-
Journal of Applied Physiology... Jun 2008
Topics: Adaptation, Physiological; Amoeba; Animals; Biological Evolution; Comprehension; Energy Metabolism; Extinction, Biological; Humans; Models, Biological; Myxomycetes; Nonlinear Dynamics; Selection, Genetic; Systems Biology; Thermodynamics
PubMed: 18584786
DOI: 10.1152/japplphysiol.zdg-7945-vpcomm.2008 -
Journal of Applied Physiology... Jun 2008
Topics: Adaptation, Physiological; Amoeba; Animals; Biological Evolution; Comprehension; Energy Metabolism; Extinction, Biological; Humans; Models, Biological; Myxomycetes; Nonlinear Dynamics; Selection, Genetic; Systems Biology; Thermodynamics
PubMed: 18584789
DOI: 10.1152/japplphysiol.zdg-7945-vpcomm.2008 -
BMC Microbiology Dec 2022Myxomycetes are a group of eukaryotes belonging to Amoebozoa, which are characterized by a distinctive life cycle, including the plasmodium stage and fruit body stage....
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.
Topics: Humans; Myxomycetes; RNA, Ribosomal, 16S; Physarum; Bacteria; Plasmodium
PubMed: 36544088
DOI: 10.1186/s12866-022-02725-5 -
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 -
Theory in Biosciences = Theorie in Den... Sep 2022Fifty years ago, the enigmatic Brazilian myxomycete-species Didymium aquatile was described and analyzed with respect to the structure of the plasmodium and its spores....
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.
Topics: Adaptation, Physiological; Myxomycetes; Phylogeny
PubMed: 36029433
DOI: 10.1007/s12064-022-00375-9 -
Journal of Visualized Experiments : JoVE Nov 2017Our research is aimed at gaining a better understanding of the electronic properties of organisms in order to engineer novel bioelectronic systems and computing...
Our research is aimed at gaining a better understanding of the electronic properties of organisms in order to engineer novel bioelectronic systems and computing architectures based on biology. This specific paper focuses on harnessing the unicellular slime mold Physarum polycephalum to develop bio-memristors (or biological memristors) and bio-computing devices. The memristor is a resistor that possesses memory. It is the 4th fundamental passive circuit element (the other three are the resistor, the capacitor, and the inductor), which is paving the way for the design of new kinds of computing systems; e.g., computers that might relinquish the distinction between storage and a central processing unit. When applied with an AC voltage, the current vs. voltage characteristic of a memristor is a pinched hysteresis loop. It has been shown that P. polycephalum produces pinched hysteresis loops under AC voltages and displays adaptive behavior that is comparable with the functioning of a memristor. This paper presents the method that we developed for implementing bio-memristors with P. polycephalum and introduces the development of a receptacle to culture the organism, which facilitates its deployment as an electronic circuit component. Our method has proven to decrease growth time, increase component lifespan, and standardize electrical observations.
Topics: Biomimetics; Electric Impedance; Electrophysiological Phenomena; Myxomycetes
PubMed: 29155754
DOI: 10.3791/56076 -
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 -
Anais Da Academia Brasileira de Ciencias 2024The family Physaraceae (Physarales, Myxomycetes) is represented in Brazil by eight genera and 75 species. Based on data obtained from the GBIF, SpeciesLink, Flora and...
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.
Topics: Myxomycetes; Brazil; Ecosystem
PubMed: 38451623
DOI: 10.1590/0001-3765202420220698 -
Proceedings of the National Academy of... Mar 2021The concept of memory is traditionally associated with organisms possessing a nervous system. However, even very simple organisms store information about past...
The concept of memory is traditionally associated with organisms possessing a nervous system. However, even very simple organisms store information about past experiences to thrive in a complex environment-successfully exploiting nutrient sources, avoiding danger, and warding off predators. How can simple organisms encode information about their environment? We here follow how the giant unicellular slime mold responds to a nutrient source. We find that the network-like body plan of the organism itself serves to encode the location of a nutrient source. The organism entirely consists of interlaced tubes of varying diameters. Now, we observe that these tubes grow and shrink in diameter in response to a nutrient source, thereby imprinting the nutrient's location in the tube diameter hierarchy. Combining theoretical model and experimental data, we reveal how memory is encoded: a nutrient source locally releases a softening agent that gets transported by the cytoplasmic flows within the tubular network. Tubes receiving a lot of softening agent grow in diameter at the expense of other tubes shrinking. Thereby, the tubes' capacities for flow-based transport get permanently upgraded toward the nutrient location, redirecting future decisions and migration. This demonstrates that nutrient location is stored in and retrieved from the networks' tube diameter hierarchy. Our findings explain how network-forming organisms like slime molds and fungi thrive in complex environments. We here identify a flow networks' version of associative memory-very likely of relevance for the plethora of living flow networks as well as for bioinspired design.
Topics: Cytoplasm; Models, Biological; Physarum polycephalum
PubMed: 33619174
DOI: 10.1073/pnas.2007815118 -
Biochimica Et Biophysica Acta. General... Jun 2023Physarum polycephalum is an unusual macroscopic myxomycete expressing a large range of glycosyl hydrolases. Among them, enzymes from the GH18 family can hydrolyze...
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.
Topics: Chitinases; Physarum polycephalum; Myxomycetes; Escherichia coli; Chitin; Sugars
PubMed: 36933625
DOI: 10.1016/j.bbagen.2023.130343