scholarly journals Fine structure of the integument of Argas (Persicargas) persicus (Oken) (Ixodoidea: Argasidae)

2005 ◽  
Vol 16 (4) ◽  
Author(s):  
Ashraf Montasser ◽  
Amr Amin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Rough Endoplasmic Reticulum ◽  
Epidermal Cells ◽  
Argas Persicus ◽  
Dermal Glands ◽  
Transmission Electron ◽  
Surface Pores

The integument of Argas persicus was investigated using light, scanning and transmission electron microscopy. The study revealed that two layers, viz. an outer epicuticle and an inner procuticle, form the cuticle. The epicuticle includes wax, cuticulin and protein epicuticular layers. The wax layer carries numerous crater-like deposits, oval or circular discs and numerous infoldings. The procuticle contains an exo-, endo- and a subcuticle.Underlining the cuticle, flattened epidermal cells are connected via desmosomes and contain rough endoplasmic reticulum, free ribosomes and mitochondria. Scattered dermal glands are located beneath the cuticle and are continuous with the outside through dermal ducts and surface pores.

Ultrastructure of Solitary Enchondromas

1984 ◽  
Vol 9 (1) ◽  
pp. 95-97 ◽  
Author(s):  
MARILYN L. ZIMNY ◽  
I. REDLER
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Cell Types ◽  
Transmission Electron ◽  
The Matrix ◽  
Small Bones ◽  
Dying Cells ◽  
Myelin Figures

Solitary enchondromas obtained from the small bones of the hand were studied with transmission electron microscopy. Three cell types were seen as follows: (1) young looking, active cells with extensive dilated rough endoplasmic reticulum and well defined Golgi and mitochondria; (2) older looking, degenerating cells with dilated rough endoplasmic reticulum, well defined Golgi, glycogen masses, vacuoles containing tropocollagen, lipid and myelin figures; and (3) dying cells showing loss of cell membrane and lysosomal-like bodies. A young chondroblastic cell may try to mature, become a normal chondrocyte that produces normal matrix but it does not succeed and dies. Enchondromal cells are not capable of forming tropocollagen or synthesizing proteoglycans for the matrix.

scholarly journals Comparative stereologic study between secretory and maturation ameloblasts in rat incisors

2003 ◽  
Vol 11 (2) ◽  
pp. 144-149 ◽  
Author(s):  
Gerson Francisco de Assis ◽  
Daniel Araki Ribeiro ◽  
Patrícia Danieli Campos ◽  
Tania Mary Cestari ◽  
Rumio Taga
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Volume Ratio ◽  
Maturation Phase ◽  
Transmission Electron ◽  
Morphologic Variation ◽  
Nucleus Volume

The ameloblasts both in secretion phase and in smooth-ended ameloblasts in maturation phase were studied using stereologic methods in transmission electron microscopy (TEM). From secretion to maturation phase of amelogenesis, the nucleus volume decreased 23% and cytoplasm volume did not show significant changes; the total volume and surface of the rough endoplasmic reticulum (RER) decreased 74% and 90%, respectively, and of the mitochondria increased 742% and 384%, respectively; the surface-to-volume ratio for RER and mitochondria decrease 59% and 42%, respectively; and the predominantly apical secretory granules disappeared joined at Tomes’ process and lysosomes and phagic vacuoles have appeared principly in supranuclear cytoplasm. Although significant morphologic variation occurs from the secretory to the maturation phase of the ameloblasts, their cytoplasm volume remains unaltered.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

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.

scholarly journals Pollen, Tapetum, and Orbicule Development inColletia paradoxaandDiscaria americana(Rhamnaceae)

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
M. Gotelli ◽  
B. Galati ◽  
D. Medan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Ultrastructural Changes ◽  
Transmission Electron ◽  
The Family ◽  
Tapetal Cells ◽  
Grain Formation

Tapetum, orbicule, and pollen grain ontogeny inColletia paradoxaandDiscaria americanawere studied with transmission electron microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr). This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage.

scholarly journals Enigmatic origin of the poxvirus membrane from the endoplasmic reticulum shown by 3D imaging of vaccinia virus assembly mutants

2017 ◽  
Vol 114 (51) ◽  
pp. E11001-E11009 ◽  
Author(s):  
Andrea S. Weisberg ◽  
Liliana Maruri-Avidal ◽  
Himani Bisht ◽  
Bryan T. Hansen ◽  
Cindi L. Schwartz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Vaccinia Virus ◽  
Virus Assembly ◽  
Transmembrane Protein ◽  
Membrane Dynamics ◽  
Deletion Mutants ◽  
Viral Membrane ◽  
Transmission Electron

The long-standing inability to visualize connections between poxvirus membranes and cellular organelles has led to uncertainty regarding the origin of the viral membrane. Indeed, there has been speculation that viral membranes form de novo in cytoplasmic factories. Another possibility, that the connections are too short-lived to be captured by microscopy during a normal infection, motivated us to identify and characterize virus mutants that are arrested in assembly. Five conserved vaccinia virus proteins, referred to as Viral Membrane Assembly Proteins (VMAPs), that are necessary for formation of immature virions were found. Transmission electron microscopy studies of two VMAP deletion mutants had suggested retention of connections between viral membranes and the endoplasmic reticulum (ER). We now analyzed cells infected with each of the five VMAP deletion mutants by electron tomography, which is necessary to validate membrane continuity, in addition to conventional transmission electron microscopy. In all cases, connections between the ER and viral membranes were demonstrated by 3D reconstructions, supporting a role for the VMAPs in creating and/or stabilizing membrane scissions. Furthermore, coexpression of the viral reticulon-like transmembrane protein A17 and the capsid-like scaffold protein D13 was sufficient to form similar ER-associated viral structures in the absence of other major virion proteins. Determination of the mechanism of ER disruption during a normal VACV infection and the likely participation of both viral and cell proteins in this process may provide important insights into membrane dynamics.

Direct Observation of Fine Structure within Images of Atoms in Crystals by Transmission Electron Microscopy

1977 ◽  
Vol 42 (3) ◽  
pp. 1073-1074 ◽  
Author(s):  
Hatsujiro Hashimoto ◽  
Hisamitsu Endoh ◽  
Takayoshi Tanji ◽  
Akishige Ono ◽  
Eiichi Watanabe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Direct Observation ◽  
Transmission Electron

scholarly journals Effects of ubiquitin C-terminal hydrolase L1 deficiency on mouse ova

Reproduction ◽  
2012 ◽  
Vol 143 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Sayaka Koyanagi ◽  
Hiroko Hamasaki ◽  
Satoshi Sekiguchi ◽  
Kenshiro Hara ◽  
Yoshiyuki Ishii ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Proteomic Analysis ◽  
Ubiquitin Proteasome System ◽  
Underlying Mechanism ◽  
Wild Type ◽  
Transmission Electron ◽  
Ubiquitin Proteasome

Maternal proteins are rapidly degraded by the ubiquitin–proteasome system during oocyte maturation in mice. Ubiquitin C-terminal hydrolase L1 (UCHL1) is highly and specifically expressed in mouse ova and is involved in the polyspermy block. However, the role of UCHL1 in the underlying mechanism of polyspermy block is poorly understood. To address this issue, we performed a comprehensive proteomic analysis to identify maternal proteins that were relevant to the role of UCHL1 in mouse ova using UCHL1-deficientgad. Furthermore, we assessed morphological features ingadmouse ova using transmission electron microscopy. NACHT, LRR, and PYD domain-containing (NALP) family proteins and endoplasmic reticulum (ER) chaperones were identified by proteomic analysis. We also found that the ‘maternal antigen that embryos require’ (NLRP5 (MATER)) protein level increased significantly ingadmouse ova compared with that in wild-type mice. In an ultrastructural study,gadmouse ova contained less ER in the cortex than in wild-type mice. These results provide new insights into the role of UCHL1 in the mechanism of polyspermy block in mouse ova.

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