Ultrastructure of the egg of Coquillettidia venezuelensis (Theobald) (Diptera: Culicidae)

Zootaxa ◽  
2020 ◽  
Vol 4894 (3) ◽  
pp. 432-436
Author(s):  
CECILIA FERREIRA DE MELLO ◽  
JERONIMO ALENCAR
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Central Region ◽  
Outer Margin ◽  
Anterior Region ◽  
Width Ratio ◽  
Ultrastructural Characteristics ◽  
Scanning Electron

This study examined the ultrastructural characteristics of the egg of Coquillettidia venezuelensis (Theobald) (Diptera: Culicidae) with the aid of scanning electron microscopy. The eggs are elliptical and blackish, measuring on average 525.3 ± 12.8 μm in length and 94.9 ± 5.14 μm in width, with a length to width ratio of 5.54 ± 0.18. The anterior region of the egg is tubuliform, with a well-developed micropylar collar measuring approximately 2.54 ± 0.33 μm in thickness, the inner side of which is uniformly and deeply excavated, with a depression around the outer margin of the micropylar disc, which has a diameter of 29.4 ± 1.7 μm, an area of 234.4 μm2 ± 401.3 μm2 and a slightly elevated central region measuring 1.7 ± 0.5 μm in diameter that bears the central micropyle. 

Observations on North American Gomphoneis. III. Gomphoneis septa comb.nov.

1986 ◽  
Vol 64 (11) ◽  
pp. 2764-2768 ◽  
Author(s):  
J. P. Kociolek ◽  
E. F. Stoermer ◽  
L. L. Bahls
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
North American ◽  
Size Range ◽  
Taxonomic Position ◽  
Apical Pore ◽  
Close Relationship ◽  
Ultrastructural Characteristics ◽  
Scanning Electron

The valvar ultrastructure of the diatom Gomphonema septum Mogh. was investigated with scanning electron microscopy and is discussed with regard to the taxonomic position of this species. Ultrastructural features include striae composed of double rows of puncta, presence of a narrow axial plate which is responsible for the image of longitudinal lines, and apical pore fields composed of pores dissimilar in appearance from the puncta. These and other ultrastructural characteristics point to a close relationship between G. septum and members of the genus Gomphoneis. A transfer of Gomphonema septum to Gomphoneis is proposed. Information supplemental to previous observations on the size range and variability of this species is presented.

Gomphonema bicepiformis sp. nov., a new diatom species (Bacillariophyta) from a stream in Zhejiang, China

Phytotaxa ◽  
2018 ◽  
Vol 375 (4) ◽  
pp. 274 ◽  
Author(s):  
WEI ZHANG ◽  
GUANGXIA SHANG ◽  
JHONE PATRICK KOCIOLEK ◽  
LIQING WANG ◽  
HONGXIN TAN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Central Region ◽  
Zhejiang Province ◽  
Clean Water ◽  
Diatom Species ◽  
Freshwater Diatoms ◽  
Scanning Electron

During a survey of freshwater diatoms from Shibadukeng stream in the Xianju County, Zhejiang Province, China, a new gomphonemoid species, Gomphonema bicepiformis sp. nov. has been recorded. The new species is diagnosed from all others in the genus based on morphology as observed with both light and scanning electron microscopy. Valves of Gomphonema bicepiformis are lanceolate with a gibbous central region. The headpole is broadly rounded, clearly capitate and the footpole is also broadly rounded, capitate. The axial area is wide, lanceolate-rhombic, broad at mid-valve, reaching 3/4 of the total breadth. There are circular to irregularly-shaped depressions in the axial area on the exterior of the valve surface often appearing as light spots in LM. The new species was compared with G. biceps, G. obstipum, G. manubrium, G. pyrenaicum, G. guayabense and G. nipponica, all of which resemble Gomphonema bicepiformis in outline, but differ from the new species in specific details of size, striae density, and extent of the axial area. This species occurs in relatively low conductivity and clean water in Zhejiang, China.

Light and Electron Microscopic Observations in Atherosclerotic Rabbits following Experimental Transluminal Angioplasty

1987 ◽  
Vol 28 (3) ◽  
pp. 323-328 ◽  
Author(s):  
Y. Korogi ◽  
M. Takahashi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transluminal Angioplasty ◽  
Width Ratio ◽  
Electron Microscopic ◽  
Atherosclerotic Lesions ◽  
The Media ◽  
Histologic Changes ◽  
Percutaneous Transluminal ◽  
Scanning Electron

Light and scanning electron microscopy were used to assess the morphologic changes in atherosclerotic lesions in rabbits following percutaneous transluminal angioplasty. Histologic changes observed by light microscopy, i.e. fracture or separation of the plaque and overdistension of the media, were correlated with different balloon sizes. In atherosclerotic rabbits, progressive changes were observed in the vessel wall with increasing size of the balloon. Scanning electron microscopy showed denudation of the endothelial cells, exposure of the subintimal layer, and adhesion of the platelets. In addition, compression of the atheroma, circumferential endothelial rupture, flattening of the intimal fold, and undulation of the intimal fold were observed. Morphometric analysis of histologic sections of the dilated and non-dilated aortas disclosed significant differences in the thickness to width ratio of the plaque. These findings demonstrated that compression of the atherosclerotic plaque could occur.

Mucosal lesions in the rat associated with the attachment ofMoniliformis(Acanthocephala)

1983 ◽  
Vol 57 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Jean Martin ◽  
D. W. T. Crompton ◽  
Aruna Singhvi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Goblet Cells ◽  
Intestinal Wall ◽  
Anterior Region ◽  
Mucosal Tissue ◽  
Mucosal Lesions ◽  
Scanning Electron

ABSTRACTBy means of scanning electron microscopy, aspects of the attachment ofMoniliformis dubius(Acanthocephala) to the intestinal wall of the rat are described together with various changes in the structure and form of the mucosa. Attachment of the parasite results in the formation of a distinct pit around the everted proboscis and a crater around the neck. Contact between the anterior region of the trunk of the worm and the intestine of the host appears to lead to villous fusion so that characteristic grooves are formed in the mucosal tissue. Evidence was also obtained to suggest that host goblet cells may become exhausted during the course of an infection withMoniliformis.

Description of the egg of Hulecoeteomyia koreica (Edwards) (Diptera: Culicidae) using scanning electron microscopy

Zootaxa ◽  
2018 ◽  
Vol 4442 (1) ◽  
pp. 194-200
Author(s):  
CARLOS BRISOLA MARCONDES ◽  
CECÍLIA FERREIRA DE MELLO ◽  
AMANDA QUEIROZ BASTOS ◽  
FABRIZIO MONTARSI ◽  
JERONIMO ALENCAR ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mosquito Species ◽  
Anterior Region ◽  
Aedes Koreicus ◽  
Invasive Mosquito ◽  
Scanning Electron

The egg of Hulecoeteomyia koreica (Edwards) [=Aedes koreicus (Edwards)], an invasive mosquito in Europe, is described from material obtained in Italy. Eggs are cigar-shaped and tapered posteriorly. They are 667.5 ±47.27 µm in length, and the width posteriorly, in the middle and near the micropyle is, respectively, 113.18 ±10.07, 182.5 ±26.92 and 142.25 ±13.85µm. The outer chorion has groups of tubercles, 3 or 4 in an irregular row in the anterior region and 4–6 irregularly dispersed in cavities surrounded by a covering similar to a membrane. The micropyle is surrounded by an irregular collar, and groups of tubercles are less defined in this region. This pattern is different from the egg described for any other mosquito species. 

Micromorphological and ultrastructural description of spermatozoa from squirrel monkeys (Saimiri collinsi Osgood, 1916)

Zygote ◽  
2020 ◽  
Vol 28 (3) ◽  
pp. 203-207
Author(s):  
Danuza L. Leão ◽  
Wlaisa V. Sampaio ◽  
Patrícia C. Sousa ◽  
Arlindo A.A. Moura ◽  
Irma C. Oskam ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Male Fertility ◽  
Sperm Morphology ◽  
Squirrel Monkeys ◽  
Biotechnology Research ◽  
Transmission Electron ◽  
Middle Piece ◽  
Ultrastructural Characteristics ◽  
Scanning Electron

SummarySaimiri collinsi is used as an animal model in biotechnology research for conservation of species from the genus Saimiri. However, the development of biotechnologies depends on a proper knowledge of the sperm morphology to understand the basic aspects of sperm physiology, as potential male fertility depends on different cellular sperm structures. With this purpose, this study characterized the micromorphological and ultrastructural characteristics of squirrel monkeys (Saimiri collinsi) sperm using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM electromyography revealed that a normal Saimiri collinsi sperm measures 71.7 ± 0.7 μm with lateral tail insertion, a paddle-shaped flattened head and an acrosome occupying most of the head. TEM also showed that the middle piece is characterized by a central 9 + 2 microtubule axoneme surrounded by nine dense fibres, and that the mitochondria were juxtaposed, forming the mitochondrial sheath. Here we provide the first micromorphological and ultrastructure description of S. collinsi sperm.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

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).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Sign in / Sign up

Export Citation Format

Share Document