Salivary secretions from the honeybee mite, Varroa destructor: effects on insect haemocytes and preliminary biochemical characterization

Parasitology ◽  
2011 ◽  
Vol 138 (5) ◽  
pp. 602-608 ◽  
Author(s):  
E. H. RICHARDS ◽  
BENJAMIN JONES ◽  
ALAN BOWMAN
Keyword(s):  
Wound Healing ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Biochemical Characterization ◽  
Electrophoretic Analysis ◽  
Cotton Wool ◽  
Puncture Wound ◽  
Molecular Weights ◽  
Insect Haemocytes

SUMMARYIntroduction. The ectoparasitic honey bee mite Varroa destructor feeds on the haemolymph of the honey bee, Apis mellifera, through a single puncture wound that does not heal but remains open for several days. It was hypothesized that factors in the varroa saliva are responsible for this aberrant wound healing. Methods. An in vitro procedure was developed for collecting salivary gland secretions from V. destructor. Mites were incubated on balls of cotton wool soaked in a tissue culture medium (TC-100), and then induced to spit by topical application of an ethanolic pilocarpine solution. Results. Elution of secretions from balls of cotton wool, followed by electrophoretic analysis by SDS-PAGE and electroblotting indicated the presence of at least 15 distinct protein bands, with molecular weights ranging from 130 kDa to <17 kDa. Serial titration of V. destructor salivary secretions in TC-100 followed by an 18-h incubation with haemocytes from the caterpillar, Lacanobia oleracea, indicated that the secretions damage the haemocytes and suppresses their ability to extend pseudopods and form aggregates. Conclusion. We suggest that these secretions facilitate the ability of V. destructor to feed repeatedly off their bee hosts by suppressing haemocyte-mediated wound healing and plugging responses in the host.

scholarly journals In Vitro Evaluation of Acute Toxicity of Five Citrus spp. Essential Oils towards the Parasitic Mite Varroa destructor

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1182
Author(s):  
Roberto Bava ◽  
Fabio Castagna ◽  
Cristian Piras ◽  
Ernesto Palma ◽  
Giuseppe Cringoli ◽  
...  
Keyword(s):  
Essential Oils ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Negative Impact ◽  
Positive Control ◽  
Citrus Limon ◽  
Citrus Paradisi ◽  
Bee Health ◽  
Citrus Spp

Varroa destructor is the most important ectoparasitic mite of honey bees that has a negative impact on bee health and honey production. The control programs are mainly based on the use of synthetic acaricides that are often administered indiscriminately. All this has led to drug resistance that now represent a great concern for honey bee farming. The research for alternative products/methods for mites’ control is now mandatory. The aim of this study was to test whether Citrus spp. essential oils could diminish the growth of the V. destructor mite. In Calabria (southern Italy), plants of the Citrus genus are very common and grow both spontaneously and cultured. The essential oils used in this study were extracted from bergamot (Citrus bergamia), grapefruit (Citrus paradisi), lemon (Citrus limon), orange (Citrus sinensis), and mandarin (Citrus reticulata) by hydrodistillation. Every EO was in vitro tested against V. destructor. Each experimental replicate was performed using 35 viable adult female mites (5 for each EO) collected the same day from the same apiary and included negative controls (5 individuals exposed to acetone only) and positive controls (5 individuals exposed to Amitraz diluted in acetone). The essential oils (Eos) were diluted (0.5 mg/mL, 1 mg/mL, and 2 mg/mL) in HPLC grade acetone to obtain the working solution to be tested (50 µL/tube). Mite mortality was manually assessed after 1 h exposure under controlled conditions. The essential oils that showed the best effectiveness at 0.5 mg/mL were bergamot, which neutralized (dead + inactivated) 80% (p ≤ 0.001) of the parasites; grapefruit, which neutralized 70% (p ≤ 0.001); and lemon, which neutralized 69% of them. Interestingly, the positive control (Amitraz) at the same concentration neutralized 60% of the parasites. These results demonstrate that Calabrian bergamot, grapefruit, and lemon Eos consistently reduced V. destructor viability and open the possibility for their utilization to control this parasite in honey bee farming.

scholarly journals Double isotype production by a neoplastic B cell line. I. Cellular and biochemical characterization of a variant of BCL1 that expresses and secretes both IgM and IgG1.

1986 ◽  
Vol 164 (2) ◽  
pp. 548-561 ◽  
Author(s):  
Y W Chen ◽  
C J Word ◽  
S Jones ◽  
J W Uhr ◽  
P W Tucker ◽  
...  
Keyword(s):  
B Cell ◽  
Biochemical Characterization ◽  
Fluorescence Analysis ◽  
Heavy Chains ◽  
Molecular Weights ◽  
Antiidiotypic Antibody ◽  
B Cell Leukemia ◽  
The Subject

We have subcloned the in vitro-adapted murine B cell leukemia, BCL1.B1, to obtain a variant that expresses both IgM and IgG1. By fluorescence analysis, radioiodination, and immunoprecipitation of cell surface Ig, and by RIA of medium from limiting dilution cultures, we have shown that: (a) all the cells express and secrete both isotypes. The heavy chains of both IgG1 and IgM have the apparent molecular weights of membrane mu and gamma 1 chains; (b) both isotypes bear the same idiotype as determined by immunoprecipitation with antiidiotypic antibody, and both use the same VDJ rearrangement as shown by Southern blotting; and (c) the cells express the membrane and secreted forms of mRNA for both mu and gamma 1 but not gamma 2b or gamma 3. Taken together, the data suggest that all the cells are synthesizing, expressing on their surface, and secreting two isotypes that use the same VDJ rearrangement in the DNA and express the same serologically-defined idiotype. The molecular basis responsible for the production of the two isotypes in a single cell is the subject of the accompanying paper.

In vitro antibacterial and antiparasitic effect of citrus fruit essential oils on the honey bee pathogen Paenibacillus larvae and the parasitic mite Varroa destructor

2009 ◽  
Vol 48 (1) ◽  
pp. 77-78 ◽  
Author(s):  
Sandra Rosa Fuselli ◽  
Matías Maggi ◽  
Susana Beatriz García de la Rosa ◽  
Judith Principal ◽  
Martín Javier Eguaras ◽  
...  
Keyword(s):  
Essential Oils ◽  
Honey Bee ◽  
Varroa Destructor ◽  
Citrus Fruit ◽  
Paenibacillus Larvae ◽  
Parasitic Mite

Fine structural and biochemical characterization of phloem proteins

1980 ◽  
Vol 58 (7) ◽  
pp. 802-806 ◽  
Author(s):  
Rainer Kollmann
Keyword(s):  
Molecular Weight ◽  
Conformational Changes ◽  
Biochemical Characterization ◽  
Protein Pattern ◽  
Molecular Weights ◽  
P Protein ◽  
Sieve Tubes ◽  
Species Specific

The heterogeneous group of proteins occurring in the exudate of cut phloem tissue will be termed phloem proteins. Their molecular weights range from less than 30 000 to over 100 000. The protein pattern is a species-specific constant. Depending on the plant species the bulk of phloem proteins is either basic or acidic. In Cucurbita maxima up to 40% of the total phloem proteins are basic proteins with a molecular weight of 116 000; it shows G–F transition properties in vitro and represents the so-called P-protein in the sieve tubes of angiosperms. Depending on the stage of cell differentiation the P-protein shows various conformational changes in situ: amorphous, filamentous tubular, and paracrystalline structures are described. P-protein differs from actin- or tubulinlike proteins with regard to their molecular weight and most biochemical characteristics. The main discrepancy is the failure to bind either heavy meromyosin or any nucleotides and colchicine. No structural evidence exists for cytoplasmic streaming in mature sieve tubes based on an actin–myosin system. The function of P-protein is still questionable; sieve pore plugging after wounding, sites of enzymatic activity, and surface interaction are discussed.

scholarly journals A novel system for maintaining Varroa destructor mites on artificial diets and its application for studying mites as a vector for honey bee viruses

2019 ◽  
Author(s):  
Francisco Posada-Florez ◽  
Eugene V. Ryabov ◽  
Matthew C. Heerman ◽  
Yanping Chen ◽  
Jay D. Evans ◽  
...  
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Artificial Diet ◽  
Artificial Diets ◽  
Deformed Wing Virus ◽  
Limited Success ◽  
Honey Bee Health ◽  
Serious Injury ◽  
Bee Viruses

AbstractThe mite Varroa destructor is one of the most destructive parasites of the honey bee (Apis mellifera) and the primary cause of colony collapse in most regions of the world. These mites cause serious injury to their hosts, especially during the larval and pupal stages, and serve as the vector for several viruses, which affect honey bee health causing colony death. Attempts by beekeepers to control these mites have yielded limited success. The inability to rear populations of mites in vitro that excludes contact with their honey bee hosts has stymied research of Varroa biology. Previous attempts to rear and/or maintain Varroa mites in vitro by feeding them on artificial diets have had limited success. Several methods were plagued by mechanical failures including leaking membranes and, thus far, none have been widely adopted. Here we report a robust system for maintaining Varroa mites that includes an artificial diet, which does not contain honey bee tissue-derived components, thus making it particularly valuable in studying mite vectoring of honey bee viruses. With our system we demonstrated for the first time that Varroa mites maintained on an artificial diet supplemented with the particles of honey bee viruses, cDNA clone-derived genetically tagged Varroa destructor virus-1 and wild-type Deformed wing virus, can acquire and later transmit these viruses to recipient honey bee pupae. Along with providing an opportunity to study parasites and pathogens in the absence of honey bee hosts, this in vitro system for Varroa mite maintenance is both scalable and consistent. These features can be used to better understand mite nutritional needs, metabolic activity, responses to chemicals and other biological functions.

scholarly journals Varroa destructor mites vector and transmit pathogenic honey bee viruses acquired from an artificial diet

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242688
Author(s):  
Francisco Posada-Florez ◽  
Eugene V. Ryabov ◽  
Matthew C. Heerman ◽  
Yanping Chen ◽  
Jay D. Evans ◽  
...  
Keyword(s):  
Honey Bee ◽  
Varroa Destructor ◽  
Artificial Diet ◽  
Fat Body ◽  
Deformed Wing Virus ◽  
Virus Particles ◽  
Colony Collapse ◽  
Cellular Components ◽  
Bee Viruses

The ectoparasitic mite Varroa destructor is one of the most destructive pests of the honey bee (Apis mellifera) and the primary biotic cause of colony collapse in many regions of the world. These mites inflict physical injury on their honey bee hosts from feeding on host hemolymph and fat body cells/cellular components, and serve as the vector for deadly honey bee viruses, including Deformed wing virus (DWV) and the related Varroa destructor virus-1 (VDV-1) (i.e., DWV-like viruses). Studies focused on elucidating the dynamics of Varroa-mediated vectoring and transmission of DWV-like viruses may be confounded by viruses present in ingested host tissues or the mites themselves. Here we describe a system that includes an artificial diet free of insect tissue-derived components for maintaining Varroa mites for in vitro experimentation. Using this system, together with the novel engineered cDNA clone-derived genetically tagged VDV-1 and wild-type DWV, we demonstrated for the first time that Varroa mites provided an artificial diet supplemented with engineered viruses for 36 hours could acquire and transmit sufficient numbers of virus particles to establish an infection in virus-naïve hosts. While the in vitro system described herein provides for only up to five days of mite survival, precluding study of the long-term impacts of viruses on mite health, the system allows for extensive insights into the dynamics of Varroa-mediated vectoring and transmission of honey bee viruses.

scholarly journals Biological and physicochemical properties of cymbidium mosaic virus

2020 ◽  
pp. 71-76
Author(s):  
N.I. Parkhomenko ◽  
◽  
L.A. Maksymenko ◽  
L.F. Didenko ◽  
◽  
...  
Keyword(s):  
Molecular Weight ◽  
Mosaic Virus ◽  
Sedimentation Coefficient ◽  
Electrophoretic Analysis ◽  
Translation System ◽  
Cymbidium Mosaic Virus ◽  
Molecular Weights ◽  
Viral Particles ◽  
Viral Preparation

The isolated cymbidium mosaic virus (CMV) is one of the most wide-spread and dangerous pathogens that infects promising varieties of orchids. It causes characteristic symptoms on orchid plants, which are manifested in the form of a mosaic. Over time, these areas are necrotized, leading to the stop of flowering the plants and reducing their decorative value. The CyMV is not spread by insects-carriers, but is transmitted by the mechanical inoculation with juice. Electron microscopy revealed flexible filamentous viral particles with a length of about 500 nm. The purified viral preparation is sedimented with a single peak with a sedimentation coefficient of 142S. The floating density of the virus in the preformed CsCl gradient corresponded to 1.3 g/cm3. The electrophoretic analysis of proteins in polyacrylamide gel under denatured conditions showed the presence of two polypeptides with molecular weights of 27 and 31 kDa. RNA CyMV has a molecular weight of 2 · 106 Da. In the translation system of rabbit reticulocytes in vitro, a protein with a molecular weight of about 27 kDa is synthesized. The obtained data allow us to refer CyMV to the group of potexviruses.

The in vivo distribution and dynamics of DNA topoisomerase II in Drosophila embryonic nuclei and chromosomes

1993 ◽  
Vol 51 ◽  
pp. 74-75
Author(s):  
Jason R. Swedlow ◽  
Neil Osheroff ◽  
Tim Karr ◽  
John W. Sedat ◽  
David A. Agard
Keyword(s):  
Topoisomerase Ii ◽  
Biochemical Characterization ◽  
Developmental Cycle ◽  
Dna Topoisomerase Ii ◽  
Chromosomal Distribution ◽  
Dna Topoisomerase ◽  
Ideal System ◽  
Dnase Treatment

DNA topoisomerase II is an ATP-dependent double-stranded DNA strand-passing enzyme that is necessary for full condensation of chromosomes and for complete segregation of sister chromatids at mitosis in vivo and in vitro. Biochemical characterization of chromosomes or nuclei after extraction with high-salt or detergents and DNAse treatment showed that topoisomerase II was a major component of this remnant, termed the chromosome scaffold. The scaffold has been hypothesized to be the structural backbone of the chromosome, so the localization of topoisomerase II to die scaffold suggested that the enzyme might play a structural role in the chromosome. However, topoisomerase II has not been studied in nuclei or chromosomes in vivo. We have monitored the chromosomal distribution of topoisomerase II in vivo during mitosis in the Drosophila embryo. This embryo forms a multi-nucleated syncytial blastoderm early in its developmental cycle. During this time, the embryonic nuclei synchronously progress through 13 mitotic cycles, so this is an ideal system to follow nuclear and chromosomal dynamics.

An in vitro model for investigation of vitamin A effects on wound healing

2021 ◽  
pp. 1-6
Author(s):  
Hoda Keshmiri Neghab ◽  
Mohammad Hasan Soheilifar ◽  
Gholamreza Esmaeeli Djavid
Keyword(s):  
Wound Healing ◽  
Endothelial Cell ◽  
Vitamin A ◽  
In Vitro Model ◽  
Cellular Proliferation ◽  
Endothelial Cell Migration ◽  
Normal Fibroblast ◽  
Anti Inflammatory ◽  
Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inflammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inflammation responses.

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