The metapleural glands of fungus-growing and non-fungus-growing ants: Ultrastructural study

2014 ◽  
Vol 64 (3) ◽  
pp. 277-294
Author(s):  
Alexsandro Santana Vieira ◽  
Odair Correa Bueno ◽  
Maria Izabel Camargo-Mathias
Keyword(s):  
Antimicrobial Properties ◽  
Secretory Cells ◽  
Metapleural Gland ◽  
Transmission Electron ◽  
Metapleural Glands ◽  
Feeding Type ◽  
Leaf Cutting ◽  
Fungus Growing Ants ◽  
Secretory Capacity

The metapleural glands are considered an autapomorphic structure to ants and probable have an antibiotic or antifungal function. The present study was aimed at investigating the ultrastructural morphology of the metapleural glands in ants which have different feeding types: from fungus-growing ants, the higher and lower attine, and non-fungus-growing ants from the tribes Blepharidattini and Ectatommini analyzed by transmission electron microscopy. Plasma membrane invaginations in secretory cells of both fungus-growing and non-fungus-growing ants facilitate absorption of extracellular material from hemolymph. Higher and lower attines differed slightly from non-fungus-growing ants, by the presence of oval secretory cells and well-developed RER in the metapleural glands, which indicates a higher production of secretion in attines. Also, well-developed Golgi regions in the leaf-cutting ants and Ectatommini probably modify the secretions, produced by the secretory cell or coming of the hemolymph, into pheromone or antimicrobial compounds, the latter mainly in leaf-cutting ants. Still, the secretory cells of the metapleural gland of leaf-cutting ants exhibited several mitochondria near microvilli of the intracytoplasmic portion of the canaliculus, indicating an important role of the metapleural gland in the production and transport of secretion in metapleural gland of leaf-cutting ants. Thus, our work corroborates other findings, however our results add that the slight ultrastructural difference in the metapleural glands of leaf-cutting ants can be due to the feeding type (fungus-growing ants), resulting in greater secretory capacity and antimicrobial properties to combat pathogens (for example, micro-fungi parasites Escovopsis).

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.

Cephalic salivary gland ultrastructure of worker and queen eusocial bees (Hymenoptera, Apidae)

2009 ◽  
Vol 59 (3) ◽  
pp. 299-311 ◽  
Author(s):  
Carminda da Cruz-Landim ◽  
Silvana Beani Poiani
Keyword(s):  
Salivary Glands ◽  
Smooth Endoplasmic Reticulum ◽  
Secretory Cells ◽  
Apical Region ◽  
Transmission Electron ◽  
Basal Plasma ◽  
Eusocial Bees ◽  
Scaptotrigona Postica ◽  
Microscopy Techniques

AbstractEusocial bees present a pair of functional salivary glands in head, the cephalic salivary glands. These glands from workers and queens of two eusocial bee species, Apis mellifera and Scaptotrigona postica, were examined at different life stages using routine transmission electron microscopy techniques to correlate morphology and gland functions. Ultrastructural features of worker and queen glands ducts and secretory units were descriptively compared between species. The duct cells present basal plasma membrane invaginations reaching the apical region. Intercellular space and invaginations contain material of similar electron-density to the basal lamina, suggesting that substances might be directly absorbed from the hemolymph to the gland lumen. The secretory cells are rich in smooth endoplasmic reticulum, mitochondria, Golgi, and vesicles typical of lipid secretion. Secretory cells in S. postica become flattened with age in contrast to A. mellifera, where cells remained cuboidal. Mitochondria are associated with secretory vesicles and may become lipid deposits. A possible role of worker and queen secretion is discussed, taking changes in caste gland morphology and their function in the colony into account.

Carpellary appendages in Nymphaea and Victoria (Nymphaeaceae): evidence of their role as osmophores based on morphology, anatomy and ultrastructure

2019 ◽  
Vol 191 (4) ◽  
pp. 421-439 ◽  
Author(s):  
Lucía Melisa Zini ◽  
Beatriz Gloria Galati ◽  
Marina Gotelli ◽  
Gabriela Zarlavsky ◽  
María Silvia Ferrucci
Keyword(s):  
Visual Cues ◽  
Secretory Cells ◽  
Outer Cell ◽  
Transmission Electron ◽  
Nocturnal Species ◽  
Anatomy And Ultrastructure ◽  
Diurnal Species ◽  
Outer Cell Wall ◽  
Amorphous Substances

Abstract In flowers of Nymphaea and Victoria, carpellary appendages are regarded as structures related to pollination by deceit of night-blooming species. In this study, the anatomy, histochemistry and ultrastructure of carpellary appendages were analysed to investigate their possible role in the production of volatile compounds in nocturnal species Nymphaea amazonum, N. gardneriana, N. prolifera (Nymphaea subgenus Hydrocallis) and Victoria cruziana, and in diurnal species N. caerulea (Nymphaea subgenus Brachyceras). Carpellary appendages were studied using light microscopy and scanning and transmission electron microscopy from pre-anthesis to the second day of anthesis. Anatomical and ultrastructural features are characteristic of osmophores. In all species, the most frequent components in secretory cells are amyloplasts, lipid bodies, mitochondria, rough endoplasmic reticulum and elaioplasts. The epidermis and multilayered parenchyma accumulate abundant starch grains and lipophilic substances, both of which vanish during anthesis. Amorphous substances are deposited between the plasmalemma and the outer cell wall of epidermal cells, and are then released by cuticular diffusion. Odour production in carpellary appendages might be an ancient role of primary importance both in diurnal and nocturnal species that are pollinated by deceit. Olfactory and visual cues of small carpellary appendages in Nymphaea subgenus Brachyceras correspond to bee pollination, and large carpellary appendages in subgenus Hydrocallis and Victoria represent parallel functional specializations of the flowers to the attraction and reward for exclusive beetle pollination.

scholarly journals Regulation and specificity of antifungal metapleural gland secretion in leaf-cutting ants

2012 ◽  
Vol 279 (1745) ◽  
pp. 4215-4222 ◽  
Author(s):  
Sze Huei Yek ◽  
David R. Nash ◽  
Annette B. Jensen ◽  
Jacobus J. Boomsma
Keyword(s):  
Immune System ◽  
Fungal Species ◽  
Gland Secretion ◽  
Exocrine Glands ◽  
Controlled Experiments ◽  
Metapleural Gland ◽  
Defence System ◽  
Metapleural Glands ◽  
Leaf Cutting

Ants have paired metapleural glands (MGs) to produce secretions for prophylactic hygiene. These exocrine glands are particularly well developed in leaf-cutting ants, but whether the ants can actively regulate MG secretion is unknown. In a set of controlled experiments using conidia of five fungi, we show that the ants adjust the amount of MG secretion to the virulence of the fungus with which they are infected. We further applied fixed volumes of MG secretion of ants challenged with constant conidia doses to agar mats of the same fungal species. This showed that inhibition halos were significantly larger for ants challenged with virulent and mild pathogens/weeds than for controls and Escovopsis -challenged ants. We conclude that the MG defence system of leaf-cutting ants has characteristics reminiscent of an additional cuticular immune system, with specific and non-specific components, of which some are constitutive and others induced.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Scanning and Transmission Electron Microscopy of the Endometrium in Women with Ovarian Dysgenesis (Turner'S Syndrome)

1976 ◽  
Vol 34 ◽  
pp. 148-149
Author(s):  
A. González-Angulo ◽  
S. Armendares-Sagrera ◽  
I. Ruíz de Chávez ◽  
H. Marquez-Monter ◽  
R. Aznar
Keyword(s):  
Surface Epithelium ◽  
Secretory Cells ◽  
Turner's Syndrome ◽  
Ciliated Cells ◽  
Turner’S Syndrome ◽  
Exogenous Hormone ◽  
Ovarian Dysgenesis ◽  
Transmission Electron ◽  
Normal Women ◽  
Microscopy Examination

It is a well documented fact that endometrial hyperplasia and adenocarcinoma may develop in women with Turner's syndrome who had received unopposed estrogen treatment (1), as well as in normal women under contraceptive medication with the sequential regime (2). The purpose of the present study was to characterize the possible changes in surface and glandular epithelium in these women who were treated with a sequential regime for a period of between three and eight years. The aim was to find organelle modifications which may lead to the understanding of the biology of an endometrium under exogenous hormone stimulation. Light microscopy examination of endometrial biopsies of nine patients disclosed a proliferative pattern; in two of these, there was focal hyperplasia. With the scanning electron microscope the surface epithelium in all biopsies showed secretory cells with microvilli alternating with non secretory ciliated cells. Regardless of the day of the cycle all biopsies disclosed a large number of secretory cells rich in microvilli (fig.l) with long and slender projections some of which were branching (fig. 2).

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Ultrastructural studies of the relationship between actin filaments and secretory granules

1990 ◽  
Vol 48 (3) ◽  
pp. 458-459
Author(s):  
Ellen Holm Nielsen
Keyword(s):  
Electron Microscopy ◽  
Colloidal Gold ◽  
Actin Filaments ◽  
Secretory Granules ◽  
Secretory Cells ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Granule Membrane ◽  
Ultrathin Sections ◽  
Lowicryl K4m

In secretory cells a dense and complex network of actin filaments is seen in the subplasmalemmal space attached to the cell membrane. During exocytosis this network is undergoing a rearrangement facilitating access of granules to plasma membrane in order that fusion of the membranes can take place. A filamentous network related to secretory granules has been reported, but its structural organization and composition have not been examined, although this network may be important for exocytosis.Samples of peritoneal mast cells were frozen at -70°C and thawed at 4°C in order to rupture the cells in such a gentle way that the granule membrane is still intact. Unruptured and ruptured cells were fixed in 2% paraformaldehyde and 0.075% glutaraldehyde, dehydrated in ethanol. For TEM (transmission electron microscopy) cells were embedded in Lowicryl K4M at -35°C and for SEM (scanning electron microscopy) they were placed on copper blocks, critical point dried and coated. For immunoelectron microscopy ultrathin sections were incubated with monoclonal anti-actin and colloidal gold labelled IgM. Ruptured cells were also placed on cover glasses, prefixed, and incubated with anti-actin and colloidal gold labelled IgM.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

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