Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “WASPS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed2002

Pharmacology and chemistry of the venoms of solitary wasps.

In this study certain activities of solitary wasp venoms collected from the Suez Canal area (Bembix oculata, Dielis collaris, and Scolia erythrocephala) were investigated. The effects of these venoms on different types of muscles were studied, and in addition, the chemical structures were studied by electrophoretic analysis. We found that the venoms affect different types of muscles (cardiac, skeletal, and smooth) in different ways. The effect of the venoms on heart muscle was rapid and led to bradycardia, an increase in R amplitude on ECG, and other cardiac disorders such as atrioventricular block. These effects were abolished by atropine, indicating they were mediated through the peripheral nervous system. All of the venoms we tested reversibly blocked the nicotinic receptors of toad skeletal muscle and the muscarinic receptors of smooth muscles. Through electrophoretic analysis, seven bands were detected in Dielis collaris venom, while five bands were detected in Bembix oculata venom.

Animals↗
PubMed2000

Mushroom bodies of vespid wasps.

Mushroom bodies are higher centers in the brains of insects. Studies on honey bees and species of ants suggest that these centers are particularly prominent in social insects. The present study confirms the presence of large mushroom bodies in five subfamilies of vespid wasps, while at the same time showing significant departures from the mushroom body organization that typifies bees and ants. Although the basic organizational plan of the insect mushroom body into calyces, peduncle, and lobes is maintained, as is the arrangement of axons of intrinsic neurons, the size and arrangements of the vespid mushroom body lobes differ markedly from those known from other Hymenoptera. Furthermore, considerable variation is found both between and within vespid subfamilies. The present results are discussed with respect to current hypotheses about functional attributes of mushroom bodies and the phylogeny of the Vespidae.

Animals↗
PubMedDate not supplied

Sensilla on the antenna and ovipositor of the parasitic wasps trichogramma galloi Zucchi and T. pretiosum Riley (Hym., Trichogrammatidae).

The understanding of the stimuli perceived by these parasitoids to accept and exploit a potential host may support the development of artificial hosts for their in vitro rearing. The most common structures involved in the host selection process in parasitoids are the antenna and the ovipositor. Sensilla present on these structures are involved in host recognition and acceptance, and the identification of which kind of stimulus (physical or chemical) is perceived by the sensilla could provide data about the host characteristics that elicit the parasitism behavior. The antenna and ovipositor of the wasps Trichogramma galloi and T. pretiosum were studied to identify their sensillar structure and their possible functions in the host selection process, as a support to the development of an artificial host for the in vitro rearing of these parasitoids. Seven sensilla and one setiform structure were present on the antenna of both parasitoid species, with a mixed, chemo-, or mechanoreception function. The ovipositor has four different sensilla and their role in the host evaluation is suggested.

Animals↗
PubMed1996

Pertussis toxin-insensitive effects of mastoparan, a wasp venom peptide, in PC12 cells.

Recent studies have shown that mastoparan, an amphiphilic peptide derived from wasp venom, modifies the secretion of neurotransmitters and hormones from a variety of cell types. Mastoparan interacts with heterotrimeric guanine nucleotide-binding proteins (G proteins) such as Gi and G(o), which are ADP-ribosylated by pertussis toxin (PTX) and thereby uncoupled from receptors. Previously, some of the effects of mastoparan including secretion were reported to be modified selectively by PTX but not by cholera toxin (CTX). In the present study, we examined the influence of bacterial toxins on the effects of mastoparan in PC12 cells. Mastoparan stimulated [3H]noradrenaline (NA) release from prelabeled PC12 cells in the absence of CaCl2, although high K+ or ATP-stimulated the release in a Ca(2+)-dependent manner. Pretreatment with CTX, not PTX, for 24 h inhibited mastoparan-stimulated [3H]NA release. Mastoparan inhibited forskolin-stimulated cyclic AMP accumulation in a dose-dependent manner, although mastoparan had no effect by itself. Pretreatment with PTX completely abolished the inhibitory effect of carbachol via Gi on cyclic AMP accumulation and partially reduced the effect of mastoparan. However, the inhibitory effect of 20 microM mastoparan was not modified by pretreatment with PTX. Thus, we investigated the effect of mastoparan on CTX-catalyzed [32P]ADP-ribosylation of proteins in PC12 cells. A subunit of CTX (CTX-A) catalyzed [32P]ADP-ribosylation of many proteins in the cytosolic fraction of PC12 cells. One of these was a 20 kDa protein, named ADP-ribosylating factor (ARF). The addition of mastoparan to assay mixtures inhibited ADP-ribosylation of many proteins including ARF and CTX-A in the presence of the cytosolic fraction. In the absence of the cytosolic fraction, however, mastoparan slightly enhanced ADP-ribosylation of bovine serum albumin and auto-ADP-ribosylation by CTX-A. Mastoparan did not inhibit ADP-ribosylation of the alpha subunit of Gs in the membrane fraction. These findings suggest that 1) mastoparan interacts with PTX-insensitive and CTX-sensitive factor(s) to stimulate NA release, and 2) mastoparan interacts with ARF inhibiting its activity to enhance the ADP-ribosylation reaction by CTX. ARF may be an exocytosis-linked G protein.

ADP-Ribosylation Factors↗
PubMed2000

Solid phase synthesis and biological evaluation of enantiomerically pure wasp toxin analogues PhTX-343 and PhTX-12.

PhTX-343 and PhTX-12, analogues of the natural polyamine wasp toxin PhTX-433, were synthesised in 40-60% yields as pure enantiomers using solid phase synthesis techniques. Capillary electrophoresis procedures were developed for chiral separation and determination of enantiomeric purity (ee) of the enantiomers of PhTX-343 and PhTX-12. The methods were optimised with respect to chiral selector, buffer pH, and temperature around the capillary. Thus, rac-PhTX-343 was resolved using a separation buffer containing 30 mM heptakis-(2, 6-di-O-methyl)-beta-cyclodextrin in 50 mM 6-aminocarproic acid (pH 4. 0) at 15 degrees C. rac-PhTX-12 was not resolvable in this system, but could be resolved using a separation buffer containing 10% w/v of dextrin 10, a linear maltodextrin, in 50 mM 6-aminocaproic acid (pH 4.0) at 15 degrees C. Using these methods, the optical purity of the synthetic enantiomers was determined to be ee > 99%. The enantiomers were also characterised by chiroptical methods. The antagonist potency of the enantiomers was tested on nicotinic acetylcholine receptors (human muscle-type nAChR) expressed in TE671 cells, ionotropic glutamate receptors in Xenopus laevis oocytes (expressing recombinant GluR1flop receptors), and locust muscle ionotropic glutamate receptors sensitive to quisqualate (qGluR). The potencies of each pair of enantiomers were similar (eudismic ratio close to 1).

Animals↗
PubMed1999

Parkinsonism after a wasp sting.

A 49-year-old man had mild parkinsonism after being stung by a wasp, a member of the Hymenoptera order. His clinical course was stable for 6 months after which his condition rapidly progressed to a severe akinetic-rigid syndrome with evidence, on a magnetic resonance imaging brain scan, of marked destruction of the basal ganglia. The symptoms did not respond to standard antiparkinsonian medications. Repeated courses of plasmapheresis followed by monthly intravenous infusions of immunoglobulin and long-term administration of azathioprine halted and appeared to partially reverse his deterioration. The literature on the neurologic, particularly the extrapyramidal, manifestations of stings by insects of the Hymenoptera order is reviewed and the possible pathophysiological mechanisms of injury are discussed. Hymenoptera stings should be included in the differential diagnosis of acute and chronic extrapyramidal syndromes.

Animals↗
PubMed2006

Wasps, beetles and the beginning of the ends.

Recent papers investigating the genes regulating early embryogenesis in the wasp Nasonia vitripennis and the beetle Tribolium castaneum have provided us with important clues as to how early development is controlled in insects other than higher dipterans such as Drosophila melanogaster. The results of these studies demonstrate that in insects that do not have bicoid, anterior patterning is regulated by a combination of maternal orthodenticle and hunchback. Furthermore, during the evolution of long-germ-band development, Nasonia and Drosophila may have evolved different mechanisms to pattern posterior segments, marginalising the important role of the terminal system in short-germ-band embryos.

Animals↗
PubMed2001

Antennal multiporous sensilla: their gustatory features for host recognition in female parasitic wasps (insecta, Hymenoptera: Platygastroidea).

In parasitic wasps, various kinds of antennal plates have been interpreted as olfactory organs due to the presence of numerous pores. However, on the basis of ultrastructural investigations, some of these multiporous plates were revealed as being release sites of exocrine glands while others were postulated to have a gustatory function. Such sensilla, present only on female antennae, show unique features, found exclusively in Platygastroidea, with some differences between Scelionidae and Platygastridae. The cuticular apparatus consists of a short basiconic shaft with an apical multiporous area, the pores of which are covered by movable structures. The cellular components are made up of a remarkable number of sensory neurons, from 200 to 220, and an undefined number of sheath cells. These multiporous sensilla have tubular accessory glands that release their secretion through the socket sensillum only in scelionids. These morphological characters, combined with behavioral observations, strongly suggest a gustatory function, although electrophysiological studies are still needed to confirm this. A new terminology for antennal multiporous plates is discussed in relation to their different functions.

Animals↗
PubMed2001

Kinetics of plasma cytokine levels in children hyposensitized with wasp venom.

Specific immunotherapy shifts immune responses towards a Th0/Th1 response. Production of chemokines is also decreased early after the initiation of rush venom immunotherapy. We aimed to investigate in vivo whether cytokine plasma levels reflect the shift towards a Th0-Th1 pattern of immune response as seen in vitro in lymphocytes from patients undergoing venom immunotherapy. Therefore, we studied plasma levels of various cytokines before (day 1), during (day 2), and after (day 4) rush immunotherapy in nine wasp-allergic children. The levels of interleukin-5 and IFN-gamma were below the detection threshold. No variations were observed in levels of interleukin-4, interleukin-10, and TNF-alpha. In contrast, mean levels of RANTES transiently increased at day 2, and decreased below the pretreatment levels at day 4. Those alterations were significant in five children with high levels of RANTES at day 1, and reporting severe anaphylaxis. In the four other children, the levels of RANTES were not significantly increased at day 4. These results suggest that RANTES plasma levels are positively correlated with the severity of the reaction to hymenoptera venom, and that a significant decrease in the levels of RANTES occurs only in children with high pretreatment levels. However, the kinetics of RANTES plasma levels correlated neither with the results of allergological tests, nor with the outcome of venom immunotherapy.

Anaphylaxis↗
PubMed1993

Ecdysteroid induction of embryonic morphogenesis in a parasitic wasp.

Development of the parasitic wasp Copidosoma floridanum (Hymenoptera: Encyrtidae) is unusual in two ways. As many as 3000 embryos are formed from a single egg and embryonic morphogenesis is closely synchronized with the onset of the metamorphosis of its host. Given this extreme synchrony between parasite and host development, we undertook a series of experiments to determine whether host endocrine factors regulate C. floridanum embryonic morphogenesis. Here we report that C. floridanum embryos must develop for 9 days before acquiring the competence to undergo morphogenesis. Furthermore, several pieces of evidence suggest that ecdysteroids of host origin regulate induction of C. floridanum morphogenesis. First, competent embryos initiated morphogenesis when transplanted into host larvae and pupae, host stages possessing elevated ecdysteroid titers, but not when transplanted into adult moths. Second, morphogenesis was arrested by ablation of the host's source of ecdysone, but could be rescued by injection of 20-hydroxyecdysone in a dose-dependent manner. Finally, a segment of DNA encoding a zinc finger nearly identical in sequence to a portion of the ecdysone receptor of Drosophila melanogaster was isolated and characterized from C. floridanum. This putative ecdysone receptor probe indicated that expression of this gene was correlated with the initiation of C. floridanum embryonic morphogenesis. The temporal pattern of putative receptor RNA accumulation increased in association with the onset of morphogenesis, while the spatial pattern of expression was associated with the invagination of cells forming the gastrula. Together, these data suggest that ecdysone of host origin is directly involved in the induction of C. floridanum embryonic morphogenesis.

Amino Acid Sequence↗
PubMed1998

Production of early expressed parasitism-specific proteins in alternate sphingid hosts of the braconid wasp Cotesia congregata.

Parasitism of Manduca sexta larvae by the braconid wasp Cotesia congregata or injection of C. congregata polydnavirus (CcPDV) causes numerous alterations in host physiology, including developmental arrest, abrogation of host immunity, and the production of three abundant early expressed proteins (EP1, EP2, and EP3) that are secreted in large amounts into the host's hemolymph. Here we compare the levels of these proteins present in the hemolymph of three other sphingid species that vary in their compatibility for C. congregata. Hyles lineata was found to be permissive for C. congregata and EP1, EP2, and EP3 were present in larval hemolymph at levels comparable to those found in hemolymph from parasitized M. sexta larvae. By contrast, the lowest levels of EP proteins were found in hemolymph from parasitized Pachysphinx occidentalis larvae and this species was found to be completely refractory, since C. congregata eggs were invariably encapsulated. Parasitism of Sphinx vashti by C. congregata resulted in moderate levels of EP production. While the observed immune response was incomplete and some encapsulation of C. congregata eggs and/or larvae was observed, low numbers of S. vashti nevertheless were able to complete their development and emerge as adults. Thus, a correlation was established between host compatibility and induction of synthesis of the three parasitism-specific proteins, although the linkage between quantitative levels of EP production and the extent of encapsulation was variable.

Animals↗
PubMed2001

Integrative study on chromosome evolution of mammals, ants and wasps based on the minimum interaction theory.

There is well-known evidence that in many eukaryotes, different species have different karyotypes (e.g. n=1-47 in ants and n=3-51 in mammals). Alternative (fusion and fission) hypotheses have been proposed to interpret this chromosomal diversity. Although the former has long been accepted, accumulating molecular genetics evidence seems to support the latter. We investigated this problem from a stochastic viewpoint using the Monte Carlo simulation method under the minimum interaction theory. We found that the results of simulations consistently interpreted the chromosomal diversity observed in mammals, ants and wasps, and concluded that chromosome evolution tends to evolve as a whole toward increasing chromosome numbers by centric fission. Accordingly, our results support the fission hypothesis. We discussed the process of chromosome evolution based on the latest theory of the molecular structure of chromosomes, and reconfirmed that the fission burst is the prime motive force in long-term chromosome evolution, and is effective in minimizing the genetic risks due to deleterious reciprocal translocations and in increasing the potential of genetic divergence. Centric fusion plays a biological role in eliminating heterochromatin (C-bands), but is only a local reverse flow in contrast to the previously held views.

Animals↗
PubMed1998

Ancient conservation of trinucleotide microsatellite loci in polistine wasps.

Microsatellites have proven to be very useful genetic markers for studies of kinship, parentage, and gene mapping. If microsatellites are conserved among species, then those developed for one species can be used on related species, which would save the time and effort of developing new loci. We evaluated conservation of 27 trinucleotide loci that were derived from 2 species of Polistes wasps in cross-species applications on 27 species chosen from the major lineages of the Vespidae, which diverged as much as 144 million years ago. We further investigated cross-species polymorphism levels for 18 of the loci. There was a clear relationship between cladistic distance and both conservation of the priming sites and heterozygosity. However the loci derived from P. bellicosus were much more widely conserved and polymorphic than were those derived from P. annularis. The disparity in cross-species utility between these sets of loci means that caution should be used in generalizing from conservation rates derived from single species. We found no relationship between locus conservation or heterozygosity and GC content of flanks, repeat motif, repeat length, or heterozygosity in the original species, which suggests that generalizations from other studies reporting such patterns are premature.

Animals↗
PubMed1978

Colour receptors in the eye of the digger wasp, Sphex cognatus Smith: evaluation by selective adaptation.

Pigment granule migration in pigment cells and retinula cells of the digger wasp Sphex cognatus Smith was analysed morphologically after light adaptation to natural light, dark adaptation and after four selective chromatic adaptations in the range between 358 nm and 580 nm and used as the index of receptor cell sensitivity. The receptor region of each ommatidium consists of nine retinula cells which form a centrally located rhabdom. Two morphologically and physiologically different visual units can be described, defined by the arrangement of the rhabdomeric microvilli, the topographical relationship of the receptor cells with respect to the eye axes and the unique retinula cell screening pigmentation. These two different sets of ommatidia (type A and B) are randomly distributed in a ratio of 1:3 throughout the eye (Ribi, 1978b). Chromatic adaptation experiments with wavelengths of 358nm, 443nm, 523nm and 580nm and subsequent histological examination reveal two UV receptors, two blue receptors and four yellow-green receptors in type A ommatidia and two UV receptors and six green to yellow-green receptors in type B ommatidia. The pigments in cells surrounding each ommatidium (two primary pigment cells, 20 secondary pigment cells and four pigmented cone extensions) were not affected significantly by the adaptation experiments.

Adaptation, Physiological↗
PubMed1979

Neuronal connections in the ocellus of the wasp (Paravespula vulgaris L.).

Studies of the dorsal ocelli of the wasp Paravespula vulgaris (L.) led to the following results: Under a biconvex corneal lens, 150 microns in thickness, about 600 receptor cells are located. The rhabdomeres of two adjacent cells form a closed plate-like rhabdom (0.5--1.0 micron in thickness, 6 microns in width and 10--25 microns in depth or length). In the lateral ocellus the receptor cells synapse up to 8 ocellar nerve fibers, and in the median ocellus they synapse up to 16 (20--30 microns thick) ocellar nerve fibers. The ocellar synaptic plexus may display three types of synapses between the two types of neurons: (i) Receptor-cell axons are presynaptic to dendrites of the first-order interneurons. (ii) Dendrites of the first-order interneurons are presynaptic to receptor-cell axons. (iii) The subunits of a dendrite of first-order interneurons form synapses with each other.

Animals↗
PubMed1986

Reduction of high affinity glutamate uptake in rat hippocampus by two polyamine-like toxins isolated from the venom of the predatory wasp Philanthus triangulum F.

Two components of the venom of the predatory wasp Philanthus triangulum F. significantly reduce--to a greater or less extent--the high affinity uptake of glutamate in rat hippocampus. A concentration of 10 microM delta-PTX caused a reduction of 74%, while the other component, beta-PTX, at the same concentration, caused a reduction of 18%. Hence the effect of delta-PTX on high affinity glutamate uptake in the hippocampus is comparable with its effect on high affinity glutamate uptake in insect neuromuscular junctions. Contrary to our previous findings that beta-PTX has no effect on high affinity glutamate uptake in insect glutamatergic terminal axons, however, beta-PTX significantly reduces high affinity glutamate uptake in the hippocampus, albeit less effectively than delta-PTX.

Animals↗
PubMed1995

Effect of juvenile hormone on the embryogenesis of a polyembryonic wasp, Copidosoma floridanum, in vitro.

Single two-cell-stage embryos of a polyembryonic wasp Copidosoma floridanum cultured in 20 microliters droplets of culture medium developed to morulae at the same developmental rate as those in host eggs, but the subsequent development into polymorulae was inferior. This inferior development was markedly improved by addition of juvenile hormone (I, II, or III) or its analogues to the culture medium in a concentration-dependent manner.

Animals↗