scholarly journals Improved analysis method of neuromuscular junction in Drosophila larvae by transmission electron microscopy

2021 ◽  
Author(s):  
Gan Guangming ◽  
Chen Mei ◽  
Zhang Chenchen ◽  
Xie Wei ◽  
Geng Junhua
Keyword(s):  
Electron Microscopy ◽  
Neuromuscular Junction ◽  
Neuromuscular Junctions ◽  
Uranyl Acetate ◽  
Metal Mesh ◽  
Transmission Electron ◽  
Neuroscience Research ◽  
Drosophila Larvae ◽  
Ultrathin Sections ◽  
Small Field Of View

AbstractThe Drosophila neuromuscular junction is an excellent model for neuroscience research. However, the distribution of neuromuscular junctions is very diffuse, and it is not easy to accurately locate during ultrathin sectioning, which seriously interferes with the ultrastructural analysis under electron microscopy that only has a small field of view. Here, we reported an efficient method for acquiring the ultrastructural picture of neuromuscular junctions in Drosophila larva under electron microscopy. The procedure was as follows: first, the larval sample of body wall muscle was placed between the metal mesh and was dehydrated with alcohol and infiltrated with epoxy resin to prevent the sample from curling or bending, after it was dissected and fixed into thin slices. Second, the sample was embedded in resin into a flat sheet to facilitate the positioning of the muscles. Third, carefully and gradually remove the excess resin and the cuticle of the larvae, cut off both ends of the special body segment, and trim the excess specific muscles according to the recommended ratio of trimming muscles, which would reduce the workload exponentially. At last, the trimmed sample were prepared into serial about 1000 ultrathin sections that was about total 80 microns thickness, and 30–40 sections were gathered into a grid to stain with lead citrate and uranyl acetate. This method could also be applied to the other small and thin samples such as the Drosophila embryo, ventral nerve cord and brain.

The Ultrastructure of Lymphocytic Hypophysitis

1981 ◽  
Vol 39 ◽  
pp. 466-467
Author(s):  
S.L. Asa ◽  
K. Kovacs ◽  
J. M. Bilbao ◽  
R. G. Josse ◽  
K. Kreines
Keyword(s):  
Electron Microscopy ◽  
Plasma Cells ◽  
Secretory Granules ◽  
Sella Turcica ◽  
Uranyl Acetate ◽  
Lymphocytic Hypophysitis ◽  
Pituitary Cells ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Mass Lesions

Seven cases of lymphocytic hypophysitis in women have been reported previously in association with various degrees of hypopituitarism. We report two pregnant patients who presented with mass lesions of the sella turcica, clinically mimicking pituitary adenoma. However, pathologic examination revealed extensive infiltration of the anterior pituitary by lymphocytes and plasma cells with destruction of the gland. To our knowledge, the ultrastructural features of lymphocytic hypophysitis have not been studied so far.For transmission electron microscopy, tissue from surgical specimens was fixed in glutaraldehyde, postfixed in OsO4, dehydrated and embedded in epoxy-resin. Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a Philips 300 electron microscope.Electron microscopy revealed adenohypophysial cells of all types exhibiting varying degrees of injury. In the areas of most dense inflammatory cell infiltration pituitary cells contained large lysosomal bodies fusing with secretory granules (Fig. 1), as well as increased numbers of swollen mitochondria, indicating oncocytic transformation (Fig. 2).

Electron microscopy of the changes in the sperm head curvature of the palm squirrel (Funambulus Penanti)

1993 ◽  
Vol 51 ◽  
pp. 334-335
Author(s):  
S. R. Bawa ◽  
R. Bawa ◽  
H. K. Bains
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Sperm Head ◽  
Lead Citrate ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Epididymal Spermatozoa

Examination of ultrathin sections of the spermatozoa recovered from the epididymis of the Indian palm squirrel (Funambulus penanti) indicates that the sperm head undergoes changes in its curvature during epididymal transit.Testis and epididymis of an adult male squirrel were dissected and small pieces of tissue fixed in 2.0% glutaraldehyde in 0.1 M phosphate buffer and post-fixed in osmium tetroxide. After dehydration in graded acetone the material was embedded in Araldite. Ultrathin sections were cut on a Reichert Jung Ultracut, picked-up on copper grids, stained with Reynold’s lead citrate-uranyl acetate and examined with a JEOL 1200 EX transmission electron microscope.Ultrathin sections of the caput epididymal spermatozoa reveal that their plasma membrane is adherent to the underlying acrosome (Figure 1). When these spermatozoa reach the corpus epididymis the plasma membrane surrounding the head becomes ruffled (Figure 2). The lifting-up of the plasma membrane around the head is restricted to the posterior bend of the acrosome.

Platinum Compounds as Stains for Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 230-231
Author(s):  
S. K. Aggarwal ◽  
P. McAllister ◽  
R. W. Wagner ◽  
B. Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Hela Cells ◽  
Uranyl Acetate ◽  
Sarcoma 180 ◽  
Platinum Compounds ◽  
Kb Cells ◽  
En Bloc ◽  
Human Lymphoma ◽  
Ultrathin Sections ◽  
Blue Coloration

Uranyl acetate has been used as an electron stain for en bloc staining as well as for staining ultrathin sections in conjunction with various lead stains (Fig. 1). Present studies reveal that various platinum compounds also show promise as electron stains. Certain platinum compounds have been shown to be effective anti-tumor agents. Of particular interest are the compounds with either uracil or thymine as one of the ligands (cis-Pt(II)-uracil; cis-Pt(II)-thymine). These compounds are amorphous, highly soluble in water and often exhibit an intense blue coloration. These compounds show enough electron density to be used as stains for electron microscopy. Most of the studies are based on various cell lines (human AV, cells, human lymphoma cells, KB cells, Sarcoma-180 ascites cells, chick fibroblasts and HeLa cells) while studies on tissue blocks are in progress.

Magnesium and sulfur in mast cell and basophil granules of lower vertebrates in relation with histamine

1992 ◽  
Vol 50 (2) ◽  
pp. 1596-1597
Author(s):  
Kenichi Takaya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mast Cell ◽  
Mast Cells ◽  
Tree Frog ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Fresh Frozen ◽  
Ultrathin Sections

Mast cell and basophil granules of the vertebrate contain heparin or related sulfated proteoglycans. Histamine is also present in mammalian mast cells and basophils. However, no histamine is detected in mast cell granules of the amphibian or fish, while it is shown in those of reptiles and birds A quantitative x-ray microanalysis of mast cell granules of fresh frozen dried ultrathin sections of the tongue of Wistar rats and tree frogs disclosed high concentrations of sulfur in rat mast cell granules and those of sulfur and magnesium in the tree frog granules. Their concentrations in tree frog mast cell granules were closely correlated (r=0.94).Fresh frozen dried ultrathin sections and fresh air-dried prints of the tree frog tongue and spleen and young red-eared turtle (ca. 6 g) spleen and heart blood were examined by a quantitative energy-dispersive x-ray microanalysis (X-650, Kevex-7000) for the element constituents of the granules of mast cells and basophils. The specimens were observed by transmission electron microscopy (TEM) (80-200 kV) and followed by scanning transmission electron microscopy (STEM) under an analytical electron microscope (X-650) at an acceleration voltage of 40 kV and a specimen current of 0.2 nA. A spot analysis was performed in a STEM mode for 100 s at a specimen current of 2 nA on the mast cell and basophil granules and other areas of the cells. Histamine was examined by the o-phthalaldehyde method.

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.

scholarly journals FINE STRUCTURES OF INTRACYTOPLASMIC ORGANELLES OF MYCOBACTERIA

1961 ◽  
Vol 9 (3) ◽  
pp. 597-608 ◽  
Author(s):  
Masaatsu Koike ◽  
Kenji Takeya
Keyword(s):  
Electron Microscopy ◽  
Lamellar Structure ◽  
Cytoplasmic Membrane ◽  
Uranyl Acetate ◽  
Low Density ◽  
Nuclear Region ◽  
Unit Membrane ◽  
Veronal Buffer ◽  
Ultrathin Sections ◽  
Fine Structures

The fine structure of the intracytoplasmic organelles of mycobacteria was studied by means of electron microscopy of ultrathin sections. A well-preserved nuclear apparatus was obtained by fixation with OsO4 in acetate-veronal buffer, containing calcium and tryptone, or in collidine-HCl buffer, followed by uranyl-acetate treatment and embedding in araldite. A low density nuclear region was filled with fine fibrils, 30 A in diameter, in parallel or concentric arrangement. A membranous organelle, tentatively designated as "lamellar structure," consists of unit membranes in lamellar arrangement. The thickness of each lamella in this membranous organelle coincides with that of the three-layered cytoplasmic membrane Moreover, the continuity of this unit membrane with the cytoplasmic membrane was demonstrated.

Postero-Lateral Glands of Temnocephala Minor Haswell, 1888 (Platyhelminthes: Temnocephalida)

1996 ◽  
Vol 44 (1) ◽  
pp. 69
Author(s):  
LRG Cannon ◽  
NA Warson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Lateral Margin ◽  
Freshwater Crayfish ◽  
Cherax Destructor ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Whole Mounts

Temnocephala minor Haswell, 1888 lives ectosymbiotically on the surface of the freshwater crayfish Cherax destructor in the Murray-Darling drainages of Australia. Some glands open on the postero-lateral margin and, being moderately refractory to many stains, can be overlooked in whole mounts and sections, and were, in fact, missed by Haswell. Observations were made on living worms with intra vitam dyes, and on whole mounts, wax sections and ultrathin sections using transmission electron microscopy (TEM) to characterise the secretion from these glands and ascertain its mode of manufacture. The function of the glands remains unknown although it appears non-adhesive.

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