• The Korean Journal of Malacology
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• v.27 no.1
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• pp.69-76
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• 2011

Gill morphology and ultrastructure of the spiny top shell, Batillus cornutus were described using light and electron microscopy (SEM and TEM). The spiny top shell, Batillus cornutus has bipectinate gill. The epithelial layer of gill filament was simple and composed of columnar epithelium, ciliated cell, mitochondria-rich cell and secretory cell. Microvilli were well-developed on the free surface of columnar epithelial cell. The epithelial cells are connected to the neighboring cells with intercelluar junctions at the apico-lateral surface. The cilia and microvilli were commonly observed on the free surface of ciliated cell. Tubular mitochondria appeared in the apical cytoplasm, and connected ciliary rootlet. Mitochondria-rich cells contained a oval-shaped nucleus in the basal area. And majority of cytoplasm was occupied by well-developed mitochondria. Result of AB-PAS (pH 2.5) and AF-AB reaction showed that secretory cells contained mainly acidic carboxylated mucosubstances. Secretory cells are unicellular glands and can be divided into four types (A, B, C and D) depending on the cell shape and ultrastructure of secretory granules.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.1
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• pp.71-75
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• 2006

The aim of this study was to analyze the surface ultrastructure of RGP contact lenses post-use The RGP contact lenses, to investigate, were selected after one month, six months and one year of wear by the subjects. The anterior and posterior surfaces of these RGP contact lenses were inspected by a scanning electron microscope. The results were the following: 1. After one month of RGP contact lens use the anterior and posterior surfaces appeared clean and clear as originally. 2. After six months the anterior surface had several scars, dips, cracks and scratches. Upon the posterior surface appeared several foreign bodies and microorganisms. 3. After one year there was large scale damage and many foreign bodies were observed. Therefore, extended use of RGP contact lenses has shown increasing physical damage and extensive foreign body accumulation upon the ultrastructure of the lens surface.

• Applied Microscopy
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• v.17 no.2
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• pp.55-71
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• 1987

To investigate the effects of lead on the electron transport system and ultrastructure of mouse kidney mitochondria, various lead acetate concentrations were treated in vitro and respiration rate, enzyme activities were measured. Ultrastructural changes at state IV respiration were also observed. To compare with in vivo experiments, mouse were injected intraperitoneally of 100 mg lead acetate per kg body weight and state IV respiration rate and enzyme activities were measured. Ultrastructure of renal proximal tubular cells were also observed. In in vitro treatement, decreased state IV respiration, decreased enzyme activities, ruptured membranes and inhibition of condensed to orthodox transformation were observed. In in vivo treatment, decreased state IV respiration and decreased enzyme activities were observed after 24 hrs of i.p. injection. Cytochrome c oxidase activity showed twice the inhibition compared to NADH-CoQ reductase activity at 24 hrs. Continuous decreased state IV respiration was observed after 48 and 72 hrs of injection, however, the enzyme activities were increased to control level. Lead-protein complex which probably inhibits the toxic effects of lead appeared. To conclude, dominant effect of lead on the electron transport system appeared at cytochrome c oxidase activity, and the increased enzyme activities may be a result of appearance of lead-protein complex.

• Animal Systematics, Evolution and Diversity
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• v.12 no.3
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• pp.253-264
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• 1996

The ultrastructure of spermatozoa in urodeles and primitive anurans was examined and compared. The spermatozoa of urodeles are characterized by seven plesiomorphies in subacrosomal cone, endounclear canal. perforatorium, ring, marginal filament, undulating membrane and tail axis. Most primitive anuran spermatozoa have no marginal filament, subacrosomal cone and ring structure with the exception of having the subacrosomal cone in Ascaphus and the ring in Discohlossus as compared with those of urodeles. Persistence of the subacrosomal cone and the ring structure is typical in most urodeles and is further linked with the primitive anurans. Therefore, these characters are regarded as symplesiomorphies in urodeles and primitive anurans. The organization of sperm tail, endounclear canal and perforatorium indicates a close phylogenetic relationship between urodeles and the primitives anurans.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.163-166
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• 2008

The spermatozoal ultrastructure of Acheilognathus yamatsutae was studied using transmission electron microscopy. The mature spermatozoa are similar to those of other cyprinids as follows: a spherical nucleus with a shallow nuclear fossa, a short midpiece containing mitochondria and a long flagellum. However, there are some differences from other cyprinids in the orientation and position of the centrioles, the number of mitochondria, and the structure of vesicles. The position of the proximal centriole was of two types: one located on the side of nucleus decline, the other situated on the opposite side.

• Parasites, Hosts and Diseases
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• v.50 no.2
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• pp.177-180
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• 2012

Cercaria caribbea LVIII Cable, 1963 (Digenea: Cyathocotylidae) was detected from a brackish water gastropod species (Cerithideopsilla cingulata) in a coatal area of Shinan-gun, Jeollanam-do (Province), the Republic of Korea, and its surface ultrastructure was studied using a scanning electron microscope. The cercariae were found freely swimming or enveloped within daughter sporocysts when the snail host was mechanically broken. They were morphologically characterized by a linguiform and ventrally concave body, a long and bifurcated tail, and the presence of a holdfast (=tribocytic) organ posterior to the ventral sucker. On the whole ventral and dorsal surfaces, peg-like tegumental spines were densely distributed. Around the oral sucker, several sensory papillae, each with a short cilium, were distributed, and on the tail, sensory papillae, each with an extensively long cilium, were observed. This is the first record describing a cyathocotylid cercaria from a brackish water gastropod in the Republic of Korea.

• Applied Microscopy
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• v.25 no.4
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• pp.9-16
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• 1995

Ultrastructure of stemmata(larval eye) of 5th-instar larval in cabbage butterfly, Pieris rapae L, was morphologically investigated with light microscope, scanning electron microscope and transmission electron microscope Six stemmata are on each side of the head. Stemmata V and VI have a Y-shaped sulcus on the surface of their corneal lenses, the others have a columnar shaped process and smooth globular surface. The visual type of stemmata is resembled a single ommatidium of compound eye. The dioptric apparatus are a biconvex shaped cornea and crystalline cone. As a photoreceptor, each stemmata consists of 7 retinular cells arranged into 2 tiers. The first ceil tier of 3 distal retinular cells has formed a V-shaped cup rhabdome and the second cell tier of 4 basal retinular cells has formed a H-shaped fused rhabdome. Each retinular cell filled with pigment granules and contained multivesiclular bodies, coated vesicle and common organelles. The peripheral parts of retinular cells are enveloped by neuroglia cells and retinular cells are surrounded by 3 corneagenous cells. The distal portions of the 3 corneagenous cells contact each other, but the Y-shaped stemmata is separated from each other immediately under the cornea. The 7 axons from each stemma congregate into a bundle and each 7-axon group joins to form a stemmatal nerve, consisting of 42 retinular axons.

• Applied Microscopy
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• v.25 no.3
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• pp.1-19
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• 1995

The present study was performed to clarify the effect of vagus nerve stimulation on the enterochromaffin(EC) cells in the body of the stomach, the first part of the duodenum and the ceceum of rats by using routine electron microscopy and immunogold labelling. The changes in the ultrastructure and in the labelling density of the gold particles of the EC cells were investigated after vagus nerve stimulation. The vagus nerve was electrically stimulated with a square wave pulse generator for a duration of 5 minutes each, a total of 8 times at 2 minute intervals. Immunogold labelling demonstrated that the epithelial serotonin immunoreactive cells of the gastrointestinal tract are EC cells containing characteristic pleomorphic granules. Immunocytochemically labelled gold particles were largely concentrated in the dense matrix of the granules of the EC cell, and the labelling density of the gold particles considerably increased after the vagus nerve stimulation. Except for a slight activation of Golgi complexes, no remarkable changes in the ultrastructures of the EC cells were noted after the vagus nerve stimulation. The above results suggest that vagus nerve stimulation may activate serotonin biosynthesis in EC cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.157-162
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• 2003

Ultrastructure of germ cell during gametogenesis of surf clam, Spisula sachalinensis were investigated by electron microscopic observations. Oogonia are oval in shape and 5-6 ${\mu}m$ in diameter. They contain a large nucleus and have several mitochondria in the cytoplasm. Vitellogenic oocytes grew attached by a stalk to the germinal epithelium in the ovarian sac and their cytoplasm contained many yolk granules, lipid granules and mitochondria. Mature oocytes measuring 50-60 ${\mu}m$ in diameter have a nucleus containing an electron dense nucleolus, and a lots of yolk granules, lipid granules, mitochondria, rough endoplasmic reticulum and cortical granules were present in the cytoplasm. The surface of the plasma membrane in mature oocytes was formed of microvilli approximately 1.5 ${\mu}m$ long and enveloped in the vitelline layer. Spematogonia are oval in shape and about 5 ${\mu}m$ in diameter. Sprmatogonia develop into spermatocyte, spermatid and spermatozoon. The spermatozoon consisted of the head, midpiece and tail. The sperm head with diameter of about 1.5 ${\mu}m$ was ovoid, and contained the nucleus which consisted of acrosome. The four mitochondria encircled the centrosome in midpiece. The flagellum measuring about 40 ${\mu}m$ long had the classical 9+2 axoneme structure.

• Applied Microscopy
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• v.40 no.4
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• pp.253-259
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• 2010

The ultrastructure of sperms in testes of the pond smelt (Hypomesus nipponensis) was investigated using electron microscopes. The whitish testis was located between swim bladder and intestine. Especially, the left testis was larger than the right testis. The sperm was approximately $26\;{\mu}m$ in length. The sperm had an oval head and the acrosome was not found. The nucleus was about 400 nm in diameter and chromatin was incompletely condensed. The nuclear fossa deeply formed in sperm head and two centrioles were located in the fossa. The mitochondrium was observed only one in midpiece of the sperm and a motile flagellum consisted of an axoneme with a typical 9+2 pattern of microtubule. Also, the tail of the sperm has axonemal fins.