Light and electron microscope structural study of the zona radiata in the oocyte of zebrafish (Danio rerio)

Microscopy ◽  
2013 ◽  
Vol 62 (3) ◽  
pp. 377-382 ◽  
Author(s):  
E. F. Kaviani ◽  
N. Shabanipour ◽  
S. B. Mirnategh
Keyword(s):  
Electron Microscope ◽  
Structural Study ◽  
Danio Rerio ◽  
Zona Radiata

Fine structure of egg envelopes in some viviparous goodeid fishes, with comments on the relation of envelope thinness to viviparity

1993 ◽  
Vol 71 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Rüdiger Riehl ◽  
Hartmut Greven
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Mode Of Reproduction ◽  
Zona Radiata ◽  
Complex Envelope ◽  
Egg Envelope ◽  
Egg Envelopes

The egg envelope (zona radiata) of the full-grown oocytes before fertilization was examined by electron microscope in eight viviparous species of Goodeidae (Cyprinodontiformes) from the Mexican plateau. The egg envelope is composed of a homogeneous electron-dense zona radiata perforated mainly by oocyte microvilli. The thickness of the zona radiata ranged from 0.5 μm (Xenoophorus captivus) to 1.5 μm (Ameca splendens). Egg envelopes of Ataeniobius toweri and Ilyodon xantusi appeared to have two layers, tentatively described as a zona radiata interna and a zona radiata externa. The most complex envelope was observed in Girardinichthys multiradiatus, which showed a small filamentous zona radiata interna and an electron-dense zona radiata externa covered by an additional flocculent layer, which is probably the gelatinous coat found in many eggs. The egg envelope of Ameca splendens, Girardinichthys viviparus, and Xenotoca eiseni displayed short external processes resembling attaching filaments, which are known from eggs of substrate-spawning teleosts. The thickness and differentiation of the zona radiata in other viviparous teleosts are compared and discussed with reference to mode of reproduction.

The Ultra Structural Study of Blastema in Pinna Tissues of Rabbits with Transmission Electron Microscope

2008 ◽  
Vol 8 (6) ◽  
pp. 993-1000 ◽  
Author(s):  
Nasser Mahdavi Shahri ◽  
Fatemeh Naseri ◽  
Masoumeh Kheirabadi ◽  
Sakineh Babaie ◽  
Fereshteh Sadeghie Shakib ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Structural Study ◽  
Transmission Electron Microscope ◽  
Transmission Electron

scholarly journals Effects of Short-Term Exposure to Sublethal Concentrations of Silver Nanoparticles on Histopathology and Electron Microscope Ultrastructure of Zebrafish (Danio Rerio) Gills

2016 ◽  
Vol 10 (1) ◽  
pp. 15-20
Author(s):  
Borhan Mansouri ◽  
◽  
Seyed Ali Johari ◽  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Adverse Effects ◽  
Danio Rerio ◽  
Secondary Lamellae ◽  
Short Term Exposure ◽  
Gill Filaments ◽  
Hazardous Pollutants ◽  
Dose Dependent ◽  
Sublethal Concentrations

Background: The increasing use of nanomaterials and nanoproducts has increased the possibility of contamination of the environment, which may have adverse effects on different organisms. The aim of this study was to evaluate the effects of silver nanoparticles on histopathology and gill ultrastructure of zebrafish (Danio rerio) under laboratory conditions. Methods: Zebrafish were exposed to four concentrations of silver nanoparticles (0.0015, 0.00375, 0.0075, and 0.015 mg/l) for a period of 4 days. Gill ultrastructure and histopathological changes were studied using scanning electron microscope and haematoxylin - eosin staining. Results: Exposure to silver nanoparticles significantly (P < 0.001) increased the diameter of gill filaments and secondary lamellae, while silver nanoparticles significantly reduced the length of the secondary gills in zebrafish. Moreover, other changes such as vacuolization, dilated and clubbed tips, hyperplasia, edema, fusion, swelling of mucocytes, hypertrophy, and necrosis were observed. The effects of silver nanoparticles in zebrafish gills were dose dependent. Conclusion: Based on the adverse effects of AgNPs on zebrafish gills, silver nanoparticle solutions can be hazardous pollutants for the environment.

scholarly journals Synthesis and structural study of multiferroics in the Gd x Bi 1−x Cr 0.5 Fe 0.5 O 3 system (x=0.1, 0.2, 0.5)

2020 ◽  
Vol 130 (1) ◽  
pp. 81-87
Author(s):  
M.M. Mataev ◽  
◽  
N.B. Abisheva ◽  
Zh.Y. Tupsinova ◽  
M.R. Abdraymova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Nitric Acid ◽  
Scanning Electron Microscope ◽  
Phase Analysis ◽  
Structural Study ◽  
Single Phase ◽  
Synthesis Method ◽  
X Ray ◽  
Scanning Electron

The synthesis of compounds was carring out in the system of gadolinium chromite - ferrites doped with bismuth. The citrate-nitrate method was chosen as the synthesis method. An X-ray phase analysis was performed to study the formation of new phases. Based on the results of x-ray phase analysis, it was determined that the obtained compounds in the chromiteferrite system are crystallized in orthorhombic syngony with the Pbnm(62) spatial group. It is showing that when nitric acid is using as a precipitator, can be obtaining single-phase powders. In addition, the structure and parameters of elementary cells of synthesized chromite - ferrites were determining by x-ray phase analysis. The shapes and sizes of the resulting manganite powders determined by electron microscopy. According to the results of the scanning electron microscope, the powders of synthesized chromite-ferrites consist of crystals from 184.3 nm to 3.02 microns.

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