• The Korean Journal of Malacology
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• v.27 no.1
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• pp.55-65
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• 2011

Some characteristics of germ cell differntiations during spermiogenesis and mature sperm ultrastructure in male Phacosoma japonicus were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of other species in the subclass Heterodonta. Morphologies of the sperm nucleus and the acrosome of this species are the cylindrical type and cap shape, respectively. The spermatozoon is approximately 45-50 ${\mu}m$ in length, including a long curved sperm nucleus (about $3.70{\mu}m$ long with 45 $^{\circ}$ of the angle of the nucleus, an acrosome (about $0.55{\mu}m$ in length), and tail flagellum (about 42-$47{\mu}m$)The axoneme of the sperm tail shows a 9+2 structure. As some characteristics of the acrosomal vesicle structures, the basal and lateral parts of basal rings show electron opaque part (region), while the anterior apex part of the acrosomal vesicle shows electron lucent part (region). These characteristics of the acrosomal vesicle were found in the family Veneridae and other several families in the subclass Heterodonta. These common characteristics of the acrosomal vesicle in the subclass Heterodonta can be used for phylogenetic and systematic analysis as a taxonomic key or a significant tool. The number of mitochondria in the sperm midpiece of this species are four, as one of common characteristics appear in most species in the family Veneridae and other families in the subclass Heterodonta. However, exceptionally, only three species in Veneridae of the subclass Heterodonta contain 5 mitochondria. The number of mitochondria in the sperm midpiece can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

• The Korean Journal of Malacology
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• v.28 no.2
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• pp.165-174
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• 2012

The morphology and taxonomic values of the sperm in male Chlamys (Swiftopecten) swiftii were investigated by transmission electron microscope observations. The morphologies and ultrastructures of the sperm nucleus and the acrosome of this species are the vase type and long cone shape, respectively. Spermatozoa are approximately $45-50{\mu}m$ long including a sperm nucleus (approximately $2.60{\mu}m$ long), an acrosome (about $0.63{\mu}m$ long), and a tail flagellum (approximately $44-47{\mu}m$ in long). The axoneme of the sperm tail shows a 9+2 structure. In this study, the right and left basal rings in the acrosomal vesicle of this species show electron opaque part (region), and also the anterior apex part of the acrosomal vesicle shows electron opaque part (region). These characteristics of the acrosomal vesicle were found in Pectinidae and other several families in subclass Pteriomorphia. The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appear in most species in Pectinidae in subclass Pteriomorphia. In addition, the satellite fibres are found near the distal centriole of this species, as have been reported in other species of Pectinidae in subclass Pteriomorphia. Accordingly, structutral characteristics which are found in the acrosomal vesicle, four mitochondria in the sperm midpiece and the appearance of the satellite fibers near the distal centriole of C. (S.) swiftii in Pectinidae (subclass Pteriomorphia), can be employed for phylogenetic and taxonomic analyses as taxonomic key or a significant tool.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.667-674
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• 2007

Phase behavior for the mixed aqueous surfactant systems of cationic octadecyl trimethyl ammonium chloride (OTAC)/anionic ammonium dodecyl sulfate (ADS)/water was examined. Below the total surfactant concentrations of 1.5 m molal, mixed micelles were formed. At the total surfactant concentrations higher than 1.5 m molal, there appeared a region where mixed micelles and vesicles coexist. As the surfactant concentration increased, the systems looked very turbid and much more vesicles were observed. The vesicles were spontaneously formed in this system and their existence was observed by negative-staining transmission electron microscopy (TEM), small-angle neutron scattering (SANS) and encapsulation efficiency of dye. The vesicle region was where the molar fraction α of ADS to the total mixed surfactant was from 0.1 to 0.7 and the total surfactant concentration was above 5 × 10-4 molality. The size and structure of the vesicles were determined from the TEM microphotographs and the SANS data. Their diameter ranged from 450 nm to 120μm and decreased with increasing total surfactant concentration. The lamellar thickness also decreased from 15 nm to 5 nm with increasing surfactant concentration and this may be responsible for the decrease in vesicle size with the surfactant concentration. The stability of vesicles was examined by UV spectroscopy and zeta potentiometry. The vesicles displayed long-term stability, as UV absorbance spectra remained unchanged over two months. The zeta potentials of the vesicles were large in magnitude (40-70 mV) and the observed longterm stability of the vesicles may be attributed to such high ζ potentials.

• Korean Journal of Animal Reproduction
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• v.20 no.3
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• pp.343-351
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• 1996

The objectives of this study are to determine cortical granule distribution during in vitro maturation, parthenogenetic activation and in vitro fertilization of oocytes, and to investigate effects of microfilament inhibitor on the cortical granule distribution during in vitro maturation and fertilization of oocytes in the pig, The corti-cal granule distribution were imaged with fluor-escent labeled lectin under laser scanning confocal microscope or detected by transmission electron microscope. At germinal vesicle stage, cortical granule organelles were located around the cell cortex and were present as a relatively thick area on the oolema. Microfilaments were also observed in a thick uniform area around the cell cortex. Following germinal vesicle break down,microfilaments concentrated to the condensed chromatin and cortical granules were observed in the cortex. Treatment with cytochalasin B inhibited microfilament polymerization and prevented movement of cortical granules to the cortex. Cortical granule exudate following sperm penetration was evenly distributed in the entire perivitelline space. Therefore, these results suggested that the microfilament assembly is involved in the distribution, movement and exocytosis of cortical granules during maturation and fertilization of porcine oocytes. (Key words cortical granule, porcine, maturation, fertilization).

• The Korean Journal of Malacology
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• v.27 no.2
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• pp.121-129
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• 2011

The ultrastructural characteristics of germ cell development during spermatogenesis and mature sperm morphology of in male Scapharca subcrenata were investigated by transmission electron microscope observation. Spermatogonia are located nearest the outer wall of the acinus, while spermatocytes and spermatids are positioned near the accessory cells. The accessory cells, which is in close contact with developing germ cells, contained a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in supplying of the nutrients for germ cell development. The morphologies of the sperm nucleus and the acrosome of this species are the oval shape and cone shape, respectively. Spermatozoa are approximately 45-$50{\mu}m$ in length including a sperm nucleus (about $1.30{\mu}m$ in length), an acrosome (about $0.59{\mu}m$ in length), and tail flagellum (about 43-$47{\mu}m$). The axoneme of the sperm tail shows a 9 + 2 structure. As some characteristics of the acrosomal vesicle structures, the right and left basal rings show electron opaque part (region), and also the anterior apex part of the acrosomal vesicle shows electron opaque part (region). These characteristics of the acrosomal vesicle were found in Acinidae and other several families in subclass Pteriomorphia. These common characteristics of the acrosomal vesicle in subclass Pteriomorphia can be used for phylogenetic and taxonomic analysis as a taxonomic key or a significant tool. The number of mitochondria in the midpiece of the sperm of this species are five, as one of common characteristics appear in most species in Arcidae and other families in subclass Pteriomorphia. The acrosomal vesicles of Arcidae species do not contain the axial rod and several transverse bands in acrosome, unlkely as seen in Ostreidae species in subclass Pteriomorphia, These characteristics can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

• Genomics & Informatics
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• v.19 no.4
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• pp.39.1-39.8
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• 2021

Tamoxifen (TAM) is an anticancer drug used to treat estrogen receptor (ER)-positive breast cancer. However, its ER-independent cytotoxic and antifungal activities have prompted debates on its mechanism of action. To achieve a better understanding of the ER-independent antifungal action mechanisms of TAM, we systematically identified TAM-sensitive genes through microarray screening of the heterozygous gene deletion library in fission yeast (Schizosaccharomyces pombe). Secondary confirmation was followed by a spotting assay, finally yielding 13 TAM-sensitive genes under the drug-induced haploinsufficient condition. For these 13 TAM-sensitive genes, we conducted a comparative analysis of their Gene Ontology (GO) 'biological process' terms identified from other genome-wide screenings of the budding yeast deletion library and the MCF7 breast cancer cell line. Several TAM-sensitive genes overlapped between the yeast strains and MCF7 in GO terms including 'cell cycle' (cdc2, rik1, pas1, and leo1), 'signaling' (sck2, oga1, and cki3), and 'vesicle-mediated transport' (SPCC126.08c, vps54, sec72, and tvp15), suggesting their roles in the ER-independent cytotoxic effects of TAM. We recently reported that the cki3 gene with the 'signaling' GO term was related to the ER-independent antifungal action mechanisms of TAM in yeast. In this study, we report that haploinsufficiency of the essential vps54 gene, which encodes the GARP complex subunit, significantly aggravated TAM sensitivity and led to an enlarged vesicle structure in comparison with the SP286 control strain. These results strongly suggest that the vesicle-mediated transport process might be another action mechanism of the ER-independent antifungal or cytotoxic effects of TAM.

• Development and Reproduction
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• v.17 no.2
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• pp.141-147
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• 2013

Keeping the intact germinal vesicle (GV) is essential for maintaining the capacity of mammals including human. It is maintained by very complex procedures along with folliculogenesis and is a critical step for getting competent oocyte. So far, a few mechanisms involved in folliculogenesis are known but GV arrest mechanisms are largely unrevealed. Cyclic AMP, a adenosine derived substance, have been used as inhibitor of germinal vesicle breakdown as a putative oocyte maturation inhibitor. In this study, we examined the potency of adenosine as GV maintainer and a possible signaling mediator for that. A1, A2b, and A3 were detected in cumulus cells of cumulus enclosed-oocyte (CEO). Intact of germinal vesicle was not kept like in follicle but the spontaneous maturation was inhibited by exogenous adenosine. It is inhibited with concentration dependent manners. Intracellular calcium level of cumulus was extensively increased after adenosine treatment. Based on these results it is suggested that one of the pathway for GV arrest by adenosine and its receptors is calcium mediated signaling pathway in CEO.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.169-173
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• 2010

Correlations between cumulus cells and germinal vesicle (GV) chromatin configuration were examined in porcine oocytes. Cumulus-oocyte complexes (COCs) were collected from 2~6 mm follicles and divided into three categories according to cumulus cell morphology. "A" group was compacted COCs with more than three cumulus cell layers. "B" group was COCs with less cumulus cell layers than "A" group. "C" group was COCs with one or less layer of cumulus cells. Cumulus cells were removed 0.1% hyaluronidase, and denuded oocytes were stained with Hoechst 33342. GV chromatin configuration was classified into GV-Con and GV-Dis. GV-Con meant that a nucleus was surrounded by condensed chromatin in a ring. GV-Dis meant that filamentous chromatin clumps were distributed in nucleus. The proportion (80.2%) of GV-Con in "A" group was significantly higher than "B" (62.0%) or "C" (44.9%). The proportion (55.1%) of GV-Dis in "C" group was significantly higher than "A" (19.8%) or "B" (38.0%). The meiotic competence of COCs was examined after 44 h culture. The proportion (90.0%) of oocytes reaching to metaphase II (M-II) in "A" group was significantly higher than "B" (76.5%) or "C" (45.5%). In conclusion, oocytes with good quality cumulus cell layers are synchronized early GV stage, and early GV stage is important for meiotic competence in pigs.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.273-282
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• 1987

가토 신피질에서 분리한 brush border membrane (BBM)과 basolateral membrane vesicle (BLM)에서 유기 음이온인 p-aminohippuric acid (PAH)와 유기 양이온인 tetraethylammonium (TEA)의 이동에 대한 동력학적 분석을 하였다. BLM에서 PAH에 대한 Km과 Vmax값은 각각 $0.34{\pm}0.02\;mM$과 $0.22{\pm}0.07\;nmol/mg\;protein/20s$였으며 BBM에서 각 값은 $8.46{\pm}0.57\;mM$과 $4.43{\pm}0.40\;nmol/mg\;protein/20s$였다. BLM에서 용액내 Na의 제거는 PAH에 대한 Km 값에는 영향없이 Vmax 값을 변화시켰다. BBM에서 TEA이동에 대한 Km과 Vmax 값은 각각 $0.55{\pm}0.15\;mM$과 $1.04{\pm}0.23\;nmol/mg\;protein/20s$였으며 BLM에서 각 값은 $0.46{\pm}0.04\;mM$과 $0.61{\pm}0.06\;nmol/mg\;protein/20s$였다. BLM에서 측정한 유기 이온들의 이동에 대한 Km 값이 신절편이나 분리된 tubule에서 보고된 값과 일치함을 보였으며 이러한 결과는 신세뇨관 세포막을 통한 유기 이온들의 이동 특성이 membrane vesicle을 분리하는 과정에서 변하지 않았음을 가르킨다.

• Fisheries and Aquatic Sciences
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• v.8 no.1
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• pp.17-26
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• 2005

The ultrastructure of germ cells during spermatogenesis and the structural changes in the epithelial cells of the seminal vesicle with testicular development in male Neptunea (Barbitonia) arthritica cumingii were investigated monthly based on electron microscopic and histologic observations. N. arthritica cumingii (Gastropod: Buccinidae) undergoes internal fertilization and possesses a modified type of spermatozoon, which is approximately 20$\mu$m long. The axoneme of the tail flagellum consists of nine peripheral pairs of microtubules and one central pair. Many spermatozoa occur in the acini of the testis in the ripe stage and are transported to the seminal vesicles in the accumulating phase. In males, the monthly gonadosomatic index began to increase in September and reached a maximum in February. Subsequently, it decreased rapidly after April. The testis of this species can be classified into four developmental stages: the active (August to September), ripe (October to July), copulation (April to July), and recovery (July to August) stages. Structural changes in the epithelial cells of the seminal vesicles of this species could be classified into three phases: (1) S-I (resting), (2) S-II (accumulating), and (3) S-III (spent) phases. The morphology and structure of the epithelial cells of the seminal vesicle differed in each phase; the cells were cuboidal, squamous, or columnar in the resting, accumulating, or spent phases, respectively.