PHEROMONES and EXOCRINE GLANDS IN ISOPTERA

Termites are eusocial insects that have a peculiar and intriguing system of communication using pheromones. The termite pheromones are composed of a blend of chemical substances and they coordinate different social interactions or activities, including foraging, building, mating, defense, and nestmate recognition. Some of these sociochemicals are volatile, spreading in the air, and others are contact pheromones, which are transmitted by trophallaxis and grooming. Among the termite semiochemicals, the most known are alarm, trail, sex pheromones, and hydrocarbons responsible for the recognition of nestmates. The sources of the pheromones are exocrine glands located all over the termite body. The principal exocrine structures considered pheromone-producing glands in Isoptera are the frontal, mandibular, salivary or labial, sternal, and tergal glands. The frontal gland is the source of alarm pheromone and defensive chemicals, but the mandibular secretions have been little studied and their function is not well established in Isoptera. The secretion of salivary glands involves numerous chemical compounds, some of them without pheromonal function. The worker saliva contains a phagostimulating pheromone and probably a building pheromone, while the salivary reservoir of some soldiers contains defensive chemicals. The sternal gland is the only source of trail-following pheromone, whereas sex pheromones are secreted by two glandular sources, the sternal and tergal glands. To date, the termite semiochemicals have indicated that few molecules are involved in their chemical communication, that is, the same compound may be secreted by different glands, different castes and species, and for different functions, depending on the concentration. In addition to the pheromonal parsimony, recent studies also indicate the occurrence of a synergic effect among the compounds involved in the chemical communication of Isoptera. (C) 2010 Elsevier B.V.

MRT Letter: A Novel Tegumental Gland in Female Imagoes of the Neotropical Termite Cornitermes cumulans (Isoptera, Termitidae, Syntermitinae)

In general, the exocrine glands of social insects are structures involved in the chemical communication associated with social life. Here, we report the discovery of an unknown tegumental gland that is present in the female imagoes of Cornitermes cumulans and occurs next to the well-developed tergal glands that have previously been described. The tegumental glands release their secretion in the intersegmental membrane and are composed of bicellular units, a secretory cell and a canal cell, that are closely located to the epidermal cells in the inferior part of the eighth and ninth tergites. The ultrastructure of the glandular cells showed abundant smooth endoplasmic reticulum, suggesting that the secretion may be pheromonal, although its function is still unknown. These exocrine structures are facing the tergal glands, and we hypothesized that they act synergistically with the tergal glands to generate short-range attraction during tandem behavior. Microsc. Res. Tech. 73: 1005-1008, 2010. (C) 2010 Wiley-Liss, Inc.

Secretory Profile of Metapleural Gland Cells of the Leaf-Cutting Ant Acromyrmex coronatus (Formicidae: Attini)

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Ultrastructural studies of the mandibular gland of Melipona quadrifasciata Lepeletier, 1836 (Apidae, Meliponini): a comparison between workers and queens

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Ultrastructural profile of metapleural gland cells of the ant Atta laevigata (F. Smith, 1858) (Formicidae: Attini)

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Structure and function of the foregut and salivary glands of the synanthropic diplopod Urostreptus atrobrunneus (Spirostreptidae)

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A comparative cytochemical study of the dufour gland in the eusocial bee Apis mellifera Linne, 1758 and Melipona bicolor Lepeletier, 1836

Dufour glands of Apis mellifera and Melipona bicolor were studied under light and transmission electron microscopy, using the cytochemical techniques of mercury bromophenol blue for protein detection, imidazole-buffered osmium tetroxide selective staining of unsaturated lipids, lanthanum nitrate for intercellular junction identification and zinc-iodide-osmium tetroxide for cytoplasmic endomembrane visualization. The results in both species corroborated the lipid nature of the gland secretion and showed in A. mellifera the poverty of the synthetic machinery in the worker gland cells in comparison with the queen, as expected by previous biochemical analyses. The pathway of the exogenous compounds of the secretion is intracellular, since substances can penetrate the cell folds and intercellular junctions, but their access to the, gland lumen is barred by the apical intercellular junctions.

Profiling the proteome complement of the secretion from hypopharyngeal gland of Africanized nurse-honeybees (Apis mellifera L.)

The protein complement of the secretion from hypopharyngeal gland of nurse-bees (Apis mellifera L.) was partially identified by using a combination of 2D-PAGE, peptide sequencing by MALDI-PSD/MS and a protein engine identification tool applied to the honeybee genome. The proteins identified were compared to those proteins already identified in the proteome complement of the royal jelly of the honey bees. The 2D gel electrophoresis demonstrated this protein complement is constituted of 61 different polypepides, from which 34 were identified as follows: 27 proteins belonged to MRJPs family, 5 proteins were related to the metabolism of carbohydrates and to the oxido-reduction metabolism of energetic Substrates, I protein was related to the accumulation of iron in honeybee bodies and I protein may be a regulator of MRJP-1 oligomerization. The proteins directly involved with the carbohydrates and energetic metabolisms were: alpha glucosidase, glucose oxidase and alpha amylase, whose are members of the same family of enzymes, catalyzing the hydrolysis of the glucosidic linkages of starch; alcohol dehydrogenase and aldehyde dehydrogenase, whose are constituents of the energetic metabolism. The results of the present manuscript support the hypothesis that the most of these proteins are produced in the hypoharyngeal gland of nurse-bees and secreted into the RJ. (C) 2004 Elsevier Ltd. All rights reserved.

Ultrastructural aspects of the mandibular gland of Melipona bicolor Lepeletier, 1836 (Hymenoptera : Apidae, Meliponini) in the castes

The mandibular gland in Melipona bicolor workers and queens was studied by scanning and transmission electron microscopy. There is no difference in the gland anatomy between the castes, but the transmission electron microscopy showed variation of the cellular ultrastructure according to the secretory phase of the gland in both castes. Smooth endoplasmic reticulum was abundant in the secretory cells of physogastric queens, indicating that these cells produce lipid secretion that is stored in granules with multi-lamellar bodies. Mitochondrial variations during the cell secretory cycle indicates their participation in the lipid synthesis. After secretion, release in the reservoir lumen through the collecting canals, the secretory cells contain many myelinic bodies, indicative of cellular regression. (C) 2004 Elsevier Ltd. All rights reserved.

Ultrastructure of the intramandibular gland of workers and queens of the stingless bee, Melipona quadrifasciata

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Size differences in the Dufour gland of Apis mellifera Linnaeus (Hymenoptera, Apidae) between and within the female castes

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Leaf-cutting ant faecal fluid and mandibular gland secretion: effects on microfungi spore germination

The mandibular gland secretion (MGS) and the faecal fluid (FF) of the leaf-cutting ant Atta sexdens rubropilosa Forel affected the spore germination of selected microfungi isolated from nests of this insect. MGS was more effective than the FF, completely inhibiting the spore germination of four out of six microfungi species.

Testosterone Promotes an Anabolic Increase in the Rat Female Prostate (Skene's Paraurethral Gland) Which Acquires a Male Ventral Prostate Phenotype

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SMase II, a new sphingomyelinase D from Loxosceles laeta venom gland: Molecular cloning, expression, function and structural analysis

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