Various dictyostelids from the environment can produce multilamellar bodies

2020 ◽  
Vol 66 (12) ◽  
pp. 679-688
Author(s):  
Alicia F. Durocher ◽  
Cynthia Gagné-Thivierge ◽  
Steve J. Charette
Keyword(s):  
Cell Communication ◽  
Laboratory Strain ◽  
Food Storage ◽  
Epifluorescence Microscopy ◽  
Free Living ◽  
Multicellular Development ◽  
Multilamellar Bodies ◽  
Transmission Electron ◽  
Axenic Conditions ◽  
Social Amoebae

Multilamellar bodies (MLBs), structures composed of concentric membrane layers, are known to be produced by different protozoa, including species of ciliates, free-living amoebae, and Dictyostelium discoideum social amoebae. Initially believed to be metabolic waste, potential roles like cell communication and food storage have been suggested for D. discoideum MLBs, which could be useful for the multicellular development of social amoebae and as a food source. However, among dictyostelids, this phenomenon has only been observed with D. discoideum, and mainly with laboratory strains grown in axenic conditions. It was thought that other social amoebae may also produce MLBs. Four environmental social amoeba isolates were characterized. All strains belong to the Dictyostelium genus, including some likely to be Dictyostelium giganteum. They have distinctive phenotypes comprising their growth rate on Klebsiella aerogenes lawns and the morphology of their fruiting bodies. They all produce MLBs like those produced by a D. discoideum laboratory strain when grown on K. aerogenes lawns, as revealed by analysis using the H36 antibody in epifluorescence microscopy as well as by transmission electron microscopy. Consequently, this study shows that MLBs are produced by various dictyostelid species, which further supports a role for MLBs in the lifestyle of amoebae.

scholarly journals Genomic insights into the evolutionary origin of Myxozoa within Cnidaria

2015 ◽  
Vol 112 (48) ◽  
pp. 14912-14917 ◽  
Author(s):  
E. Sally Chang ◽  
Moran Neuhof ◽  
Nimrod D. Rubinstein ◽  
Arik Diamant ◽  
Hervé Philippe ◽  
...  
Keyword(s):  
Genome Size ◽  
Cell Communication ◽  
Evolutionary Origin ◽  
Phylogenomic Analysis ◽  
Sea Anemones ◽  
Free Living ◽  
Multicellular Development ◽  
Phylogenetic Studies ◽  
Close Relationship ◽  
Polypodium Hydriforme

The Myxozoa comprise over 2,000 species of microscopic obligate parasites that use both invertebrate and vertebrate hosts as part of their life cycle. Although the evolutionary origin of myxozoans has been elusive, a close relationship with cnidarians, a group that includes corals, sea anemones, jellyfish, and hydroids, is supported by some phylogenetic studies and the observation that the distinctive myxozoan structure, the polar capsule, is remarkably similar to the stinging structures (nematocysts) in cnidarians. To gain insight into the extreme evolutionary transition from a free-living cnidarian to a microscopic endoparasite, we analyzed genomic and transcriptomic assemblies from two distantly related myxozoan species, Kudoa iwatai and Myxobolus cerebralis, and compared these to the transcriptome and genome of the less reduced cnidarian parasite, Polypodium hydriforme. A phylogenomic analysis, using for the first time to our knowledge, a taxonomic sampling that represents the breadth of myxozoan diversity, including four newly generated myxozoan assemblies, confirms that myxozoans are cnidarians and are a sister taxon to P. hydriforme. Estimations of genome size reveal that myxozoans have one of the smallest reported animal genomes. Gene enrichment analyses show depletion of expressed genes in categories related to development, cell differentiation, and cell–cell communication. In addition, a search for candidate genes indicates that myxozoans lack key elements of signaling pathways and transcriptional factors important for multicellular development. Our results suggest that the degeneration of the myxozoan body plan from a free-living cnidarian to a microscopic parasitic cnidarian was accompanied by extreme reduction in genome size and gene content.

Separation of Extracellular Vesicles by DNA-Directed Immunocapturing Followed by Enzymatic Release

2020 ◽  
Author(s):  
Dario Brambilla ◽  
Laura Sola ◽  
Elisa Chiodi ◽  
Natasa Zarovni ◽  
Diogo Fortunato ◽  
...  
Keyword(s):  
Cell Culture ◽  
Extracellular Vesicles ◽  
Culture Media ◽  
Biological Fluids ◽  
Imaging Techniques ◽  
Cell Communication ◽  
Disease Diagnosis ◽  
Cell Culture Supernatant ◽  
Transmission Electron ◽  
Downstream Analysis

Extracellular vesicles (EVs) have attracted great interest among researchers due to their role in cell-cell communication, disease diagnosis, and drug delivery. In spite of their potential in the medical field, there is no consensus on the best method for separating microvesicles from cell culture supernatant and complex biological fluids. Obtaining a good recovery yield and preserving physical characteristics is critical for the diagnostic and therapeutic use of EVs. The separation is made complex by the fact that blood and cell culture media, contain a large number of nanoparticles in the same size range. Methods that exploit immunoaffinity capture provide high purity samples and overcome the issues of currently used separation methods. However, the release of captured nanovesicles requires harsh conditions that hinder their use in certain types of downstream analysis. Herein, a novel capture and release approach for small extracellular vesicles (sEVs), based on DNAdirected immobilization of antiCD63 antibody is presented. The flexible DNAlinker increases the capture efficiency and allows releasing of EVs by exploiting the endonucleasic activity of DNAse I. This separation protocol works under mild conditions, enabling the release of intact vesicles that can be successfully analyzed by imaging techniques. In this article sEVs recovered from plasma were characterized by established techniques for EVs analysis including nanoparticle tracking and transmission electron microscopy.<br>

Ultrastructures of Epibiotic Suctorian, Tokophrya huangmeiensis 

Zootaxa ◽  
2018 ◽  
Vol 4521 (1) ◽  
pp. 145
Author(s):  
URFA BIN TAHIR ◽  
DENG QIONG ◽  
WANG ZHE ◽  
LI SEN ◽  
LIU YANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Structural Changes ◽  
Small Subunit ◽  
Free Living ◽  
Transmission Electron ◽  
Small Subunit Ribosomal Dna ◽  
Ribosomal Dna Sequence ◽  
Freshwater Ciliates

Tokophrya species are either free-living or facultative ectosymbiotic suctorians associated with copepods, isopods, mysids, decapods and amphipods. Tokophrya huangmeiensis in particular is found to be epizoic with the redclaw crayfish Cherax quadricarinatus Von Martens, 1868, which has been observed as part of an ongoing investigation of freshwater ciliates biodiversity in Huanggang, Hubei, China (Tahir et al. 2017). This first study on T. huangmeiensis based on morphological features using light microscopy and small subunit ribosomal DNA sequence (Tahir et al. 2017), suggested that more detailed descriptions on the physiological and structural changes of this species should be done. Thus, in this study, we looked at the ultrastructures of T. huangmeiensis using electron microscopy, including both scanning (SEM) and transmission electron microscopy (TEM). 

scholarly journals Novel 5′-Norcarbocyclic Pyrimidine Derivatives as Antibacterial Agents

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3069 ◽  
Author(s):  
Anastasia Khandazhinskaya ◽  
Liudmila Alexandrova ◽  
Elena Matyugina ◽  
Pavel Solyev ◽  
Olga Efremenkova ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Multiple Drug Resistance ◽  
Laboratory Strain ◽  
Clinical Strain ◽  
Multiple Drug ◽  
Bacterial Cells ◽  
Transmission Electron ◽  
Virulent Strains ◽  
Derivatives Of ◽  
Strain H37rv

A series of novel 5′-norcarbocyclic derivatives of 5-alkoxymethyl or 5-alkyltriazolyl-methyl uracil were synthesized and the activity of the compounds evaluated against both Gram-positive and Gram-negative bacteria. The growth of Mycobacterium smegmatis was completely inhibited by the most active compounds at a MIC99 of 67 μg/mL (mc2155) and a MIC99 of 6.7–67 μg/mL (VKPM Ac 1339). Several compounds also showed the ability to inhibit the growth of attenuated strains of Mycobacterium tuberculosis ATCC 25177 (MIC99 28–61 μg/mL) and Mycobacterium bovis ATCC 35737 (MIC99 50–60 μg/mL), as well as two virulent strains of M. tuberculosis; a laboratory strain H37Rv (MIC99 20–50 μg/mL) and a clinical strain with multiple drug resistance MS-115 (MIC99 20–50 μg/mL). Transmission electron microscopy (TEM) evaluation of M. tuberculosis H37Rv bacterial cells treated with one of the compounds demonstrated destruction of the bacterial cell wall, suggesting that the mechanism of action for these compounds may be related to their interactions with bacteria cell walls.

scholarly journals Isolation and Identification of Exosomes from Feline Plasma, Urine and Adipose-Derived Mesenchymal Stem Cells

2021 ◽  
Author(s):  
Dongsheng Li ◽  
Huina Luo ◽  
Huimin Ruan ◽  
Zhisheng Chen ◽  
Shengfeng Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Transmembrane Protein ◽  
Cell Communication ◽  
Phospholipid Bilayer ◽  
Differential Centrifugation ◽  
Isolation And Identification ◽  
Feasible Method ◽  
Transmission Electron ◽  
Mediate Cell

Abstract Background: Exosomes, internal proteins, lipids, and nucleic acids coated by phospholipid bilayer membranes, are one type of small extracellular vesicles, which can mediate cell-cell communication. In recent years, exosomes have gained considerable scientific interest due to their widely applied prospect in the diagnosis and therapeutics of human and animal diseases. In this study, we describe for the first time a feasible method designed to isolate and characterize exosomes from feline plasma, urine and adipose-derived mesenchymal stem cells. Results: Exosomes from feline plasma, urine and adipose-derived mesenchymal stem cells were successfully isolated by differential centrifugation. Quantification and sizing of exosomes were assessed by transmission electron microscopy, flow nano analysis and western blotting. Detected particles showed the normal size (30-100 nm) and morphology described for exosomes, as well as presence of the transmembrane protein (TSG101, CD9, CD63, and CD81) known as exosomal marker.Conclusions: The results suggest that differential centrifugation is a feasible method for isolation of exosomes from different types of feline samples. Moreover, these exosomes can be used to further diagnosis and therapeutics in veterinary pre-clinical and clinical studies.

scholarly journals Wild Dictyostelium discoideum social amoebae show plastic responses to the presence of nonrelatives during multicellular development

2020 ◽  
Vol 10 (3) ◽  
pp. 1119-1134
Author(s):  
Suegene Noh ◽  
Lauren Christopher ◽  
Joan E. Strassmann ◽  
David C. Queller
Keyword(s):  
Dictyostelium Discoideum ◽  
Multicellular Development ◽  
Plastic Responses ◽  
Social Amoebae

scholarly journals Behavior of Yersinia enterocolitica in the Presence of the Bacterivorous Acanthamoeba castellanii

2013 ◽  
Vol 79 (20) ◽  
pp. 6407-6413 ◽  
Author(s):  
E. Lambrecht ◽  
J. Baré ◽  
I. Van Damme ◽  
W. Bert ◽  
K. Sabbe ◽  
...  
Keyword(s):  
Yersinia Enterocolitica ◽  
Pathogenic Bacteria ◽  
Acanthamoeba Castellanii ◽  
Ecological Niches ◽  
Free Living ◽  
Content Type ◽  
Food Borne ◽  
Transmission Electron ◽  
Set Up ◽  
The Impact

ABSTRACTFree-living protozoa play an important role in the ecology and epidemiology of human-pathogenic bacteria. In the present study, the interaction betweenYersinia enterocolitica, an important food-borne pathogen, and the free-living amoebaAcanthamoeba castellaniiwas studied. Several cocultivation assays were set up to assess the resistance ofY. enterocoliticatoA. castellaniipredation and the impact of environmental factors and bacterial strain-specific characteristics. Results showed that allY. enterocoliticastrains persist in association withA. castellaniifor at least 14 days, and associations withA. castellaniienhanced survival ofYersiniaunder nutrient-rich conditions at 25°C and under nutrient-poor conditions at 37°C. Amoebae cultivated in the supernatant of oneYersiniastrain showed temperature- and time-dependent permeabilization. Intraprotozoan survival ofY. enterocoliticadepended on nutrient availability and temperature, with up to 2.8 log CFU/ml bacteria displaying intracellular survival at 7°C for at least 4 days in nutrient-rich medium. Transmission electron microscopy was performed to locate theYersiniacells inside the amoebae. AsYersiniaandAcanthamoebashare similar ecological niches, this interaction identifies a role of free-living protozoa in the ecology and epidemiology ofY. enterocolitica.

scholarly journals Microsporidian Infection in a Free-Living Marine Nematode

2012 ◽  
Vol 11 (12) ◽  
pp. 1544-1551 ◽  
Author(s):  
A. M. Ardila-Garcia ◽  
N. M. Fast
Keyword(s):  
Marine Nematode ◽  
Free Living ◽  
Content Type ◽  
Infection Pattern ◽  
Transmission Electron ◽  
Muscle Tissues ◽  
Natural Hosts ◽  
In The Wild ◽  
Microsporidian Infection

ABSTRACT Microsporidia are unicellular fungi that are obligate endoparasites. Although nematodes are one of the most abundant and diverse animal groups, the only confirmed report of microsporidian infection was that of the “nematode killer” ( Nematocida parisii ). N. parisii was isolated from a wild Caenorhabditis sp. and causes an acute and lethal intestinal infection in a lab strain of Caenorhabditis elegans . We set out to characterize a microsporidian infection in a wild nematode to determine whether the infection pattern of N. parisii in the lab is typical of microsporidian infections in nematodes. We describe a novel microsporidian species named Sporanauta perivermis (marine spore of roundworms) and characterize its infection in its natural host, the free-living marine nematode Odontophora rectangula. S. perivermis is not closely related to N. parisii and differs strikingly in all aspects of infection. Examination by transmission electron microscopy (TEM) revealed that the infection was localized in the hypodermal and muscle tissues only and did not involve the intestines. Fluorescent in situ hybridization (FISH) confirmed infection in the muscle and hypodermis, and surprisingly, it also revealed that the parasite infects O. rectangula eggs, suggesting a vertical mode of transmission. Our observations highlight the importance of studying parasites in their natural hosts and indicate that not all nematode-infecting microsporidia are “nematode killers”; instead, microsporidiosis can be more versatile and chronic in the wild.

scholarly journals Abundance and Spatial Distribution of Aerobic Anoxygenic Phototrophic Bacteria in Tama River, Japan

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 150
Author(s):  
Yuki Sato-Takabe ◽  
Setsuko Hirose ◽  
Tomoyuki Hori ◽  
Satoshi Hanada
Keyword(s):  
Spatial Distribution ◽  
Phototrophic Bacteria ◽  
Anoxygenic Phototrophic Bacteria ◽  
Epifluorescence Microscopy ◽  
Free Living ◽  
Aerobic Anoxygenic Phototrophic Bacteria ◽  
Riverine Environment ◽  
Global Oceans ◽  
Total Bacteria ◽  
Aggregation Form

Aerobic anoxygenic phototrophic bacteria (AAnPB) are widely distributed and regarded as key players driving the carbon cycle in surface water of global oceans, coastal and estuary areas and in other freshwater environments (e.g., ponds and lakes). However, the abundance and spatial distribution of AAnPB in rivers is much less well-known. Here we investigated the variation of the absolute cell abundances of the total bacteria, AAnPB and cyanobacteria, at four different sites in Tama River, Japan, and the spatial distribution (i.e., free-living or particle-attached existence form) of AAnPB at two out of the four sites using infra-red epifluorescence microscopy. Free-living cell abundances for the total bacteria, AAnPB and cyanobacteria were 1.6–3 × 105, 1.5–4.4 × 104 and <3.2 × 104 cells mL−1, respectively. The free-living AAnPB accounted for 6.1%–19.6% of the total bacterial abundance in the river. The peaks of the AAnPB and cyanobacteria abundances were found at the same site, suggesting that the AAnPB could potentially coexist with cyanobacteria. Meanwhile, the particle-attached AAnPB were observed at the two sites of the river, accounting for 52.2% of the total bacteria abundance in the particle. Our results showed the existence and aggregation form of AAnPB in the riverine environment.

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