environment, preferentially growing in the direction of heavier, substrate-deforming, but chemically inert masses. This long-range sensing is abolished by gentle rhythmic mechanical disruption, changing substrate stiffness, or the addition of an inhibitor of mechanosensitive transient receptor potential channels. Additionally, it is demonstrated that Physarum does not respond to the absolute magnitude of strain. Computational modeling reveales that Physarum may perform this calculation by sensing the fraction of its perimeter that is distorted above a threshold substrate strain-a fundamentally novel method of mechanosensation. Using its body as both a distributed sensor array and computational substrate, this aneural organism leverages its unique morphology to make long-range decisions. Together, these data identify a surprising behavioral preference relying on biomechanical features and quantitatively characterize how the Physarum exploits physics to adaptively regulate its growth and shape.
Topics: Agar; Animals; Biomechanical Phenomena; Chemotaxis; Computer Simulation; Feedback, Physiological; Gravity Sensing; In Vitro Techniques; Movement; Photic Stimulation; Physarum polycephalum; Sensation; Spatial Navigation; Stress, Mechanical
PubMed: 34263487
DOI: 10.1002/adma.202008161 -
Mycologia 2021Five specimens, initially presumed to be or , were collected from Jilin Province and the Inner Mongolia Autonomous Region in China, but all five turned out to represent...
Five specimens, initially presumed to be or , were collected from Jilin Province and the Inner Mongolia Autonomous Region in China, but all five turned out to represent a new aethaloid species, . This new species is characterized by pseudocapillitia without capillitia and an aethalioid fruiting body, features that are morphologically distinct from those of any other species of . To assess the phylogenetic relationships between and other members of and in the Didymiaceae, sequences from two nonoverlapping targeted portions of nuc 18S rDNA (~450 bp and ~1050 bp) and translation elongation factor 1-alpha () were obtained and analyzed. The results indicate that forms a single clade separate from other species of and the clade that contains , which strongly supports the identification of the five specimens as a new species.
Topics: Ascomycota; China; DNA, Ribosomal; Phylogeny; Physarida
PubMed: 34236946
DOI: 10.1080/00275514.2021.1922224 -
AMB Express Jun 2021Given the emerging multidrug-resistant pathogens, the number of effective antimicrobial agents to deal with the threat of bacterial and fungal resistance has fallen... (Review)
Review
Given the emerging multidrug-resistant pathogens, the number of effective antimicrobial agents to deal with the threat of bacterial and fungal resistance has fallen dramatically. Therefore, the critical solution to deal with the missing effective antibiotics is to research new sources or new synthetic antibiotics. Natural products have different advantages to be considered antimicrobial agents. There are different natural sources for antimicrobial agents, such as bacteria, fungi, algae, slime molds, and plants. This article has focused on antibiotics from slime molds, especially Myxomycetes. The reason why slime molds have been chosen to be studied is their unique bioactive metabolites, especially over the past couple of decades. Some of those metabolites have been demonstrated to possess antibiotic activities. Hence, this article has focused on the potential of these creatures as an alternative source of antibiotics.
PubMed: 34160704
DOI: 10.1186/s13568-021-01251-3 -
Current Biology : CB Jul 2021Spliceosomal introns interrupt nuclear genes and are removed from RNA transcripts ("spliced") by machinery called spliceosomes. Although the vast majority of...
Spliceosomal introns interrupt nuclear genes and are removed from RNA transcripts ("spliced") by machinery called spliceosomes. Although the vast majority of spliceosomal introns are removed by the so-called major (or "U2") spliceosome, diverse eukaryotes also contain a rare second form, the minor ("U12") spliceosome, and associated ("U12-type") introns. In all characterized species, U12-type introns are distinguished by several features, including being rare in the genome (∼0.5% of all introns), containing extended evolutionarily conserved splicing motifs, being generally ancient, and being inefficiently spliced. Here, we report a remarkable exception in the slime mold Physarum polycephalum. The P. polycephalum genome contains >20,000 U12-type introns-25 times more than any other species-enriched in a diversity of non-canonical splice boundaries as well as transformed splicing signals that appear to have co-evolved with the spliceosome due to massive gain of efficiently spliced U12-type introns. These results reveal an unappreciated dynamism of minor spliceosomal introns and spliceosomal introns in general.
Topics: Introns; Physarum polycephalum; RNA Splicing; RNA, Small Nuclear; Spliceosomes
PubMed: 34015249
DOI: 10.1016/j.cub.2021.04.050 -
Experimental & Applied Acarology Jun 2021Tyrophagus putrescentiae (Schrank), commonly known as the cereal mite, cheese mite, or ham mite, is a cosmopolitan species reported from various environments in the...
Tyrophagus putrescentiae (Schrank), commonly known as the cereal mite, cheese mite, or ham mite, is a cosmopolitan species reported from various environments in the wild, including soil, plant material and vertebrate nests. It has also been recognized as a common pest of food storages, mycological collections as well as plant and invertebrate laboratory cultures. Laboratory observations indicate that T. putrescentiae feeds on a large range of dermatophytes, yeasts and molds. We have observed the interspecific relation between this mite and several species of true slime molds (Mycetozoa) under laboratory conditions, which confirms the very broad spectrum of feeding habits of T. putrescentiae. Mycetozoans were grown in semi-sterile in vitro cultures and fed with oat flour or oat flakes. Tyrophagus putrescentiae displayed affinity to all macroscopically identifiable stages of the life cycle of Fuligo septica (L.) F.H. Wigg, Physarum polycephalum Schwein and the Didymium sp. complex [Didymium iridis (Ditmar) Fr., Didymium nigripes (Link) Fr. and Didymium bahiense Gottsb.]: live, decaying or dead plasmodia, sporangia, aethalia, spores and sclerotia. The relation carrying symptoms of various types of interspecific interaction, is hypothesized to form an evolutionarily young phenomenon, which not only identifies a new aspect of mycetozoal biology, but also presents the cereal mite as a species of high adaptive potential.
Topics: Acaridae; Accidents; Animals; Life Cycle Stages; Physarum polycephalum; Yeasts
PubMed: 33970406
DOI: 10.1007/s10493-021-00608-4 -
Protist Apr 2021Myxomycetes constitute one of the major lineages within the supergroup Amoebozoa. At the end of their life cycles, most myxomycetes produce spore-bearing fruiting...
Myxomycetes constitute one of the major lineages within the supergroup Amoebozoa. At the end of their life cycles, most myxomycetes produce spore-bearing fruiting bodies, in which additional structures develop, like the capillitium, a system of sterile filaments intermingled with the spores. The capillitium is a relevant structure in the taxonomy of the order Trichiales, the target group in this study. However, the introduction of molecular phylogenies in Myxomycetes systematics is challenging our comprehension of this structure. We studied the capillitium of 25 species representing nine Trichiales genera, with both scanning and transmission electron microscopy. In this order, the capillitium showed higher diversity than so far recognized. Thus, we distinguished and described five capillitium types and two subtypes based on the presence or absence of a lumen and the wall ultrastructure. These types followed the evolutionary history reported in recent phylogenies, although not all of them defined monophyletic groups. Besides, the spiral ornamentation, which most taxonomists considered to have appeared once, occurred in three different capillitium types. The ultrastructural approaches in Myxomycetes systematics enable the reconsideration of their morphological features in the new phylogenetic scenario.
Topics: Amoebozoa; Classification; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Phylogeny
PubMed: 33964593
DOI: 10.1016/j.protis.2021.125805