Assessment of the In Vivo and In Vitro Release of Chemical Compounds from Vespa velutina.

Vespa velutina has been rapidly expanding throughout Galicia since 2012. It is causing human health risks and well-known losses in the beekeeping sector. Control methods are scarce, unspecific, and ineffective. Semiochemicals are insect-derived chemicals that play a role in communication and they could be used an integrated pest management tool alternative to conventional pesticides. A previous determination of the organic chemical profile should be the first step in the study of these semiochemicals. HS-SPME in living individuals and the sting apparatus extraction followed by GC-MS spectrometry were combined to extract a possible profile of these compounds in 43 hornets from Galicia. The identified compounds were hydrocarbons, ketones, terpenes, and fatty acid, and fatty acid esters. Nonanal aldehyde appeared in important concentrations in living individuals. While pentadecane, 8-hexyl- and ethyl oleate were mainly extracted from the venom apparatus. Ketones 2-nonanone, 2-undecanone and 7-nonen-2-one, 4,8-dimethyl- were identified by both procedures, as was 1,7-Nonadiene, 4,8-dimethyl-. Some compounds were detected for the first time in V. velutina such as naphthalene, 1,6-dimethyl-4-(1-methylethyl). The chemical profile by caste was also characterized.

Comparative Morphology of the Stinger in Social Wasps (Hymenoptera: Vespidae).

The physical features of the stinger are compared in 51 species of vespid wasps: 4 eumenines and zethines, 2 stenogastrines, 16 independent-founding polistines, 13 swarm-founding New World polistines, and 16 vespines. The overall structure of the stinger is remarkably uniform within the family. Although the wasps show a broad range in body size and social habits, the central part of the venom-delivery apparatus-the sting shaft-varies only to a modest extent in length relative to overall body size. What variation there is shows no apparent correlation with social habits. This is consistent with the hypothesis that stinger size is constrained by the demands of a flight-worthy body. The sting lancets bear distinct, acute barbs in all examined species except in members of the Stenogastrinae. Barbs vary considerably among species in number, their summed lengths, and the relative degree of serration (summed length relative to lancet width). Where they are numerous and strong, it increases the likelihood of the stinger remaining fatally embedded in the skin of a vertebrate adversary (sting autotomy). Although an index that combines the number and strength of barbs is a more natural measure of overall serration, the number of barbs alone is almost as good a predictor of the likelihood of sting autotomy. Across the family as a whole, the tendency to sting autotomy is concentrated in the swarm-founding New World polistines.

Biochemical characterization and in vitro biological activities of the epithelial cell extracts from Hypanus dipterurus spine.

Ocean organisms live in competitive environments that demand the production of poisons and toxins. In some cases, these substances have been used in the pharmaceutical industry for human disease treatments. Most fish poisons generally have potent cytolytic activity, probably through cardiovascular and neuromuscular effects. In the case of marine stingrays, the injuries made by their tail venom apparatus are caused by the mechanical penetration of their sting and a subsequent venom release. This study focused on the evaluation of substances with cytotoxic activity in the epithelium that covers the venom apparatus from the marine stingray Hypanus dipterurus. To demonstrate the above, the hemolytic, proteolytic and cytotoxic capacities of H. dipterurus epithelium substances were determined. Discs impregnated with epithelial extract were used on blood agar plates. The proteolytic activity was analyzed using casein as substrate and for gelatin the liquefaction activity test. To determine the cytotoxicity degree of the extracts, the proliferation and cell viability MTT bioassay was implemented on human cervical carcinoma cells (HeLa). The results showed that no hemolytic or proteolytic activity existed against casein associated with the epithelial extract, but gelatin hydrolysis and cytotoxic activity against the HeLa cell line were observed. This study concludes that the substances found in the epithelium covering the H. dipterurus stingray venom apparatus are a mixture of various proteins, among which, glycosylated anionic proteins represent a potential source of molecules with cytotoxic and hydrolytic activity.

De novo characterization of venom apparatus transcriptome of Pardosa pseudoannulata and analysis of its gene expression in response to Bt protein.

BACKGROUND: Pardosa pseudoannulata is a prevailing spider species, and has been regarded as an important bio-control agent of insect pests in farmland of China. However, the available genomic and transcriptomic databases of P. pseudoannulata and their venom are limited, which severely hampers functional genomic analysis of P. pseudoannulata. Recently high-throughput sequencing technology has been proved to be an efficient tool for profiling the transcriptome of relevant non-target organisms exposed to Bacillus thuringiensis (Bt) protein through food webs. RESULTS: In this study, the transcriptome of the venom apparatus was analyzed. A total of 113,358 non-redundant unigenes were yielded, among which 34,041 unigenes with complete or various length encoding regions were assigned biological function annotations and annotated with gene ontology and karyotic orthologous group terms. In addition, 3726 unigenes involved in response to stimulus and 720 unigenes associated with immune-response pathways were identified. Furthermore, we investigated transcriptomic changes in the venom apparatus using tag-based DGE technique. A total of 1724 differentially expressed genes (DEGs) were detected, while 75 and 372 DEGs were functionally annotated with KEGG pathways and GO terms, respectively. qPCR analyses were performed to verify the DEGs directly or indirectly related to immune and stress responses, including genes encoding heat shock protein, toll-like receptor, GST and NADH dehydrogenase. CONCLUSION: This is the first study conducted to specifically investigate the venom apparatus of P. pseudoannulata in response to Bt protein exposure through tritrophic chain. A substantial fraction of transcript sequences was generated by high-throughput sequencing of the venom apparatus of P. pseudoannulata. Then a comparative transcriptome analysis showing a large number of candidate genes involved in immune response were identified by the tag-based DGE technology. This transcriptome dataset will provide a comprehensive sequence resource for furture molecular genetic research of the venom apparatus of P. pseudoannulata.

A Venom Gland Extracellular Chitin-Binding-Like Protein from Pupal Endoparasitoid Wasps, Pteromalus Puparum, Selectively Binds Chitin.

Chitin-binding proteins (CBPs) are present in many species and they act in a variety of biological processes. We analyzed a Pteromalus puparum venom apparatus proteome and transcriptome and identified a partial gene encoding a possible CBP. Here, we report cloning a full-length cDNA of a sequence encoding a chitin-binding-like protein (PpCBP) from P. puparum, a pupal endoparasitoid of Pieris rapae. The cDNA encoded a 96-amino-acid protein, including a secretory signal peptide and a chitin-binding peritrophin-A domain. Phylogenetic analysis of chitin binding domains (CBDs) of cuticle proteins and peritrophic matrix proteins in selected insects revealed that the CBD of PpCBP clustered with the CBD of Nasonia vitripennis. The PpCBP is specifically expressed in the venom apparatus of P. puparum, mostly in the venom gland. PpCBP expression was highest at day one after adult eclosion and much lower for the following five days. We produced a recombinant PpCBP and binding assays showed the recombinant protein selectively binds chitin but not cellulose in vitro. We infer that PpCBP serves a structural role in the venom reservoir, or may be injected into the host to help wound healing of the host exoskeleton.

Morphological and histological characterization of production structures, storage and distribution of venom in the parasitic wasp Bracon vulgaris.

It was described the morphology and histological composition of the structures related to production, storage and distribution of Bracon vulgaris venom, a wasp that parasite their hosts after the inoculation of a venom which causes irreversible paralysis. Were found 22 glandular filaments, coated with secretory epithelium associated with a reservoir coated internally by a chitin layer and externally by striated muscular fibers. A valve mediates the passage of the toxin to venom duct towards the parasitoids sting.

Estudio histológico del tubo digestivo y aparato venenoso de Gemmula periscelida (Gastropoda: Turridae) / Histologic study of digestive tract and venom apparatus of Gemmula periscelida (Gastropoda: Turridae)

En el presente trabajo se describe anatómica e histológicamente el tubo digestivo y aparato venenoso de Gemmula periscelida (Gastropoda: Turridae) en ejemplares colectados al Noroeste de la Plataforma Continental Yucateca. Se determinó que el tipo de epitelio que reviste a cada una de las zonas del tubo digestivo (probóscide, esófago anterior, medio y posterior, estómago, glándula digestiva e intestino) y al aparato venenoso, es diferente a lo reportado para otros túrridos; por lo que se infiere el posible mecanismo de alimentación para esta especie.

In this paper we realized anatomical and histologically description of the digestive tract and venom apparatus of Gemmula periscelida (Gastropoda: Turridae) specimens collected northwest of the Yucatan Shelf. Results of analysis show that there are differences in the type of epithelium coating each of the areas of the digestive tract (proboscis, anterior, middle and posterior esophagus, stomach, digestive gland and intestine) and of a venom apparatus with respect to that reported for other turrid snails. This suggests the possible feeding mechanism for this species.

Morphology: histology and histochemistry of the venom apparatus of the centipede, Scolopendra valida (Chilopoda, Scolopendridae) / Morfología, histología e histoquímica del aparato venenoso del ciempiés: Scolopendra valida (Chilopoda, Scolopendridae)

Morphological, histological and histochemical characterizations of the venom apparatus of the centapede, S. valida have been investigated. The venom apparatus of Scolopendra valida consists of a pair of maxillipedes and venom glands situated anteriorly in the prosoma on either side of the first segment of the body. Each venom gland is continuous with a hollow tubular claw possessing a sharp tip and subterminal pore located on the outer curvature. The glandular epithelium is folded and consists of a mass of secretory epithelium, covered by a sheath of striated muscles. The secretory epithelium consists of high columnar venom-producing cells having dense cytoplasmic venom granules. The glandular canal lacks musculature and is lined with chitinous internal layer and simple cuboidal epithelium. The histochemical results indicate that the venom-producing cells of both glands elaborate glycosaminoglycan, acid mucosubstances, certain amino acids and proteins, but are devoid of glycogen. The structure and secretions of centipede venom glands are discussed within the context of the present results.

Fueron investigadas las características morfológicas, histológicas e histoquímicas del aparato venenoso del ciempiés, S. valida. El aparato venenoso de Scolopendra valida consta de un par de maxilopodos y glándulas de veneno situadas anteriormente en el prosoma, a cada lado del primer segmento del cuerpo. Cada glándula de veneno se continúa en una garra con una cavidad tubular que posee una punta afilada y un poro subterminal situado sobre la curvatura externa. El epitelio glandular es plegado y se compone de una masa de epitelio secretor, cubierto por una vaina de los músculos estriados. El epitelio secretor consiste en células columnares altas productoras de veneno con gránulos citoplasmáticos de veneno densos. El conducto glandular carece de musculatura y está revestido por capa interna quitinosa y epitelio cuboidal simple. Los resultados histoquímicos indican que las células productoras de veneno de ambas glándulas elaboran glucosaminoglucanos mucosustancias ácidas, ciertos aminoácidos y proteínas, pero carecen de glucógeno. La estructura y las secreciones de las glándulas de veneno del ciempiés son examinadas en el contexto de los presentes resultados.

Histology and histochemistry of the venom apparatus of the black scorpion Androctonus crassicauda (Olivier, 1807) (Scorpiones: Buthidae)

The venom apparatus of the black scorpion Androctonus crassicauda has been characterized histologically and histochemically in the present study. The results showed that this apparatus consists of paired venom glands, each of which initially presents its own canal and posteriorily both fuse into a single common one. Each gland is covered by a sheath of striated muscle and is lined with extensively folded secretory epithelium (formed of non-secretory and secretory venom-producing cells). The outcomes also revealed that the venom-producing cells of both glands produce neutral mucosubstances, sialomucins, sulfomucins and proteins, but are devoid of glycogen. Cysteine, tyrosine, tryptophan and arginine were also detected along with activities of acid and alkaline phosphatases, mitochondrial adenosine triphosphatase, aminopeptidase, cholinesterase and non-specific esterases. Structure and secretion of scorpion venom glands are discussed within the context of the present results.(AU)