Q112541853 Dotaz Zobrazit nápovědu
A great diversity of defensive chemicals has been described in termite soldiers equipped with a unique defensive organ, the frontal gland. Along with the functional diversity of these compounds, reflecting the evolutionary history of particular lineages and their defensive strategies, a considerable degree of chemical variability often occurs among species and populations. Thus, the chemistry of termite defense may provide information on the phylogeny and geographic dispersal of species and populations. In this paper, we report on the anatomy of the frontal gland and on the diversity of soldier defensive chemicals in the sand termite, Psammotermes hybostoma, from nine colonies and five different localities in Egypt. Using gas chromatography-mass spectrometry, a total of 30 sesquiterpene hydrocarbons, or their oxygenated derivatives, were detected, and the chemical identity of most of them identified. In addition, a ketone, an ester, and a diterpene were identified in some colonies. Within colonies, the chemical composition was stable and did not differ among soldier size categories. However, there were pronounced quantitative and qualitative differences in frontal gland chemicals among colonies and geographic locations. The findings are discussed in a broader comparison with other termite taxa.
- MeSH
- Isoptera anatomie a histologie chemie MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- seskviterpeny chemie izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Egypt MeSH
Within the multitude of chemical signals used by termites, the trail marking by means of pheromones is ubiquitous. Chemistry and biology of the trail-following communication have been described in more than 60 species from all families except for the Neotropical Serritermitidae. The chemical ecology of Serritermitidae is of special interest not only as a missing piece of knowledge on the diversity and evolution of isopteran pheromones but also because it may contribute to the debate on the phylogenetic position of this family, which is still unresolved. Therefore, we aimed in this study to identify the trail-following pheromone of the serritermitid Glossotermes oculatus. Based on a combined approach of analytical chemistry, electrophysiology, and behavioral bioassays, we propose (10Z,13Z)-nonadeca-10,13-dien-2-one to be the trail-following pheromone of G. oculatus, secreted by the sternal gland of pseudergates. Thus, we report on a new termite trail-following pheromone of an unexpected chemical structure, a ketone with 19 carbons, contrasting with unsaturated alcohols containing 12 carbons as trail-following pheromones in other advanced termite families. In addition to this unique trail-following pheromone, we also describe the sternal gland in pseudergates as an organ of unusual shape, size, and structure when compared with other isopteran species. These results underline the peculiarity of the family Serritermitidae and prompt our interest in the chemistry of pheromones in the other genus of the family, Serritermes.
- MeSH
- biotest MeSH
- chování zvířat účinky léků MeSH
- exokrinní žlázy anatomie a histologie chemie sekrece MeSH
- feromony analýza chemická syntéza chemie farmakologie sekrece MeSH
- Isoptera chemie fyziologie MeSH
- nenasycené mastné kyseliny analýza chemická syntéza chemie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In 1959, P. Karlson and M. Lüscher introduced the term 'pheromone', broadly used nowadays for various chemicals involved in intraspecific communication. To demonstrate the term, they depicted the situation in termite societies, where king and queen inhibit the reproduction of nest-mates by an unknown chemical substance. Paradoxically, half a century later, neither the source nor the chemical identity of this 'royal' pheromone is known. In this study, we report for the first time the secretion of polar compounds of proteinaceous origin by functional reproductives in three termite species, Prorhinotermes simplex, Reticulitermes santonensis and Kalotermes flavicollis. Aqueous washes of functional reproductives contained sex-specific proteinaceous compounds, virtually absent in non-reproducing stages. Moreover, the presence of these compounds was clearly correlated with the age of reproductives and their reproductive status. We discuss the putative function of these substances in termite caste recognition and regulation.
- MeSH
- hmyzí proteiny chemie metabolismus MeSH
- Isoptera klasifikace fyziologie MeSH
- rozmnožování MeSH
- sociální hierarchie MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- uhlovodíky analýza metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The peritrophic membrane in Acarus siro L. (Acari: Acaridae) is produced by distinct cells located in the ventriculus. In this study, the chitin inside the peritrophic membrane was detected using wheat germ-lectin conjugated with colloidal gold (10 nm). The chitin fibrils of the peritrophic membrane were a target for chitin effectors, including 1) chitinase, which hydrolyzes chitin fibers inside the peritrophic membrane; 2) calcofluor, which binds to chitin and destroys the peritrophic membrane mesh structure; and 3) diflubenzuron, which inhibits chitin synthesis. In addition, soybean trypsin protease inhibitor (STI) and cocktails of chitinase/calcofluor, diflubenzuron/calcofluor and chitinase/STI were tested. These compounds were supplemented in diets and an increase of population initiated from 50 individuals was observed after 21 d of cultivation. Final A. siro densities on experimental and control diets were compared. The chitin in the peritrophic membrane was determined to be a suitable target for novel acaricidal compounds for suppressing the population growth of A. siro. The most effective compounds were calcofluor and diflubenzuron, whereas the suppressive effects of chitinase and STI were low. The failure of chitinase could be due to its degradation by endogenous proteases. The combination of chitinase and STI suppressed A. siro population growth more effectively than when they were tested in oral admission separately. The combinations of calcofluor/chitinase or calcofluor/difluorbenzuron showed no additive effects on final A. siro density. The presence of chitin in peritrophic membrane provides a target for novel acaricidal compounds, which disrupt peritrophic membrane structure. The suitability of chitin effectors and their practical application in the management of stored product mites is discussed.
