Virus-Like and Membrane-Bound Particles in the Venom Apparatus of a Parasitoid Wasp (Hymenoptera:Braconidae)

1981 ◽  
Vol 39 ◽  
pp. 610-611
Author(s):  
Karthryn M. Edson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Reproductive System ◽  
Inner Core ◽  
Parasitoid Wasp ◽  
Accessory Gland ◽  
Secretory Cells ◽  
Transmission Electron ◽  
Membrane Bound ◽  
Secretory Apparatus

Successful parasitism of a host by a parasitoid wasp may be aided by secretions from the venom apparatus, an accessory gland of the female parasitoid's reproductive system. In the present study, transmission electron microscopy of the venom apparatus of Meteorus leviventris reveals virus-like and membrane-bound particles which may influence successful parasitism of the host. This is the first evidence of such particles within the venom apparatus of a parasitoid.The venom apparatus of M. leviventris consists of a venom reservoir with two highly ramified gland filaments attached to it by a common duct.TEM of the secretory cells of the gland filaments reveals particles approximately 50 nm in diameter contained within a cytoplasmic stroma (Fig. 1). These virus-like particles (VLP) have a dense inner core and a hexagonal congifuration. Similar particles are found free within the cytoplasm or associated with vacuoles (Fig. 2).Secretory cells of the gland filaments contain a secretory apparatus which consists of an array of microvilli converging on a central lumen (Fig. 3).

scholarly journals Infection With a Novel Rickettsiella Species in Emperor Scorpions (Pandinus imperator)

2020 ◽  
Vol 57 (6) ◽  
pp. 858-870
Author(s):  
Sushan Han ◽  
Aníbal G. Armién ◽  
Janet E. Hill ◽  
Champika Fernando ◽  
Dan S. Bradway ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rapid Progression ◽  
Protein Coding ◽  
Hematopoietic Organ ◽  
Transmission Electron ◽  
History Of ◽  
Gross Lesions ◽  
Membrane Bound ◽  
Methenamine Silver

Rickettsiella infection was diagnosed in 4 adult emperor scorpions ( Pandinus imperator) from 2 different collections over a 3-year period. One case had a 2-day history of weakness, failure to lift the tail, or respond to stimulation, with rapid progression to death. The other 3 cases were found dead. There were no gross lesions, but histologically the hemolymphatic vasculature and sinuses, presumed hematopoietic organ, heart, midgut and midgut diverticula, nerves, and skeletal muscle were infiltrated with phagocytic and granular hemocytes with necrosis. Phagocytic hemocytes contained abundant intracellular microorganisms that were Fite’s acid-fast-positive, Macchiavello-positive, variably gram-positive or gram-negative, and Grocott’s methenamine silver-negative. By transmission electron microscopy, hemocytes contained numerous phagocytic vacuoles with small dense bacterial forms (mean 0.603 × 0.163 μm) interspersed with large bacterial forms (mean 1.265 × 0.505 μm) and few intermediary forms with electron-dense nucleoids and membrane-bound crystalline arrays (average 4.72 μm). Transmission electron microscopy findings were consistent with bacteria of the family Coxiellaceae. Based on sequencing the 16S ribosomal RNA gene, the identity was confirmed as Rickettsiella, and phylogenetic analysis of protein-coding genes gidA, rspA, and sucB genes suggested the emperor scorpion pathogen as a new species. This study identifies a novel Rickettsiella causing infection in emperor scorpions and characterizes the unique pathological findings of this disease. We suggest this organism be provisionally named Rickettsiella scorpionisepticum.

Phenethyl Isothiocyanate (PEITC) Regulates Autophagy in Chronic Lymphocytic Leukemia.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2906-2906
Author(s):  
Jemimah Adams ◽  
R Gitendra Wickremasinghe ◽  
Archibald G Prentice ◽  
Jonathan C. Strefford ◽  
Andrew Duncombe ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annexin V ◽  
Lymphocytic Leukemia ◽  
Phenethyl Isothiocyanate ◽  
Autophagosome Formation ◽  
Double Membrane ◽  
Transmission Electron ◽  
Membrane Bound ◽  
Autophagy Pathway

Abstract Abstract 2906 Chronic Lymphocytic leukemia (CLL) is currently incurable using conventional therapies. CLL cells can evade killing by various therapeutic strategies. However the precise mechanisms are currently unknown. Autophagy is regulated by a complex system of proteins, and is used by both normal and malignant cells as a protective mechanism against cellular stress induced by starvation, hypoxia, reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress. In malignant cells autophagy was shown to promote tumorigenesis and/or resistance to chemotherapy. Therefore we hypothesized that autophagy may play a role in CLL biology. Autophagy can also promote cell death when stress signals are elevated above a particular threshold for a prolonged period of time. In this study we investigated the basal expression levels of autophagy specific genes and the effect of autophagy specific inhibitors (Bafilomycin, 3-methyladenine and hydroxychloroquine) and inducers (Phenethyl isothiocyanate) on CLL survival. Phenethyl isothiocyanate (PEITC) is about to enter clinical trials for CLL (NCT00968461). We have investigated induction of components of the autophagic pathway following treatment of CLL cells in vitro with a range of chemical inhibitors. Immunoblotting was carried out to investigate components of the autophagy pathway using phosphorylation state-specific and pan-reactive antibodies. Bafilomycin (BAF), 3-methyladenine (3-MA) and hydroxychloroquine (HCQ) toxicity towards CLL samples were evaluated by Annexin V/PI staining, MTT assay and immunoblotting for cleavage of the caspase 3 substrate poly(ADP ribose) polymerase (PARP) from its 116KDa to its 85KDa form. PEITC was used at concentrations between 2.5 and 25μM to investigate its effect on signaling. Autophagy was quantitated by immunoblotting of LC3-I and LC3-II. Lipidation of LC3 from LC3-I to LC3-II is a surrogate marker of autophagy and is essential for autophagasome formation. Immunoblotting was also performed for ATG3, ATG5 and ATG7, key components of the autophagy pathway. Monodansylcadaverine (MDC) was used with immunofluorescence and FACS analysis to investigate increases in autophagasome formation. Transmission electron microscopy (TEM) was used to confirm double membrane bound autophagosomes. Co-immunoprecipitation was used to evaluate if Beclin-1 was sequestered by Bcl-2 preventing autophagy. Its release from Bcl-2 enables Beclin-1 to interact with other autophagy specific proteins and initiates autophagasome formation. LC3-I was lipidated to LC3-II (p=0.019) and ATG3 (p=0.021) was upregulated to a greater extent in CLL samples compared with normal B-cell controls at basal levels. This suggested that autophagy was active to a greater extent in CLL samples compared with normal individuals. In addition Beclin was dissociated from Bcl-2 in CLL samples indicating that autophagy was active. Autophagy appears to be a pro-survival mechanism in untreated CLL cells as inhibiting basal levels of autophagy with autophagy inhibitors BAF (50–200nM), 3-MA (5–10mM) and hydroxychlorquine (5–10μM) resulted in CLL apoptosis as shown by MTT, Annexin V/PI analysis and PARP cleavage. Interestingly augmenting autophagy was also capable of inducing apoptosis in CLL samples. Treatment with PEITC caused an increase in punctate staining using MDC which is suggestive of autophagosome formation. We went on to determine that PEITC further induced LC3-II lipidation using immunoblotting and showed a substantial increase in overall LC3 protein expression. PEITC also induced the expression of ATG3, a key protein in the autophagy pathway. We then evaluated autophagosome formation using TEM (Figure 1). Our data showed greater numbers of autophagosomes in the PEITC treated samples compared to the untreated controls. Therefore autophagy in CLL sits on a knife-edge, such that perturbations that either increase pro- death or decrease pro-survival autophagy signals can result in CLL cell death, depending on the duration and intensity of the signal. Figure 1. Transmission electron microscopy of CLL cells CLL cells were treated with 10μM PEITC. Double membrane bound organelles were found in the CLL cells after treatment which were not present in the no addition control (depicted by the arrows). These organelles are autophagsomes. Magnification (left picture) ruler is 500nM, (right picture) ruler is 100nM Figure 1. Transmission electron microscopy of CLL cells . / CLL cells were treated with 10μM PEITC. Double membrane bound organelles were found in the CLL cells after treatment which were not present in the no addition control (depicted by the arrows). These organelles are autophagsomes. Magnification (left picture) ruler is 500nM, (right picture) ruler is 100nM Disclosures: No relevant conflicts of interest to declare.

scholarly journals Ovary Structure and Oogenesis of Trypophloeus klimeschi (Coleoptera: Curculionidae: Scolytinae)

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1099
Author(s):  
Jing Gao ◽  
Jiaxing Wang ◽  
Hui Chen
Keyword(s):  
Electron Microscopy ◽  
Reproductive System ◽  
Secretory Cells ◽  
Female Reproductive System ◽  
Transition Stage ◽  
Accessory Glands ◽  
Transmission Electron ◽  
Secondary Stage ◽  
Terminal Filament ◽  
Structure And Ultrastructure

The female reproductive system, ovary structure and ultrastructure of Trypophloeus klimeschi (Coleoptera: Curculionidae: Scolytinae) were investigated using light microscopy, scanning electron microscopy, and transmission electron microscopy. Its female reproductive system is comprised of two ovaries (each ovary has two ovarioles), lateral oviducts, common oviduct, spermathecal sac, spermathecal pump, two accessory glands and bursa copulatrix. Well-developed endoplasmic reticulum can be clearly seen in the secretory cells of spermathecal sac. This species has telotrophic meroistic ovarioles that are comprised of terminal filament, tropharium, vitellarium and pedicel. The terminal filaments are simple; each is comprised of cellular peritoneal sheath. The presence of several clusters of nurse cells in the tropharium is indicative that its ovarioles conform to the transition stage. This indicates that there are at least two different types (transition stage and secondary stage) of ovarioles in Curculionidae.

Scanning and Transmission Electron Microscopy of Isolated Cells from the Avian Salt Gland

1977 ◽  
Vol 35 ◽  
pp. 488-489
Author(s):  
Ian G. Thompson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Physiological Stress ◽  
Single Cells ◽  
Salt Gland ◽  
Secretory Cells ◽  
Surface Coat ◽  
Isolated Cells ◽  
Structural Differentiation ◽  
Transmission Electron

With the advent of new techniques for isolating single cells for biochemical and physiological investigation, an important consideration is the morphological integrity of these cells after dissociation from the intact tissue. Do isolated cells retain the degree of structural differentiation that is apparent in vivo? The principal secretory cells of the avian salt gland are an example of cells that are highly differentiated in form under conditions of physiological stress. This report describes the ultrastructure of dissociated salt gland cells as visualized with the scanning and transmission electron microscope.The dissociation procedure employed here was the same as that applied to the exocrine pancreas. For transmission electron microscopy the cell suspension was centrifuged and the resultant pellet prefixed in cacodylate buffered 3% glutaraldehyde- 1% paraformaldehyde, postfixed in unbuffered 1% osmium tetroxide, and embedded in epon-araldite. An assessment of the cell surface coat following enzymatic dissociation was facilitated by the inclusion of ruthenium red (500 ppm) in both the aldehyde and osmium fixation steps.

Characterization of mammary cells from the lactating rat by electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 560-561
Author(s):  
P. Sadhukhan ◽  
J. Chakraborty ◽  
M. S. Soloff ◽  
M. H. Wieder ◽  
D. Senitzer
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Types ◽  
Myoepithelial Cells ◽  
Mammary Tissue ◽  
Secretory Cells ◽  
Isolated Cells ◽  
Transmission Electron ◽  
Cell Processes ◽  
Phosphatase Cytochemistry

The means to identify cells isolated from the mammary gland of the lactating rat as a prerequisite for cell purification have been developed.The cells were isolated from mammary tissue with 0. 1% collagenase, and they were visualized by scanning and transmission electron microscopy and by alkaline phosphatase cytochemistry.The milk-secreting cells have surface microvilli, whereas the surface of the myoepithelial cells is smooth (Fig. 1). The two isolated epithelial cell types are readily distinguishable by transmission electron microscopy (Fig. 2). The secretory cells contain vacuoles and a relatively extensive rough endoplasmic reticulum, whereas the myoepithelial cells contain a more osmiophilic cytoplasm, contractile filaments (Fig. 3) and elongate processes. These features are consistent with the appearance of the two cell types in situ.Incubation of isolated cells with oxytocin prior to glutaraldehyde fixation resulted in the contraction of the myoepithelial cell processes (Figs. 4 & 5). This physiological response to oxytocin shows that the isolated myoepithelial cells were intact. The appearance of isolated secretory cells was unchanged by the presence of oxytocin.

The ultrastructure of the skeleton and skeletogenic tissues of the temperate coral Caryophyllia smithii

1990 ◽  
Vol 70 (2) ◽  
pp. 295-310 ◽  
Author(s):  
Martin D'A.A. Le Tissier
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Organic Matrix ◽  
Secretory Vesicles ◽  
Intercellular Spaces ◽  
Transmission Electron ◽  
Temperate Coral ◽  
Zooxanthellate Coral ◽  
Membrane Bound ◽  
Calicoblastic Ectoderm

The skeleton and calicoblastic ectoderm of the scleractinian non-zooxanthellate coral Caryophyllia smithii were investigated by light microscopy, scanning and transmission electron microscopy. Except for some costal spines, the skeleton was fasciculate. Fasciculi were made up of bundles of crystalline needles, each crystalline needle consisting of a number of linear series of small (<1 μm) rounded crystals. Fractured skeletons showed the fasciculi to be arranged into layers and that within some septa, theca and costal spines there were spaces that contained neither mineral nor organic matter. These spaces could also be found at the growing edges of septa and theca. Demineralization of the skeleton revealed an organic matrix whose configuration mirrored the architecture of the skeleton. In areas of the skeleton where deposition was occurring the overlying calicoblastic ectoderm was relatively thin with prominent intercellular spaces and secretory vesicles. In contrast, over non-depositing areas the calicoblastic ectoderm was thick and contained residual bodies, nematocysts and membrane-bound granules. The results are compared and contrasted with those from scleractinian corals that have endosymbiotic zooxanthellae.

scholarly journals FRTL-5 Rat Thyroid Cells Release Thyroglobulin Sequestered in Exosomes: A Possible Novel Mechanism for Thyroglobulin Processing in the Thyroid

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Pavel Vlasov ◽  
Sonia Q. Doi ◽  
Donald F. Sellitti
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Western Blotting ◽  
Thyroid Stimulating Hormone ◽  
Cellular Proteins ◽  
Thyroid Cells ◽  
Normal Thyroid ◽  
Transmission Electron ◽  
Membrane Bound ◽  
Rat Thyroid

Exosomes are 30–100 nm, membrane-bound vesicles containing specific cellular proteins, mRNAs, and microRNAs that take part in intercellular communication between cells. A possible role for exosomes in thyroid function has not been fully explored. In the present study, FRTL-5 rat thyroid cells were grown to confluence and received medium containing either thyroid stimulating hormone (TSH), exogenous bovine thyroglobulin (bTg), or neither additive for 24 or 48 hours followed by collection of spent medium and ultracentrifugation to isolate small vesicles. Transmission electron microscopy and Western blotting for CD9 indicated the presence of exosomes. Western blotting of exosome extract using a monoclonal anti-Tg antibody revealed a Tg-positive band at ~330 kDa (the expected size of monomeric Tg) with a higher density in TSH-treated cells compared to that in untreated cells. These results are the first to show that normal thyroid cells in culture produce exosomes containing undegraded Tg.

Quantitative high-resolution transmission electron microscopy nanostructure analysis of soot oxidized in diesel spray flame periphery

2020 ◽  
pp. 146808742091448
Author(s):  
Tetsuya Aizawa ◽  
Yoshiaki Toyama ◽  
Ryosuke Kusakari
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Inner Core ◽  
Outer Shell ◽  
Diesel Spray ◽  
Oh Radicals ◽  
Engine Exhaust ◽  
Spray Flame ◽  
Transmission Electron ◽  
Primary Particles

In order to better understand the in-flame diesel soot oxidation processes, soot particles at the oxidation-dominant periphery of diesel spray flame were sampled via newly developed suck type soot sampler employing a high-speed solenoid valve, and their morphology and nanostructure were observed and analyzed via high-resolution transmission electron microscopy. A single-shot diesel flame for the soot sampling experiment was achieved in a constant-volume vessel under a diesel-like condition (9.5 kg/m3, 2.5 MPa, 1070 K, and 21%O2). Morphology of soot aggregates, inner-core/outer-shell structure of primary particles within the aggregates, and carbon crystallite nanostructures within the primary particles were compared between the soot aggregates sampled at the diesel flame core near the central axis and the oxidation-dominant flame periphery. The morphology observation and the inner-core/outer-shell structure characteristics obtained by newly employed concentricity analysis showed that the flame core soot exhibits graphitic primary particles with clear outlines and boundaries similarly observed for engine exhaust soot. Each primary particle contained a well-defined inner core surrounded by thick graphitic outer shell. On the contrary, the flame periphery soot exhibited smaller primary particles with unclear and lumpy outlines containing multiple obscured inner cores surrounded by thinner outer shell. The analysis of carbon crystallite nanostructures within the primary particles showed that the in-flame soot nanostructure shifts toward amorphous from the flame core to the periphery. On the contrary, the engine soot nanostructure in the literature shifts toward graphitic from the in-cylinder TDC to the exhaust, exhibiting the opposite trend with the in-flame soot. These results suggest that the engine exhaust soot has not experienced the rapid in-flame oxidation by OH radicals and is therefore considered not to be the remains of incomplete or partial oxidation, but the runaways escaped from the flame core to the exhaust without being attacked by the in-flame OH radicals.

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