Avoidance of encapsulation in the absence of VLP by a braconid parasitoid of Drosophila larvae: an ultrastructural study

1996 ◽  
Vol 74 (12) ◽  
pp. 2193-2198 ◽  
Author(s):  
Patrice Eslin ◽  
Philippe Giordanengo ◽  
Yvelise Fourdrain ◽  
Geneviève Prévost
Keyword(s):  
Electron Microscopy ◽  
Fat Body ◽  
Adhesive Properties ◽  
Digestive Tube ◽  
Virus Like Particles ◽  
Larval Stages ◽  
Asobara Tabida ◽  
Larval Host ◽  
Drosophila Larvae ◽  
Host Tissues

The hymenopteran Asobara tabida Nees (Braconidae: Alysiinae) parasitizes the larval stages of Drosophila species. In D. melanogaster, 90% of A. tabida eggs avoid encapsulation and are found embedded within the tissues (digestive tube, fat body, tracheae, etc.) of their larval host. Electron microscopy was used to investigate if the embedment of the parasitic egg within the tissues of its host may prevent encapsulation. Study revealed that the outer layer of the A. tabida egg consists of a fibrous exochorion that exhibits adhesive properties within the tissues of D. melanogaster. Three hours after oviposition, any basement membrane surrounding the host tissues that is in contact with the parasitic egg is stuck to the exochorion. Attachment rapidly increases. Nine hours post oviposition, the A. tabida egg is almost totally surrounded by a sheath of host tissue, with only limited areas of the surface remaining uncovered and exposed to attack by the host hemocytes. It is therefore concluded that the adhesion of A. tabida eggs to the host tissues is likely to contribute to their protection from encapsulation during embryogenesis. Also, electron microscopy reveals that no virus-like particles occur in A. tabida, unlike any other braconid parasitoid studied. The absence of virus-like particles is discussed with regard to the importance of host regulation of the particles in other braconid species.

scholarly journals Parasitic infestation in a female of Micropterna nycterobia McLachlan 1875 (Trichoptera, Limnephilidae) found in Monte Cucco cave ( central Italy)

Zoosymposia ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 165-171
Author(s):  
CARLA CORALLINI ◽  
ORIELLA MARCHETTI
Keyword(s):  
Electron Microscopy ◽  
Fat Body ◽  
Central Italy ◽  
Light And Electron Microscopy ◽  
Parasitic Infestation ◽  
Stages Of Development ◽  
Host Tissues

In this study, parasitosis due to Ophryoglena sp. (Ciliophora, Oligohymenophorea) in a Micropterna nycterobia (Trichoptera, Limnephilidae) female is described. The trichopteran was found on 31 October 2002 in a cave, named "Grotta di Monte Cucco," in Central Italy. The specimen, observed in vivo under the stereomicroscope, showed that its abdomen was packed with the ciliate. This parasite had fed on gonads, muscles and fat body of the host, thus confirming the role of Ophryoglena as a parasitic spayer. Different stages of development of the parasite were also detected. The interaction of the parasite with host tissues was investigated by means of light and electron microscopy.

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

scholarly journals Negative Stain Transmission Electron Microscopy of Viruses and Virus-like Particles

2009 ◽  
Vol 15 (S2) ◽  
pp. 376-377 ◽  
Author(s):  
C Humphrey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Virus Like Particles ◽  
Negative Stain ◽  
Transmission Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

scholarly journals Immunolocalization of NA+,K+-ATPase in the Branchial Cavity During the Early Development of the European Lobster Homarus Gammarus (Crustacea, Decapoda)

2001 ◽  
Vol 49 (8) ◽  
pp. 1013-1023 ◽  
Author(s):  
Jean-Hervé Lignot ◽  
Guy Charmantier
Keyword(s):  
Electron Microscopy ◽  
Immunogold Electron Microscopy ◽  
Α Subunit ◽  
European Lobster ◽  
Homarus Gammarus ◽  
Larval Stages ◽  
Transmission Electron ◽  
Branchial Cavity ◽  
Enzyme Location ◽  
Ion Pumping

We examined the ontogeny of the osmoregulatory sites of the branchial cavity in embryonic and early postembryonic stages of the European lobster Homarus gammarus through transmission electron microscopy, immunofluorescence microscopy, and immunogold electron microscopy using a monoclonal antibody IgGα5 raised against the avian α-subunit of the Na+,K+-ATPase. In mid-late embryos, Na+,K+-ATPase was located along the pleurites and within the epipodite buds. In late embryos just before hatching, the enzyme was confined to the epipodite epithelia. After hatching, slight differentiations of ionocytes occured in the epipodites of larval stages. Na+,K+-ATPase was also located in the ionocytes of the epipodites of larvae exposed to seawater (35.0‰) and to dilute seawater (22.1 ‰). After metamorphosis, the inner-side branchiostegite epithelium appeared as an additional site of enzyme location in postlarvae held in dilute seawater. Within the ionocytes, Na+,K+-ATP-ase was mostly located along the basolateral infoldings. These observations are discussed in relation to the physiological shift from osmoconforming larvae to slightly hyper-regulating (in dilute seawater) postmetamorphic stages. The acquisition of the ability to hyper-osmo-regulate probably originates from the differentiation, on the epipodites and mainly along the branchiostegites, of ionocytes that are the site of ion pumping as evidenced by the location of Na+,K+-ATPase. (J Histochem Cytochem 49:1013–1023, 2001)

Eimeria species which infect the chicken contain virus-like RNA molecules

Parasitology ◽  
1990 ◽  
Vol 101 (2) ◽  
pp. 163-169 ◽  
Author(s):  
J. Ellis ◽  
H. Revets
Keyword(s):  
Electron Microscopy ◽  
Eimeria Species ◽  
Subcellular Fractionation ◽  
Rnase A ◽  
Virus Like Particles ◽  
Rna Molecules

There is increasing support for the presence of viruses and virus-like particles inside protozoan cells. This study describes viral-like RNA molecules that have been detected in two species of Eimeria that infect the chicken. The RNA molecule identified in E. maxima has been characterized: subcellular fractionation studies have shown that the RNA is present in the cytoplasm, probably as an abundant ribonucleoprotein that is insensitive to RNAse A treatment. Electron microscopy has demonstrated that this RNA molecule is double stranded. In addition, all E. maxima strains examined so far contain this RNA molecule.

scholarly journals Virus-Like Particles and Cytopathic Activity in Urine of Patients with Leukemia

Blood ◽  
1966 ◽  
Vol 28 (3) ◽  
pp. 465-478 ◽  
Author(s):  
RICHARD P. AMES ◽  
JOSEPH T. SOBOTA ◽  
REGINALD L. REAGAN ◽  
MYRON KARON
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Acute Leukemia ◽  
Vitro Assay ◽  
Chronic Granulocytic Leukemia ◽  
Virus Like Particles ◽  
Cytopathic Effects ◽  
Culture Activity ◽  
Granulocytic Leukemia

Abstract Urine pellet material of patients with leukemia was examined by electron microscopy in an effort to find more convenient sources of virus material for tissue culture and animal infectivity studies. Thirty urine specimens from 16 patients with acute leukemia, 2 patients with chronic granulocytic leukemia and 1 patient with Burkitt’s lymphoma, and 17 urine samples from 15 control patients were examined. Virus-like particles were observed in 7 of the 16 patients with acute leukemia, 1 of the 2 patients with chronic granulocytic leukemia, and 1 of the 15 controls. Although these particles showed slight morphologic differences, many were similar in ultrastructure and in density gradient characteristics to the virus particles observed in murine leukemia and to the particles seen by other workers in plasma and tissues of patients with leukemia and lymphoma. Cytopathic effects on WI-38 fibroblasts were observed in urine from 3 patients with leukemia. These effects resembled cytomegalovirus infection, but confirmatory tests were not carried out. Whether the virus-like particles demonstrated by electron microscopy in this study are responsible for the cytopathic effects is at present uncertain. The correlation of a morphologic structure with tissue culture activity cannot be answered until suitable in vitro assay and transformation systems are developed to purify and test these particles. This study suggests that urine may serve as a convenient source for the study and development of such test systems using the electron microscope to correlate structure with biologic activity.

scholarly journals Genetic Screen in Drosophila Larvae Links ird1 Function to Toll Signaling in the Fat Body and Hemocyte Motility

PLoS ONE ◽  
2016 ◽  
Vol 11 (7) ◽  
pp. e0159473 ◽  
Author(s):  
Martin R. Schmid ◽  
Ines Anderl ◽  
Hoa T. M. Vo ◽  
Susanna Valanne ◽  
Hairu Yang ◽  
...  
Keyword(s):  
Fat Body ◽  
Genetic Screen ◽  
Toll Signaling ◽  
Drosophila Larvae

Olfactory Microhabitat Selection in Leptopilina Heterotoma (Thomson) (Hym.: Eucoilidae), a Parasitoid of Drosophilidae

1984 ◽  
Vol 35 (3) ◽  
pp. 497-504 ◽  
Author(s):  
Louise E.M. Vet ◽  
Karin Van Opzeeland
Keyword(s):  
Foraging Efficiency ◽  
Microhabitat Selection ◽  
Behavioural Flexibility ◽  
Ecological Significance ◽  
Parasitoid Species ◽  
Temporal Separation ◽  
Leptopilina Heterotoma ◽  
Asobara Tabida ◽  
Drosophila Larvae ◽  
Larval Conditioning

Leptopilina heterotoma (Thomson) and Asobara tabida (Nees), solitary endoparasitoids of frugivorous Drosophila larvae, are assumed to be competitors. Olfactometer experiments showed, however, that the species differ in their preference for microhabitat odours. Whereas A. tabida prefers a fresh fermenting sugar/yeast medium, L. heterotoma prefers this medium in a later stage of decay. These results are confirmed by field observations. This temporal separation between the species, which is not complete because some multiparasitism does occur, may be one of the factors to their coexistence. Odour preference in L. heterotoma is not modified by larval conditioning, but conditioning of the adults significantly influenced their odour response. The ecological significance of such learning is discussed. It is argued that even though such behavioural flexibility may enhance foraging efficiency when resources are unpredictable, it may also influence the amount of competition between the two parasitoid species.

scholarly journals Electron Microscopy of the Bovine Cutaneous Papilloma

1966 ◽  
Vol 3 (3) ◽  
pp. 196-207 ◽  
Author(s):  
D. Brobst ◽  
E.J. Hinsman
Keyword(s):  
Electron Microscopy ◽  
Plasma Membranes ◽  
Light And Electron Microscopy ◽  
Degenerative Changes ◽  
Virus Like Particles ◽  
Cytoplasmic Vacuolation ◽  
Naturally Occurring ◽  
Prickle Cell ◽  
In Cells

Experimentally produced bovine cutaneous papillomas of 30, 76 and 112 days' duration as well as 3 naturally occurring bovine cutaneous papillomas were examined by light and electron microscopy. Degenerative changes were not observed in the fibromatous base of the 30-day-old papilloma. An alteration in all papillomas older than 30 days was cytoplasmic vacuolation in cells of the prickle cell and keratohyaline layers. As cells progressed upward their degeneration became more prominent. In the keratinized layers of 2 papillomas virus-like particles were observed within plasma membranes of keratinized cells.

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