Anatomy, ultrastructure, and functional morphology of the metathoracic tracheal defensive glands of the grasshopper Romalea guttata

1991 ◽  
Vol 69 (8) ◽  
pp. 2100-2108 ◽  
Author(s):  
Douglas W. Whitman ◽  
Johan P. J. Billen ◽  
David Alsop ◽  
Murray S. Blum
Keyword(s):  
Secretory Cell ◽  
Tactile Stimulation ◽  
Defensive Secretion ◽  
Smooth Endoplasmic Reticulum ◽  
Duct Cell ◽  
Secretory Cells ◽  
Glandular Tissue ◽  
Golgi Bodies ◽  
Romalea Guttata ◽  
Defensive Glands

In the lubber grasshopper Romalea guttata, the respiratory system produces, stores, and delivers a phenolic defensive secretion. The exudate is secreted by a glandular epithelium surrounding the metathoracic spiracular tracheal trunks. Embedded in the glandular tissue are multiple secretory units, each comprised of a basal secretory cell and an apical duct cell. Secretory cells have numerous mitochondria, a tubular, smooth endoplasmic reticulum, well-developed Golgi bodies, and a microvillilined vesicle thought to transfer secretion to the intracellular cuticular duct of a duct cell. Ducts empty into the metathoracic tracheal lumina where the exudate is stored behind the closed metathoracic spiracle. Tactile stimulation elicits secretion discharge, which begins when all spiracles except the metathoracic pair are closed and the abdomen is compressed. Increased hemostatic and pneumatic pressures drive air and secretion out of the spiracle with an audible hiss. Both metathoracic spiracles discharge simultaneously. The secretion erupts first as a dispersant spray, then as an adherent froth, and finally assumes the form of a slowly evaporating repellent droplet. Discharge force and number vary with eliciting stimuli, volume of stored secretion, and age, disturbance state, and temperature of the insect. Molting grasshoppers are unable to discharge because the stored exudate is lost with the shed cuticle. The advantages and limitations of a tracheal defensive system are discussed.

Novel exocrine glands in the hindleg tarsi of the ant Nothomyrmecia macrops

2000 ◽  
Vol 48 (6) ◽  
pp. 661 ◽  
Author(s):  
Johan Billen ◽  
Fuminori Ito ◽  
Christian Peeters
Keyword(s):  
Golgi Apparatus ◽  
Secretory Cell ◽  
Anterior Part ◽  
Duct Cell ◽  
Exocrine Gland ◽  
Secretory Cells ◽  
Exocrine Glands ◽  
The Third ◽  
Duct Cells

The third tarsomere of the hindlegs of both workers and queens of Nothomyrmecia macrops is almost entirely filled with a hitherto unknown exocrine gland (which does not occur in the closely related Myrmecia). Each of the approximately 30 secretory cells is connected to the outside via a duct cell. These open individually via large cuticular pores at the mesoventral side of the anterior part of the tarsomere. The diameter of the duct cells is narrow near the secretory cell, but gradually increases towards their opening site. The rounded secretory cells show a well developed Golgi apparatus and numerous clear vesicles. The function of this gland is not yet known, although its opening site may be indicative of the deposition of marking substances. At the mediodistal side of tarsomeres 2, 3 and 4 in the three pairs of legs, a glandular thickening of the epidermal epithelium occurs; this represents another novel exocrine structure in ants. This epithelial gland occurs in both Nothomyrmecia and Myrmecia.

The fine structure of Verson's glands in molting larvae of Calpodes ethlius (Hesperiidae, Lepidoptera)

1973 ◽  
Vol 51 (11) ◽  
pp. 1201-1210 ◽  
Author(s):  
Joan Lai-Fook
Keyword(s):  
Fine Structure ◽  
Secretory Cell ◽  
Duct Cell ◽  
Secretory Cells ◽  
Dense Granules ◽  
Cell Processes ◽  
Residual Bodies

The three cells which make up Verson's glands in Calpodes undergo drastic changes as they produce the cuticular linings and the secretions of the glands. The duct cell secretes only the typical cuticular duct. The saccule cell produces both the atypical cuticular saccule and dense granules which are discharged just before ecdysis. The secretory cell is much enlarged by vacuoles which remain separate until they too are discharged before ecdysis. Dense granules are also produced by the secretory cell. During deposition of the cuticular duct and saccule, their lumina arc packed with cell processes containing microtubules, which appear to arise from centrioles. Isolation and residual bodies appear in both the saccule and secretory cells even before discharge of their secretions.

scholarly journals The Platelet Dense Tubular System: Its Relationship of Prostaglandin Synthesis and Calcium Flux

1977 ◽  
Author(s):  
Jonathan M. Gerrard ◽  
James G. White
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Divalent Cations ◽  
Lipid Synthesis ◽  
Prostaglandin Synthesis ◽  
Calcium Flux ◽  
Secretory Cells ◽  
Ultrastructural Studies ◽  
Tubular System ◽  
Relationship Of ◽  
Columnar Cells

Evidence that the dense tubular system (DTS) is the site of platelet prostaglandin synthesis derives from several observations. First platelet peroxidase is localized in the DTS. Aminotriazole which inhibits the platelet peroxidase, inhibits prostaglandin biosynthesis at the same concentration. Secondly, a similar peroxidase occurs in the secretory cells of the sheep vesicular gland (SVG) and other cells known to be involved in prostaglandin synthesis. Third, the DTS is smooth endoplasmic reticulum (SER) and SER, which is abundant in the prostaglandin synthesizing columnar cells of the SVG secretory units, is known to be involved in lipid synthesis and metabolism in other tissues. Evidence that calcium is stored in the DTS derives from ultrastructural studies showing that the DTS is analagous to the sarcotubules of skeletal muscle, and that the DTS has the capacity to bind divalent cations. Evidence that calcium flux and prostaglandin synthesis are closely linked comes from several observations which suggest 1) that movement of calcium ions to the site where arachidonic acid (AA) is released from the precursor phospholipids to be used for synthesis of prostaglandins, stimulates the AA release and 2) that synthesized prostaglandin G2, prostaglandin H2, and/or thromboxane A2 initiate platelet contraction by moving calcium from the site of synthesis to the vicinity of the contractile actin and myosin. The results suggest that the DTS, prostaglandin and thromboxane synthesis, and calcium flux are integral parts of the system modulating platelet activation.

Ultrastructure of the female reproductive organs (ovary, vitellaria, and Mehlis' gland) of Halipegus eccentricus (Trematoda: Derogenidae)

1986 ◽  
Vol 64 (10) ◽  
pp. 2203-2212 ◽  
Author(s):  
Jon M. Holy ◽  
Darwin D. Wittrock
Keyword(s):  
Cell Types ◽  
Reproductive Organs ◽  
Golgi Body ◽  
Digenetic Trematode ◽  
Secretory Cells ◽  
Cortical Granules ◽  
Golgi Bodies ◽  
Transmission Electron ◽  
Vitelline Cells ◽  
Female Reproductive Organs

The female reproductive organs (ovary, vitellaria, and Mehlis' gland) of the digenetic trematode Halipegus eccentricus were studied by transmission electron microscopy. Oocytes entered diplotene while in the ovary and produced cortical granules and lipid bodies. Vitelline cells produced large amounts of eggshell protein but no yolk bodies. Two types of Mehlis' gland secretory cells were present, distinguishable by the morphology of their rough endoplasmic reticulum, Golgi bodies, and secretory bodies, and by the persistence of recognizable secretory material within the ootype lumen after exocytosis. In an attempt to standardize the nomenclature regarding the cell types of the Mehlis' gland, a classification that takes into account these four criteria is proposed. Two basic types of Golgi body organization were noted for the cells of the female reproductive system: a stack of flattened cisternae (Mehlis' gland alpha cells) and spherical Golgi bodies with vesicular cisternae (oocytes, vitelline cells, and Mehlis' gland beta cells).

Sensitivity of mammary secretory cell turnover to protein restriction and re-alimentation during early lactation

1997 ◽  
Vol 1997 ◽  
pp. 130-130
Author(s):  
M.G. Goodwill ◽  
N.S. Jessop ◽  
J.D. Oldham
Keyword(s):  
Cell Proliferation ◽  
Mammary Gland ◽  
Milk Production ◽  
Secretory Cell ◽  
Protein Restriction ◽  
Secretory Cells ◽  
Early Lactation ◽  
Cell Turnover ◽  
Lactational Performance

Milk production depends on both the number and activity of secretory cells within the mammary gland. Our earlier work showed the sensitivity of lactational performance to changes in diet during lactation (Goodwill et al, 1996). This study investigated the influence of protein undernutrition and re-alimentation on secretory cell proliferation and death in the mammary gland of rats during early lactation.

Describing the lactation curve of dairy animals

1999 ◽  
Vol 1999 ◽  
pp. 197-197 ◽  
Author(s):  
G. E. Pollott
Keyword(s):  
Secretory Cell ◽  
Empirical Models ◽  
Secretory Cells ◽  
Cell Numbers ◽  
Biological Meaning ◽  
Lactation Curve ◽  
Dairy Animals ◽  
The Difference ◽  
Daily Milk Yield ◽  
Daily Milk

Most functions used to describe the lactation curve of dairy animals are empirical in approach and result in parameters with little or no biological meaning. A new model for describing lactation based on the biology of the pregnant and lactating animal is proposed and compared to several empirical models (Wood, 1967; Grossman and Koops, 1988; Morant and Gnanasakthy, 1989).Lactation is thought of as the balance between an increase in secretory cell numbers (NSCP) and their later decline (NSCD). The difference between them is the number of active secretory cells, each of which secretes milk at a particular rate (S kg/cell/day). Thus daily milk yield (MY) = (NSCP – NSCD) x S.

scholarly journals Knockdown of p180 Eliminates the Terminal Differentiation of a Secretory Cell Line

2009 ◽  
Vol 20 (2) ◽  
pp. 732-744 ◽  
Author(s):  
Payam Benyamini ◽  
Paul Webster ◽  
David I. Meyer
Keyword(s):  
Cell Line ◽  
Mammalian Cells ◽  
Secretory Cell ◽  
Terminal Differentiation ◽  
Secretory Cells ◽  
Rnai Technology ◽  
Apo E ◽  
Secretory Phenotype ◽  
Rough Er ◽  
Necessary And Sufficient

We have previously reported that the expression in yeast of an integral membrane protein (p180) of the endoplasmic reticulum (ER), isolated for its ability to mediate ribosome binding, is capable of inducing new membrane biogenesis and an increase in secretory capacity. To demonstrate that p180 is necessary and sufficient for terminal differentiation and acquisition of a secretory phenotype in mammalian cells, we studied the differentiation of a secretory cell line where p180 levels had been significantly reduced using RNAi technology and by transiently expressing p180 in nonsecretory cells. A human monocytic (THP-1) cell line, that can acquire macrophage-like properties, failed to proliferate rough ER when p180 levels were lowered. The Golgi compartment and the secretion of apolipoprotein E (Apo E) were dramatically affected in cells expressing reduced p180 levels. On the other hand, expression of p180 in a human embryonic kidney nonsecretory cell line (HEK293) showed a significant increase in proliferation of rough ER membranes and Golgi complexes. The results obtained from knockdown and overexpression experiments demonstrate that p180 is both necessary and sufficient to induce a secretory phenotype in mammalian cells. These findings support a central role for p180 in the terminal differentiation of secretory cells and tissues.

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

2012 ◽  
Vol 62 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Maria Izabel Camargo-Mathias ◽  
Odair Correa Bueno ◽  
Alexsandro Santana Vieira
Keyword(s):  
Endoplasmic Reticulum ◽  
Squamous Epithelium ◽  
Smooth Endoplasmic Reticulum ◽  
Secretory Cells ◽  
Metapleural Gland ◽  
Atta Laevigata ◽  
Gland Cells ◽  
Transmission Electron ◽  
Secretion Granules ◽  
Myelin Figures

AbstractThe metapleural gland is considered a synapomorphy of ants, and is characterized as a paired structure located at the two postlateral ends of the thorax and secretes substances capable of inhibiting and controlling fungi and bacteria in the fungus garden and inside the nest. This study was aimed at investigating if and which are the ultrastructural differences in the metapleural gland cells of workers (three castes) of Atta laevigata using transmission electron microscopy (TEM). This study revealed the presence of Golgi regions, rough endoplasmic reticulum (lamellar and vesicular shapes), smooth endoplasmic reticulum, mitochondria (elongated, round-shaped), vacuoles, secretion granules with different electron densities, and myelin figures in the cytoplasm of secretory cells, indicating that this gland produces substances composed of proteins, lipids, and polysaccharides (glycogen in major workers). Lipid droplets and secretion granules were found very near to the microvilli, especially in minor workers. The intracellular portion of canaliculi exhibited invaginations that increased the surface area and modified the secretion produced by the secretory cells. In the three castes examined, the gland exhibited a reservoir preceded by a collecting chamber, both lined by a simple squamous epithelium with a cuticular intima. Workers of the three castes of A. laevigata might be involved in the production of secretion mainly composed of proteins with antibiotic properties and, minor workers, may be responsible for producing a wider variety of secretions compared to median and major workers in the colony.

scholarly journals Histological and histochemical aspects of the penial glands of Girardia biapertura Sluys, 1997 (Platyhelminthes, Tricladida, Paludicola)

2002 ◽  
Vol 62 (3) ◽  
pp. 547-555 ◽  
Author(s):  
S. T. SOUZA ◽  
A. M. LEAL-ZANCHET
Keyword(s):  
Secretory Cell ◽  
Ejaculatory Duct ◽  
Distal Portion ◽  
Proximal Region ◽  
Secretory Cells ◽  
Type I ◽  
Type Ii ◽  
Cell Type ◽  
Median Region

Girardia biapertura was described with sperm ducts penetrating the penis bulb, subsequently opening separately at the tip of the penis papilla and receiving the abundant secretion of penial glands. In the present work, the penial glands of this species have been histologically and histochemically analysed, and four types of secretory cells are distinguished. The openings of the penial glands into the intrabulbar and intrapapillar sperm ducts, designated here as intrapenial ducts, allow for the distinction between three histologically differentiated regions. The most proximal region possibly corresponds to the bulbar cavity of other freshwater triclads whereas the median and distal portions correspond to the ejaculatory duct. The proximal region of the intrapenial ducts receives mainly the openings of a secretory cell type (type I) that produces a proteinaceous secretion. A second type of secretory cell (type II) that secretes neutral mucopolyssacharides opens into the median region of the intrapenial ducts. The distal portion of the ducts receives two types of secretory cells (types III and IV) which secret glycoprotein and glycosaminoglycans, respectively. Types III and IV open also directly into the male atrium through the epithelium of the penis papilla. A comparison with the results presented here and those of other authors for species of Girardia is provided and the importance of the study of the penial glands for taxonomic characterisation of freshwater triclads is emphasised.

scholarly journals Membrane differentiation markers of airway epithelial secretory cells.

1988 ◽  
Vol 36 (2) ◽  
pp. 167-178 ◽  
Author(s):  
K Wasano ◽  
K C Kim ◽  
R M Niles ◽  
J S Brody
Keyword(s):  
Secretory Cell ◽  
Helix Pomatia ◽  
Apical Plasma Membrane ◽  
Secretory Cells ◽  
Membrane Glycoproteins ◽  
Differentiation Markers ◽  
Tracheal Epithelial ◽  
Spent Media

We describe here a system for culturing epithelial cells isolated from hamster trachea, which results in a highly enriched population of mucus-secreting cells. The culture system has enabled us to study the process of secretory cell differentiation in vitro. We found that epithelial secretory cells, in vivo and after 5 days in vitro, selectively bind the lectin Helix pomatia agglutinin (HPA) to apical and, to a lesser extent, basolateral surfaces as well as to mucin granules and intracellular secretory organelles. SDS-PAGE gels of detergent extracts of secretory cells cultured for 5 days reveal three HPA-binding glycoproteins with MW of 120 KD, 220 KD, and greater than 400 KD. The high-MW glycoprotein appears identical to mucin, since it is found in secretions from intact trachea and in spent media from 5-day cultures. It does not appear in spent media from 3-day cultures when cells contain few mucous granules and secrete little mucin. The 220 KD HPA-binding glycoprotein is also present in 5-day but not in 3-day cultures. In contrast, the 120 KD glycoprotein is present at both times. HPA-gp120 is a hydrophobic integral membrane protein, whereas HPA-gp220 and mucin are hydrophilic and are membrane associated. These studies define three membrane glycoproteins, one of which is specific for the tracheal epithelial secretory cell regardless of its mucous content, whereas the other two glycoproteins correlate with mucin secretion. They also demonstrate that, in the fully differentiated state, mucin is bound in a non-covalent fashion to the apical plasma membrane of the tracheal epithelial secretory cell.

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