Ultrastructure of the Lyonet's glands in larvae of Diatraea saccharalis Fabricius (Lepidoptera : Pyralidae)

The Lyonet's gland is found in Lepidoptera larvae, close to the excretory duct of the silk gland. The role played by this gland is still uncertain. This work aims to describe the ultrastructure of the Lyonet's bland in Diatraea saccharalis larvae, offering suggestions regarding its possible function. The insects were reared under laboratory-controlled conditions. The glands were conventionally prepared for transmission (TEM) and scanning (SEM) electron microscopy. SEM showed that Lyonet's glands are paired small structures located in the ventral side of the head. They are composed by clustered long cells resembling leaves. Under TEM observations, each cell is surrounded by a thin basal lamina and contains large stellate nucleus. The cytoplasm presents large and empty canaliculi with small microvilli. The basal plasma membrane forms numerous infoldings where numerous and well-developed mitochondria are concentrated. The cytoplasmic membrane system is poorly developed. Our ultrastructural results suggest that the Lyonet's gland in D. saccharalis larvae may be involved in the uptake of small molecules from the hemolymph no morphological evidences of macromolecules synthesis and secretion were noticed. The detection of nerve fibers in the gland suggest a neural control for the glandular cell function.

Gene discovery in Boophilus microplus, the cattle tick - the transcriptomes of ovaries, salivary glands, and hemocytes

The quest for new control strategies for ticks can profit from high throughput genomics. In order to identify genes that are involved in oogenesis and development, in defense, and in hematophagy, the transcriptomes of ovaries, hemocytes, and salivary glands from rapidly ingurgitating females, and of salivary glands from males of Boophilus microplus were PCR amplified, and the expressed sequence tags (EST) of random clones were mass sequenced. So far, more than 1,344 EST have been generated for these tissues, with approximately 30% novelty, depending on the the tissue studied. To date approximately 760 nucleotide sequences from B. microplus are deposited in the NCBI database. Mass sequencing of partial cDNAs of parasite genes can build up this scant database and rapidly generate a large quantity of useful information about potential targets for immunobiological or chemical control.

Presence of wall-devoid micro-organisms in hypopharyngeal glands of forager bees (Hymenoptera, Apidae)

The occurrence of mycoplasma-like bodies in the axial duct and intracellular canaliculli from hypopharyngeal glands of bees (Meliponinae and Apinae) is described. Since they are not found within cells and due to the absence of cellular alterations in the infected glands it is suggested that micro-organisms are not pathogenic to the bees.

SCANNING ELECTRON-MICROSCOPY OF THE RHODNIUS-NEGLECTUS (HEMIPTERA) LABIAL SALIVARY-GLANDS AFTER STARVATION

Labial salivary glands are found in the majority of insects. They are relatively large, extend back into the thorax, and in Rhodnius, they are cherry red in color due to a pigment derived from traces of hemoglobin absorbed form the gut. In most insects they are acinous shaped, with long excretion channels that present differentiated regions which from salivary reservoirs. The glands may be relatively simple or complexly branched and convoluted. In Rhodnius they are described as being unilobed with no traces of division. The main duct leaves the gland at its anterior extremity. The acini have different kinds of cells but all of them are seen as sources of secretion. Our material has a different shape due to the fact that the animals spent 20 days under starvation conditions. New data are also obtained through treatment with collagenase and HCl. The importance of the study of these glands lies in the fact that it will further understanding of the transmission of Chagas' disease.

Electrophoretical studies of proteins of the hypopharyngeal glands and of the larval food of Melipona quadrifasciata anthidioides Lep (Hymenoptera, Meliponinae)

The electrophoretical protein patterns of hypopharyngeal glands, larval food of Melipona, and royal jelly of Apis were compared.Since protein patterns of hypopharyngeal glands from newly emerged workers, brood cell provisioners and foragers are similar to freshly deposited larval food, the identical protein bands probably represent actual gland secretion. This suggests that, as in Apis, the glands secrete proteins to the larval food, and maintain this ability throughout life, although at slightly different intensities, according to the activity of the bees.The similarity on the electrophoretic profiles of the major larval food protein in Apis and Melipona is an interesting finding because of its probable evolutionary significance.

Morphological changes in the salivary glands of Amblyomma cajennense females (Acari : Ixodidae) in different feeding stages on rabbits at first infestation

This study examined salivary glands of unfed, partially engorged, and engorged females of the tick Amblyomma cajennense on rabbits at first infestation using histological and histochemical techniques. In type I acini, no significant changes were observed among the three feeding conditions. In type II acini of unfed females, c1, c2, and c4 cells were described for the first time in this species. In a comparison among the three feeding conditions, an increase in this acinus was observed, due to the increase in secretion in c1, c2, and c4 cells and the appearance of c3 cells. In engorged females, some cells were still active. Type III acini presented cells d, e, and f containing secretion in unfed females. In partially engorged females, these cells were devoid of secretion. In engorged females, type III acini exhibited a reduced lumen. After engorgement, all acini underwent a degenerative process, as observed in females after two to five days post-engorgement.

Trajectory of Water- and Fat-Soluble Dyes in the Grass-Cutting ant Atta capiguara (Hymenoptera, Formicidae): Evaluation of Infrabuccal Cavity, Post-Pharyngeal Glands and Gaster

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphological changes in the cephalic salivary glands of females and males of Apis mellifera and Scaptotrigona postica (Hymenoptera, Apidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of salivary glands extirpation on procreation in rats

The influence of extirpation of the submandibular and sublingual, parotid and all major salivary glands on pregnancy of rats was studied. The statistical analysis of the results indicated that there are statistically significant differences in the number of offsprings before and after extirpation of the salivary glands. The parotidectomized female rats presented the smallest number of offsprings as compared with other groups and presented some progressive sterility after the gland extirpation.

A morphological and ultrastructural study of the paracloacal (Scent) glands of the marsupial Metachirus nudicaudatus Geoffroy, 1803

Morphological and ultrastructural features of the paracloacal glands of Metachirus nudicaudatus are described. Two pairs of glands, one on the right and the other on the left of the anal canal, are formed, each consisting of a major and a minor portion. Their wall is made up of three layers: a mucosal, a muscular and an external capsule. The inner one is a mucosa the epithelium of which contains holocrine cells characterized by lipid droplets and intermediate filaments. The surrounding vascular lamina propria contains flattened tubular apocrine glands whose epithelial cells contain abundant endoplasmic reticulum, prominent Golgi complexes and numerous secretory granules. The middle layer is formed by skeletal striated muscle and the outer (third layer) consists of dense connective tissue. Each gland originates from a single duct. Transverse sections show that each duct, except in the female major gland, is in fact formed by a duct system. One of these ducts comes from the central cavity, lined by holocrine epithelium, and the others result from the branched tubular glands of the lamina propria.