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Behavioral and olfactory antennal responses of Solenopsis geminata (Fabricius) (Hymenoptera: Formicidae) workers to their dufour gland secretion
Brindis, Yolanda;Lachaud, Jean P.;Gómez Y Gómez, Benigno;Rojas, Julio C.;Malo, Edi A.;Cruz-López, Leopoldo;
Neotropical Entomology , 2008, DOI: 10.1590/S1519-566X2008000200004
Abstract: behavioral and electrophysiological tests were performed to evaluate the responses of workers of the ant solenopsis geminata (fabricius) from different size categories to dufour gland extracts. morphometric measures based in head widths across eyes were used to determine worker sizes. trail following response of different worker sizes to dufour gland extract from workers of different sizes was assessed. for each worker size category olfactory responses to dufour gland extracts were determined using electroantennography (eag). gas chromatography and mass spectrometry (gc-ms) were used to determine the chromatographic profile of dufour gland secretion for each worker size. morphometric measures permitted to classify the workers of s. geminata as large, medium and small workers. medium s. geminata workers displayed a significantly higher behavioral response to dufour gland extracts produced by medium size workers. similarly, medium workers showed a significantly higher eag response to dufour gland extracts produced by medium sized workers. chromatographic profile of dufour gland secretions produced by workers showed that each size category exhibited a characteristic profile of the three main components considered as potential trail pheromone constituents. this work showed that medium workers of s. geminata exhibited a high trail-following behavior as well as a high antennal response to dufour gland secretion. this and their relative abundance in field foraging areas, suggest that medium-sized workers are specialized in foraging activities.
Intraspecific and Intracolonial Variation in the Profile of Venom Alkaloids and Cuticular Hydrocarbons of the Fire Ant Solenopsis saevissima Smith (Hymenoptera: Formicidae)  [PDF]
Eduardo Gon?alves Paterson Fox,Adriana Pianaro,Daniel Russ Solis,Jacques Hubert Charles Delabie,Bruno Cunha Vairo,Ednildo de Alcantara Machado,Odair Correa Bueno
Psyche , 2012, DOI: 10.1155/2012/398061
Abstract: Fire ants are aggressive Neotropical ants that are extensively similar in general biology and morphology, making species identification difficult. Some fire ant species are top-rated pests spreading throughout the world by trade vessels. Many researchers attempted to sort between invasive and native species by using chemical characters, including patterns of venom alkaloids. The present study is the first to report intraspecific variation in some chemical characters, namely, cuticular hydrocarbons and venom alkaloids, within the Brazilian fire ant species Solenopsis saevissima and also reports on within-nest variations among members of different castes. Two different haplotypes (cryptic species) of S. saevissima were clearly identified, one presenting a predominant combination of the venom alkaloids cis- and trans-2-methyl-6-undecylpiperidine with the cuticular hydrocarbons C23, 3-Me-C23, 10-C25?:?1, C25, and 3-Me-C25, and the other a predominant combination of cis- and trans-2-methyl-6-tridecenylpiperidine with predominance of 12-C25?:?1, C25, 11-Me-C25, 3-Me-C25, 13-C27?:?1, C27, and 13-Me-C27. Intranest variations revealed that the proportions among these compounds varied sensibly among workers of different sizes, gynes, and males (no alkaloids were detected in the latter). Larva contained vestiges of the same compounds. The recorded chemical profiles are quite different from previous reports with S. saevissima samples from S?o Paulo. The finds thus support other recent claims that S. saevissima includes cryptic species; the study, moreover, adds the find that they can occur in the same geographical location. 1. Introduction The fire ants of the genus Solenopsis Westwood include species considered pests of worldwide importance, especially Solenopsis invicta Buren, which were accidentally transported to other countries outside their native range in South America. To date, fire ant invasion is a major concern in the USA. These ants, particularly those belonging to the Solenopsis saevissima species group, react aggressively when their earthen nests are disturbed. Their stings, in addition to pain, can cause serious anaphylactic reactions to sensitive subjects (e.g., [1]). The species Solenopsis saevissima Smith is native to South America and common in Brazil [2], wherein it is potentially responsible for over 35% of the registered accidents with insects (personal communication of Mário Sérgio Palma). This fire ant was not as extensively studied as other species officially considered pests, like S. invicta and Solenopsis richteri Forel. The fire ants are
Apoplastic Venom Allergen-like Proteins of Cyst Nematodes Modulate the Activation of Basal Plant Innate Immunity by Cell Surface Receptors  [PDF]
Jose L. Lozano-Torres,Ruud H. P. Wilbers,Sonja Warmerdam,Anna Finkers-Tomczak,Amalia Diaz-Granados,Casper C. van Schaik,Johannes Helder,Jaap Bakker,Aska Goverse,Arjen Schots,Geert Smant
PLOS Pathogens , 2014, DOI: doi/10.1371/journal.ppat.1004569
Abstract: Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of the host. However, the nature and mode of action of most immunomodulatory compounds in nematode secretions are not well understood. Here, we show that venom allergen-like proteins of plant-parasitic nematodes selectively suppress host immunity mediated by surface-localized immune receptors. Venom allergen-like proteins are uniquely conserved in secretions of all animal- and plant-parasitic nematodes studied to date, but their role during the onset of parasitism has thus far remained elusive. Knocking-down the expression of the venom allergen-like protein Gr-VAP1 severely hampered the infectivity of the potato cyst nematode Globodera rostochiensis. By contrast, heterologous expression of Gr-VAP1 and two other venom allergen-like proteins from the beet cyst nematode Heterodera schachtii in plants resulted in the loss of basal immunity to multiple unrelated pathogens. The modulation of basal immunity by ectopic venom allergen-like proteins in Arabidopsis thaliana involved extracellular protease-based host defenses and non-photochemical quenching in chloroplasts. Non-photochemical quenching regulates the initiation of the defense-related programmed cell death, the onset of which was commonly suppressed by venom allergen-like proteins from G. rostochiensis, H. schachtii, and the root-knot nematode Meloidogyne incognita. Surprisingly, these venom allergen-like proteins only affected the programmed cell death mediated by surface-localized immune receptors. Furthermore, the delivery of venom allergen-like proteins into host tissue coincides with the enzymatic breakdown of plant cell walls by migratory nematodes. We, therefore, conclude that parasitic nematodes most likely utilize venom allergen-like proteins to suppress the activation of defenses by immunogenic breakdown products in damaged host tissue.
Ants of the Genus Solenopsis Westwood 1840 (Hymenoptera: Formicidae) in the Arabian Peninsula with Description of a New Species, Solenopsis elhawagryi  [PDF]
Mostafa R. Sharaf, Abdulrahman S. Aldawood
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049485
Abstract: Ants of the genus Solenopsis Westwood in the Arabian Peninsula are revised. Six species are treated: Solenopsis elhawagryi Sharaf & Aldawood sp. n., S. geminata (Fabricius, 1804), S. omana Collingwood & Agosti, 1996, S. saudiensis Sharaf & Aldawood, 2011, S. sumara Collingwood & Agosti, 1996, and S. zingibara Collingwood & Agosti, 1996. Solenopsis elhawagryi is described from Beljorashi Governorate, Al Baha Province, Saudi Arabia, based on worker castes and the queen with notes on this species biology and ecology. Solenopsis sumara workers are redescribed and illustrated for the first time and a lectotype is designated. An identification key to the Arabian and Egyptian species is provided with scanning electron micrographs to facilitate species recognition.
Schistosoma mansoni Venom Allergen Like Proteins Present Differential Allergic Responses in a Murine Model of Airway Inflammation  [PDF]
Leonardo Paiva Farias,Dunia Rodrigues,Vinicius Cunna,Henrique Krambeck Rofatto,Eliana L. Faquim-Mauro,Luciana C. C. Leite
PLOS Neglected Tropical Diseases , 2012, DOI: 10.1371/journal.pntd.0001510
Abstract: Background The Schistosoma mansoni Venom-Allergen-Like proteins (SmVALs) are members of the SCP/TAPS (Sperm-coating protein/Tpx-1/Ag5/PR-1/Sc7) protein superfamily, which may be important in the host-pathogen interaction. Some of these molecules were suggested by us and others as potential immunomodulators and vaccine candidates, due to their functional classification, expression profile and predicted localization. From a vaccine perspective, one of the concerns is the potential allergic effect of these molecules. Methodology/Principal Findings Herein, we characterized the putative secreted proteins SmVAL4 and SmVAL26 and explored the mouse model of airway inflammation to investigate their potential allergenic properties. The respective recombinant proteins were obtained in the Pichia pastoris system and the purified proteins used to produce specific antibodies. SmVAL4 protein was revealed to be present only in the cercarial stage, increasing from 0–6 h in the secretions of newly transformed schistosomulum. SmVAL26 was identified only in the egg stage, mainly in the hatched eggs' fluid and also in the secretions of cultured eggs. Concerning the investigation of the allergic properties of these proteins in the mouse model of airway inflammation, SmVAL4 induced a significant increase in total cells in the bronchoalveolar lavage fluid, mostly due to an increase in eosinophils and macrophages, which correlated with increases in IgG1, IgE and IL-5, characterizing a typical allergic airway inflammation response. High titers of anaphylactic IgG1 were revealed by the Passive Cutaneous Anaphylactic (PCA) hypersensitivity assay. Additionally, in a more conventional protocol of immunization for vaccine trials, rSmVAL4 still induced high levels of IgG1 and IgE. Conclusions Our results suggest that members of the SmVAL family do present allergic properties; however, this varies significantly and therefore should be considered in the design of a schistosomiasis vaccine. Additionally, the murine model of airway inflammation proved to be useful in the investigation of allergic properties of potential vaccine candidates.
The Morphometry of Solenopsis Fire Ants  [PDF]
Walter R. Tschinkel
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0079559
Abstract: Size-related changes of body shape were explored in 15 polymorphic species of Solenopsis fire ants by analyzing body weight along with linear measurements of 24 body parts. Log regression slopes were used to detect changes of shape with increasing size. Within species, the largest workers weighed from about 5 to 30-fold as much as the smallest. The range of within-species body lengths varied from 1.6 mm to 4 mm. As worker size increased, the gaster tended to make up a larger proportion of body length, usually at the cost of the petiole, and rarely at the cost of head length or mesosoma length. In most, the relative volume of the gaster increased and that of the head and mesosoma decreased. Most also showed an increasingly “humped” mesosoma. For all species, head shape changed from barrel-shaped to heart-shaped as worker size increased. Antennae became relatively shorter as the relative size of the club decreased. Shape changes of the legs were more variable. S. geminata was exceptional in the extreme nature of its head shape change, and was the only species in which relative head volume increased and gaster volume decreased with increasing body size. With the exception of S. geminata, the allometric rules governing shape are remarkably similar across species, suggesting a genus-level developmental scheme that is not easily modified by evolution. It also suggests that the evolution of shape is highly constrained by these conserved growth rules, and that it acts primarily (perhaps only) through allometric growth. The results are discussed in light of the growth of imaginal discs in a resource-limited body (the pupa). The substantial variation of allometries within species and across localities is also discussed in relation to using allometric patterns to identify species or to construct phylogenies.
Comparative Immature Morphology of Brazilian Fire Ants (Hymenoptera: Formicidae: Solenopsis)
Eduardo Gon alves Paterson Fox,Daniel Russ Solis,M nica Lanzoni Rossi,Jacques Hubert Charles Delabie,Rodrigo Fernando de Souza,Odair Correa Bueno
Psyche , 2012, DOI: 10.1155/2012/183284
Abstract: Although common in Brazil, the biology of the fire ant Solenopsis saevissima (Smith) is still poorly studied. Larval descriptions are useful to genus-level ant systematics and sometimes to species-level taxonomy. This study presents a detailed description of juveniles of S. saevissima from Brazil, which were compared with Brazilian specimens of Solenopsis invicta Buren, Solenopsis geminata (Fabricius), and Solenopsis altipunctata Pitts. Different larval instars were separated by diagnostic morphological traits which were confirmed by observing moults. Reproductive larvae could be easily sorted by their distinctive body dimensions and shape. Contrary to previous reports on this species, the larvae of S. saevissima proved to be generally identical to those of S. invicta, while a few specimens resembled those of other close species, such as Solenopsis megergates Trager. Mature larvae thus presented considerable intraspecific variation in some characters recently proposed to aid fire ant species separation (morphology of head hairs).
A Naturally Occurring Hypoallergenic Variant of Vespid Antigen 5 from Polybia scutellaris Venom as a Candidate for Allergen-Specific Immunotherapy  [PDF]
Sabrina E. Vinzón, Cristina Marino-Buslje, Elena Rivera, Mirtha Biscoglio de Jiménez Bonino
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0041351
Abstract: Stings by insects from the Hymenoptera order are known to cause life-threatening allergic reactions and impair life quality. Despite the effectiveness of conventional vespid venom immunotherapy, more standardized and safer allergy vaccines are required and recombinant hypoallergenic variants are important clinical tools. Antigen 5 is a major allergen of vespid venoms and it was previously reported that Antigen 5 from Polybia scutellaris (Poly s 5) could be a hypoallergenic variant. In this work we assess the immunological behavior and allergenic activity of Poly s 5 in order to explore its suitability for specific immunotherapy. With this aim, recombinant Poly s 5 was expressed in Pichia pastoris and the presence of cross-reactive epitopes with Pol a 5, a known allergenic Antigen 5, was investigated both at the IgG and IgE levels, by ELISA assays and a basophil-mediator release assay respectively. A molecular model was also built to better understand the relationship between immunological and structural aspects. In mice, Poly s 5 induced IgG antibodies which cross-reacted with Pol a 5. However, Poly s 5 induced only minimal amounts of IgE and was a poor inducer of basophil-mediator release, even when the cells were sensitized with Pol a 5-specific IgE. Moreover, Poly s 5-specific serum showed a specific protective activity and was able to inhibit the Pol a 5-induced basophil degranulation. Structural analysis from the molecular model revealed that a few amino acid substitutions in the N-terminal region of Poly s 5 should lead to an alteration of the surface topography and electrostatic potential of the epitopes which could be responsible for its hypoallergenic behavior. These findings, taken as a whole, show that Poly s 5 is likely a naturally occurring hypoallergenic Antigen 5 variant.
Developmentally regulated expression, alternative splicing and distinct sub-groupings in members of the Schistosoma mansoni venom allergen-like (SmVAL) gene family
Iain W Chalmers, Andrew J McArdle, Richard MR Coulson, Marissa A Wagner, Ralf Schmid, Hirohisa Hirai, Karl F Hoffmann
BMC Genomics , 2008, DOI: 10.1186/1471-2164-9-89
Abstract: We report the first description of an SCP/TAPS gene family (Schistosoma mansoni venom allergen-like (SmVALs)) in the medically important Platyhelminthes (class Trematoda) and describe individual members' phylogenetic relationships, genomic organization and life cycle expression profiles. Twenty-eight SmVALs with complete SCP/TAPS domains were identified and comparison of their predicted protein features and gene structures indicated the presence of two distinct sub-families (group 1 & group 2). Phylogenetic analysis demonstrated that this group 1/group 2 split is zoologically widespread as it exists across the metazoan sub-kingdom. Chromosomal localisation and PCR analysis, coupled to inspection of the current S. mansoni genomic assembly, revealed that many of the SmVAL genes are spatially linked throughout the genome. Quantitative lifecycle expression profiling demonstrated distinct SmVAL expression patterns, including transcripts specifically associated with lifestages involved in definitive host invasion, transcripts restricted to lifestages involved in the invasion of the intermediate host and transcripts ubiquitously expressed. Analysis of SmVAL6 transcript diversity demonstrated statistically significant, developmentally regulated, alternative splicing.Our results highlight the existence of two distinct SCP/TAPS protein types within the Platyhelminthes and across taxa. The extensive lifecycle expression analysis indicates several SmVAL transcripts are upregulated in infective stages of the parasite, suggesting that these particular protein products may be linked to the establishment of chronic host/parasite interactions.Schistosomes are dioecious metazoan parasites of the phylum Platyhelminthes, which are estimated to infect more than 200 million people worldwide, with a further 600 million individuals living in the tropics and sub-tropics at risk of infection. The deposition of schistosome eggs within host tissues and the subsequent immune response elicited a
Carbon Dioxide, a Releaser for Digging Behavior in Solenopsis Geminata (Hymenoptera: Formicidae)  [cached]
Walter Hangartner
Psyche , 1969, DOI: 10.1155/1969/58428
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