• The Korean Journal of Mycology
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• v.40 no.4
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• pp.224-228
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• 2012

In order to screen interactor(s) of the Aspergillus nidulans ${\alpha}$-COP of COPI vesicle, we performed the yeast two hybrid screening by using the gene for A. nidulans ${\alpha}$-COP as a bait and identified ${\varepsilon}$-COP of the COPI vesicle as an interacting protein. The A. nidualns gene for the ${\varepsilon}$-COP was designated $aneA^+$ ($\underline{A.}$ $\underline{n}$idulans $\underline{e}$psi-lone-COP), which encoded 296 amino acid residues with high level of identity with orthologs from other fungi. Domain analyses with yeast two-hybrid system suggested that the interaction between ${\alpha}$-COP and ${\varepsilon}$-COP relied on the C-terminus of both proteins, and that the N-terminal WD domian of ${\alpha}$-COP and the TPR region of ${\varepsilon}$-COP were not essential but required for the enhancement of the interaction. These results indicate that the interaction mode between ${\alpha}$-COP and ${\varepsilon}$-COP of COPI vesicle is evolutionarily well conserved in eukaryotes.

• Applied Microscopy
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• v.32 no.1
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• pp.17-30
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• 2002

The retinae of Todarodes pacificus and Octopus minor are divided into four layers that are an outer segment, a rod base region, an inner segment, and a plexiform layer, respectively. The retina of Octopus minor is about $20{\mu}m$ thicker ($400{\sim}420{\mu}m$) than that of Todarodes pacificus ($385{\sim}400{\mu}m$). A retina is composed of visual cells and supporting cells. The microvilli of length $0.6{\sim}0.7{\mu}m$ are packed densely on top of the supporting cells of Octopus minor while they are not found in Todarodes pacificus. The visual cells and supporting cells have pigment granules that exclude light. In case of Todarodes pacificus, the pigment granules of the visual cell are larger ($2.0{\times}0.5{\mu}m$) than those of the supporting cell ($1.0{\times}0.3{\mu}m$). But, the sizes of both cells are similar in Octopus minor. In the upper portion of a visual cell, microvilli shaped like a comb are forming a rhabdome (diameter, 60 nm) of a hexagonal structure. The rhabdome consists of 4 rhabdomere and the total area of a rhabdom of Octopus minor is larger than that of Todarodes pacificus. The synaptosome constructing a plexiform layer in Todarodes pacificus are divided into two types, each of which possess electron dense-core vesicles and electron lucent vesicles, respectively. Octopus minor also has two types of synaptosomes but each type comprises a mixture of electron dense vesicles and electron lucent vesicles, and electron lucent vesicles only, respectively, which is different from the case of Todarodes pacificus.

• Journal of Life Science
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• v.26 no.1
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• pp.59-67
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• 2016

Platycodon grandiflorum A. De Candolle (Korean name, ‘Doraji’) is a perennial plant containing various triterpenoid saponins. The roots of this plant have traditionally been used as a food material in Korea. Here, we prepared a fermented P. grandiflorum extract (PG). Although it was previously reported that P. grandiflorum A. extract has a variety of physiological functionalities, including anti-inflammatory and anti-oxidant activities, little is known about its vascular functions. In this study, we executed a series of experiments to identify the effect of PG on endothelial cells. PG at a high concentration (100 μg/ml) was found to induce cell detachment, whereas PG at a low concentration (0.1 μg/ml) appeared to promote cell proliferation and migration in bovine aortic endothelial cells. The cell detachment induced by the high concentration was not associated with cell death, such as apoptosis, necrosis, and autophagy. In addition, we found that PG at the high concentration formed a small vesicular structure called an endothelial microparticle (EMP). The EMP was prepared by centrifugal fractionation and determined with flow cytometry and a microscope. Interestingly, PG-induced cell detachment was found to be mediated by EMP. We furthermore determined that PG at the low concentration activated Akt, a crucial cell-signaling molecule, and then controlled cell proliferation and migration. Overall, our findings suggest that PG at low doses maintains vascular stability by promoting endothelial cell proliferation, and enhances the efficacy of wound healing by cell proliferation and migration activity.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.405-416
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• 1995

The testis and the epididymis of sexually mature male bats were examined to investigate the process of spermiogenesis of Korean long-fingered bat (Miniopterus schreifersi fulignosus) using electron microscope. The ultrastructural findings were analysed on the basis of Lee's method (1992). Especially, we focused on the acrosome formation. The results are as follows: The spermiogenesis of the Korean long-fingered bat can be divided into ten phases on the basis of ultrastructural differentiation; three "Golgi" phases of early, mid and late stages, two "cap" and two "acrosome" phases respectively composed of early and late phases, one "maturation phase and two "spermiation" phases of early and late phases. The axoneme of sperm in the cauda epididymis is composed of nine outer dense fiber and a central singlet. The number 1, 5, 6, and 9 outer dense fibers are larger than others. In the Golgi phases, small vesicles are separated from Golgi vesicles and then appear to fuse into a large vesicle, and finally it contacd with the outerside of the nucleus. It suggests that proacrosomal material could be made in the cytoplasm before the Golgi vesicle formation and then it could be transferred into the Golgi vesicle and condensed more and more, and finally form acrosome, just as Lee;s suggestion (1992).m acrosome, just as Lee;s suggestion (1992).

• International Journal of Oral Biology
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• v.41 no.3
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• pp.133-139
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• 2016

The ultrastructural parameters related to synaptic release of endings which are presynaptic to tooth pulp afferent terminals (p-endings) were analyzed to understand the underlying mechanism for presynaptic modulation of tooth pulp afferents. Tooth pulp afferents were labelled by applying wheat-germ agglutinin conjugated horseradish peroxidase to the rat right lower incisor, whereafter electron microscopic morphometric analysis with serial section and reconstruction of p-endings in the trigeminal oral nucleus was performed. The results obtained from 15 p-endings presynaptic to 11 labeled tooth pulp afferent terminals were as follows. P-endings contained pleomorphic vesicles and made symmetrical synaptic contacts with labeled terminals. The p-endings showed small synaptic release-related ultrastructural parameters: volume, $0.82{\pm}0.45{\mu}m^3$ ($mean{\pm}SD$); surface area, $4.50{\pm}1.76{\mu}m^2$; mitochondrial volume, $0.15{\pm}0.07{\mu}m^3$; total apposed surface area, $0.69{\pm}0.24{\mu}m^2$; active zone area, $0.10{\pm}0.04{\mu}m^2$; total vesicle number, $1045{\pm}668.86$; and vesicle density, $1677{\pm}684/{\mu}m^2$. The volume of the p-endings showed strong positive correlation with the following parameters: surface area (r=0.97, P<0.01), mitochondrial volume (r=0.56, P<0.05), and total vesicle number (r=0.73, P<0.05). However, the volume of p-endings did not positively correlate or was very weakly correlated with the apposed surface area (r=-0.12, P=0.675) and active zone area (r=0.46, P=0.084). These results show that some synaptic release-related ultrastructural parameters of p-endings on the tooth pulp afferent terminals follow the "size principle" of Pierce and Mendell (1993) in the trigeminal nucleus oralis, but other parameters do not. Our findings may demonstrate a characteristic feature of synaptic release associated with p-endings.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.3
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• pp.155-168
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• 2004

Objective: Melatonin, which is secreted by pineal gland play an important role in the regulation of ovarian function via seasonal rhythm and sleep in most mammals. It also has a role in the protection of cells by removing toxic oxygen free radicals brought about by metabolism. In the present study, effects of melatonin on the mouse oocyte maturation were examined using two different culture conditions provided with 5% or 21% oxygen concentration. Material and Method: Immature mouse oocytes were obtained from the ovarian follicles of $3{\sim}4$ weeks old ICR strain mice intraperitoneally injected with 5 I.U. PMSG 44 hour before. Under stereomicroscope, morphologically healthy oocytes with distinct germinal vesicle (GV) were liberated from the graafian follicles and collected using mouth-controlled micropipette. They were then cultured for 17 hour at $37^{circ}C$, 5% $CO_2$ and 21% $O_2$ (95% air) or 5% $CO_2$, 5% $O_2$ and 90% $N_2$. New modified Hank's balanced salt solution (New MHBS) was used as a culture medium throughout the experiments. Effects of melatonin were examined at a concentration of $0.0001{\mu}M$, $0.01{\mu}M$ or $1.0{\mu}M$. For the prevention of spontaneous maturation of immature oocytes during culture, dibutyryl cyclic AMP (dbcAMP) and/or hypoxanthine were included in the medium. Results: Under 21% oxygen condition, oocytes cultured in the presence of $0.01{\mu}M$ melatonin showed a significantly higher maturation rates, in terms of germinal vesicle breakdown (95.0% vs 89.0%) and polar body formation (88.1% vs 75.4%), compared to those cultured with $0.0001{\mu}M$ or $1.0{\mu}M$ melatonin. However, no difference was observed in oocytes cultured under 5% oxygen whether they were treated with melatonin or not. In the presence of $0.01{\mu}M$ melatonin, oocytes either cultured under 21% or 5% oxygen exhibited no difference in the polar body formation (85.6% vs 86.7%). However, in the absence of melatonin, oocytes cultured under 21% oxygen exhibited lower polar body formation (74.7%). When oocytes were cultured in the presence of dbcAMP alone or with varying concentrations of melatonin, those treated with both compounds always showed better maturation, i.e., germinal vesicle breakdown and polar body formation, compared to those cultured with dbcAMP alone. At the same concentration of melatonin, however, oocytes exposed to 21% oxygen showed poor maturation than those to 5% oxygen. Similar results were obtained from the experiments using hypoxanthine instead of dbcAMP. Conclusion: Based upon these results, it is suggested that melatonin could enhance the meiotic maturation of mouse oocytes under 21% oxygen concentration, and release oocytes from the meiotic arrest by dbcAMP or hypoxanthine regardless of the concentration of oxygen, probably via the removal of oxygen free radicals.

• The Korean Journal of Malacology
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• v.26 no.3
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• pp.235-244
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• 2010

Ultrastructural characteristics of the testis and spermatogenesis of Crassostrea gigas were investigated by Transmission and Scanning Electron microscope observations. The testis is a diffuse organ consisting of branching acini containing differentiating germ cells in a variety of stages. The acinus is surrounded by an intermitent layer of myoepithelial cells andis divided into subcompartments that are partially separated by pleomorphic accessory cells which remain in close contact with germ cells until late stages of development. these accessory cells contain a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in the supplying of the nutrients for germ cell development, while any phenomena associated with phagocytosis of undischarged, residual sperms by lysosomes could be find in the cytoplasm of the accessory cells. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves. Mature spermatozoa consist of broad, cap-shaped acrosomal vesicle, subacrosomal material (containing axial rod embedded in a granular matrix), a oval nucleus showing deeply invaginated anteriorly, two triplet substructure centrioles surrounded by four spherical mitochondria, and satelite fibres appear to the distal centriole and plasma membrane. Spermatozoa of C. gigas resemble to those of other investigated ostreids. In particular, the anterior region of the acrosomal vesicle is transversely banded. It is assumed that differences in this acrosomal substructure are associated with the inability of fertilization between the genus Crassostrea and other genus species in Ostreidae. Therefore, we can use sperm morphology in the resolution of taxonomic relationships within the Ostreidea. The spermatozoon is approximately $42-47{\mu}m$ in length including an oval sperm nucleus (about $0.91{\mu}m$ in length), an acrosome (about $0.42{\mu}m$ in length) and tail flagellum ($40-45{\mu}m$). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9 + 2 structure. These morphological charateristics of acrosomal vesicle belong to the family Ostreidae in the subclass Pteriomorphia.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.241-241
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• 2004

본 연구는 발정주기에 따른 개의 미성숙난자의 체외배양 0시간째 핵의 발달단계를 비교ㆍ검토하였다. 발정주기가 다른 개의 난소를 적출 하여 항생제가 첨가된 38℃의 0.9% 생리식염수가 들어있는 보온병에 넣어 2시간 이내에 연구실로 운반하고 난소를 면도날로 세절하여 난포란을 회수하였고, 난구세포 제거 후 Chohan과 Hunter (2003) 방법에 준하여 10 ug/ml Hoechst 33342를 이용한 핵염색을 실시하여 핵의 모양을 판명하였다. 조사된 결과는 SAS 8.0 Package를 이용하여 통계분석을 실시하였다. (중략)

• Toxicological Research
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• v.8 no.1
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• pp.95-107
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• 1992

Basolateral and brush border membrance (BLM and BBM) vesicles of renal proximal tubules were prepared from adult male New Zealand White rabbits to develop an experimental for assessment of nephrotoxicity. PAH uptakes using BLMV, and glucose and leucine uptakes using BBMV were measured in the rabbits treated uranyl acetate. In addition, urinalysis and histopathological studies were performed to investigate the correlationship with the membrance vesicle uptakes.

• Journal of Plant Biology
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• v.33 no.4
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• pp.325-332
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• 1990

Light membrane vesicles were isolated from the zucchini hypocotyl by floatation on ficoll density gradients and the proteins were solubilized with Triton X100. Three ATP-hydrolyzing enzymes were partially purified by ion-exchange and gel filtration chromatography and isoelectric focusing. There are plasma membrane-type ATPase whose activity was inhibited by vanadate but not by nitrate, tonoplast-type ATPase which was sensitive to nitrate but insensitive to vanadate and one having a phosphatase activity with a pI value different from that of an acid phosphatase. A fraction was obtained after DEAE-ion-exchange chromatography crossreacting with polyclonal antibodies against Ca2+ -ATPase from human erythrocytes.