• ALGAE
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• v.22 no.4
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• pp.325-331
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• 2007

Cryptoglena pigra Ehrenberg from Korea was a photosynthetic euglenoid alga, which had typical characteristics of the Euglenales. The ultrastructure examination of C. pigra revealed certain features which were distinctly photosynthetic euglenoid: one U-shaped chloroplast with thylakoid membranes; two paramylon grains appressed to both sides of the chloroplast; eyespot associated with the chloroplast but not part of it. Three flagellar roots were associated with the two basal bodies. The four-membered dorsal root arose from the dorsal body and extended anteriorly following the reservoir membrane. At the base of the reservoir the dorsal band was nucleated by the dorsal root and it ran anteriorly between the reservoir membrane and eyespot. The dorsal band was continued with the microtubules of the canal and the pellicle. The singlet dorsal microtubules at the transition level arranged into doublets by a successive linkage of the existing adjacent microtubules, and the doublets rearranged into the cytoskeletal microtubules that were continuous with four microtubules in pellicles. Finally, the sixteen ridges gave rise to the pellicular ridges. The five to six-membered ventral root extended anteriorly into a cytoplasmic pocket through the reservoir and lined a cytoplasmic pocket.

• Journal of Life Science
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• v.27 no.6
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• pp.673-679
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• 2017

Microtubules are long rods in the cytoplasm of cells that plays a role in cell motility and intracellular transport. Microtubule-based transport by motor proteins is essential in intracellular transport. Kinesin 1 is a molecular motor protein that mediates the intracellular transport of various membranous vesicles, mRNAs, and proteins along microtubules. It is comprised of two heavy chains (KHCs, also called KIF5s) and two light chains (KLCs). KIF5s bear a motor domain in their amino (N)-terminal regions and interact with various cargoes through the cargo-binding domain in their carboxyl (C)-terminal regions. To identify proteins interacting with KIF5B, yeast two-hybrid screening was performed, and a specific interaction with the cytoplasmic linker protein 170 (CLIP-170), a plus end microtubule-binding protein, was found. The coiled-coil domain of CLIP-170 is essential for interactions with KIF5B in the yeast two-hybrid assay. CLIP-170 bound to the cargo-binding domain of KIF5B. Also, other KIF5s, KIF5A and KIF5C, interacted with CLIP-170 in the yeast two-hybrid assay. In addition, glutathione S-transferase (GST) pull-downs showed that KIF5s specifically interacted with CLIP-170. An antibody to KIF5B specifically co-immunoprecipitated CLIP-170 associated with KIF5B from mouse brain extracts. These results suggest that kinesin 1 motor protein may transport CLIP-170 in cells.

• Journal of Life Science
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• v.27 no.7
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• pp.840-848
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• 2017

Proper intracellular transport is essential for normal cell function. Intracellular transport is mediated by microtubule-dependent molecular motor proteins, as well as kinesin and cytoplasmic dynein, which move their cargo along long, microtubule tracks in cells. Kinesins are ATP-dependent plus-end-directed motor proteins in the intracellular transport of organelles, vesicles, RNA complexes, and protein complexes. The mislocalization of these different types of cargo has been linked to cell dysfunction and degeneration. The cargo transport of kinesins can be described by the following steps: binding to the appropriate cargo and/or adaptor proteins, activation of the kinesin's motility and movement along the microtubule, and the release of the cargo at the correct destination. Recently, several studies have revealed the mechanisms for the regulation of kinesin motor activity, including cargo loading and unloading. Intracellular cargo transport is also modulated by adaptor proteins, which link the kinesins to their cargo. The regulatory proteins, which include protein kinases and phosphatases, regulate kinesin motor activity directly through the phosphorylation or dephosphorylation of kinesins and indirectly through the modification of adaptor proteins, such as c-Jun NH-terminal kinase-interacting proteins, or of the microtubule network. These findings lay the groundwork for understanding how kinesins are differentially engaged in intracellular cargo transport. In addition, understanding the regulatory mechanisms of each kinesin is an area of key interest within cell biology and neurophysiology. In this study, we reviewed kinesins' regulation proteins and discuss how their regulation affects cargo recognition and transport.

• Applied Microscopy
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• v.7 no.1
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• pp.13-20
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• 1977

The ultrastructures of hemocytes of Acrida cinerea Thunberg were studied and 4 types of hemocytes were noticed; prohemocytes, plasmatocytes, granular cells and adipohemocytes. Prohemocytes were the smallest of all cell types with poor cytoplasmic organelles, such as endoplasmic reticulum, Golgi complexes, vacuoles and Iysosomes. Plasmatocytes were round or oval with many cytoplasmic processes, vacuoles, endoplasmic reticulum and even myelinated bodies. Granular cells were spindle-shaped or oval. In both cases, they are characterized by various granules. Adipohemocytes were very rich in lipid droplets and microtublles.

• Journal of Animal Science and Technology
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• v.50 no.6
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• pp.849-856
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• 2008

The present study was undertaken to investigate specific immune response of Rubus coreanus Miquel (raspberry) in pig spleen lymphocytes and gene expression induced by the extracts of raspberry using gene chip technology. The 70% ethyl alcohol extracts of raspberry were treated to pig spleen lymphocytes. The extracts of raspberry stimulated the proliferation of splenocytes and increased the population of CD3 & CD4 T-cells and B-cells in pig spleen lymphocytes. The extracts of raspberry improved immune response by increasing the viability of splenocytes. In microarray study we found eight genes were significantly up- regulated by the extracts of raspberry in pig splenocytes, including genes known to be involved in cell structure and immune response, particularly microtubule-associated protein 4, cytoplasmic dynein heavy chain, tumor necrosis factor alpha, lymphotoxin-beta receptor precursor. However, ten genes were down- regulated by the extracts of raspberry treatment.

• Journal of Life Science
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• v.33 no.7
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• pp.531-537
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• 2023

Intracellular and axonal transport is mediated by microtubule-dependent motor proteins, such as kinesins and cytoplasmic dynein. Kinesin moves along the microtubule to the positive end of the microtubule, while dynein moves to the negative end of the microtubule. Kinesin-1 was first identified as a kinesin superfamily protein (KIF) that functions in the intracellular transport of various cargoes, including organelles, neurotransmitter receptors, and mRNA-protein complexes, through interactions between the carboxyl (C)-terminal domain and the cargo. It interacts with other cargoes, but the adapter/scaffold proteins that mediate between kinesin-1 and the cargo have yet to be fully identified. In this study, a yeast two-hybrid screen was used to identify adapter proteins that interact with the C-terminal region of KIF5A. We found an association between the C-terminal region of KIF5A and the cyclin-dependent kinase 2-associated protein 1 (CDK2AP1), originally identified in malignant hamster oral keratinocytes. CDK2AP1 bound to the C-terminal region of KIF5A and did not interact with KIF3A (the motor of kinesin-2), KIF5B, KIF5C, and kinesin light chain 1 (KLC1). The C-terminal region of CDK2AP1 is essential for its interaction with KIF5A. When co-expressed in HEK-293T cells, CDK2AP1 and kinesin-1 co-immunoprecipitated and co-localized in the cells. These results suggest that the KIF5A-CDK2AP1 interaction serves as an adapter protein connecting kinesin-1 and the cargo when kinesin-1 transports cargo in cells.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1695-1701
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• 2002

The purposes of this study were to optimize the in vitro maturation (IVM) and culture (IVC) systems of rabbit oocytes. Cytoskeletal structures in the germinal vesicle stage (GV) and during IVM are also investigated. Ovaries were transported from local slaughterhouses and the cumulus-oocyte complexes (COCs) were collected from ovarian follicles (${\geq}1mm$). COCs were randomly allocated to TCM199-based medium ($T_1$, TCM-199) supplemented with $NaHCO_3$, glucose, sodium pyruvate and FSH ($T_2$), $T_2+E_2+LH$ ($T_3$), $T_3+FBS$ ($T_4$), or $T_1+E_2+LH+FSH+FBS$ ($T_5$), for IVM. In Experiment 1, COCs were retrieved from the follicles and 51 GV oocytes were fixed in the fixative (MTSB-XF) for nuclear and cytoplasmic examinations. In Experiment 2, progressive changes of both the nucleus and the cytoskeleton were examined at 0, 6, 16, and 20 h after IVM. Maturation (MR) and developmental rates were assessed in Experiment 3. Cytoplasmic microtubules (MT) were clearly observed in rabbit GV oocytes. To our knowledge, this is the first report that describes the appearance of MT structures in the GV stage ooplasm. Tremendous variations in cytoskeletal alterations were observed among treatments with the exception of the vitelline ring (VR), which is constantly visible and unchanged during maturation. Germinal vesicle breakdown (GVBD) does not occur at 6 h after onset of maturation culture. When the oocytes for IVM were collected within 2 h, results from Experiment 3 showed that rates of nuclear maturation were 42, 8, 42, 37 and 65% at 16 h of IVM for $T_1$ through $T_5$, respectively, in which $T_1$, $T_4$ and $T_5$ had significantly greater MR than those in other groups (p<0.05). Morula/blastocyst development after parthenogenetic activation ranged from 20 to 63% with significantly greater rates in $T_3$, $T_4$ and $T_5$ (p<0.05). These results suggested that oocytes recovered from slaughterhouse ovaries can be matured and parthenogenetically activated in vitro, but the MR remained low in this study. Addition of $E_2$ and LH in the medium may be beneficial for cytoplasmic maturation, but FBS exerts a nega- tive role in the subsequent development of parthenogenetic embryos when energy substrates are provided in the IVC media. More studies are required for improving the MR and further development of the GV stage rabbit oocytes.

• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.1-6
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• 2006

Mature spermatozoa of dark chub Zacco temmincki (Temminck and Schlegel), were examined under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The spermatozoa have a spherical, homogeneously electron-dense nucleus with an axial nuclear fossa containing two laterally oriented centrioles. The centrioles, which are arranged at about a $120^{\circ}$ angle to each other, have the 9+2 microtubule structure typical of flagella. The mature spermatozoon is of the primitive anacrosomal aquasperm type. The nuclear envelope is strongly undulated and contains nuclear vacuoles of different sizes and positions. The midpiece contains six or more mitochondria and encircles the basal body of the flagellum with an axoneme covered by the plasma membrane. Cytoplasmic vesicles lie between the axonemal doublets and the plasma membrane, and encircle the anterior part of the tail. The plasma membrane of the flagellum extends laterally and forms a pair of side fins. The species showed minor differences in number and structure of mitochondria, the angle between centrioles, and total length and occurrence of the fins. These characters, especially the side fins, appear to be apomorphic and useful for determining phylogenetic relationships at the genus or family level.

• Korean Journal of Microbiology
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• v.17 no.1
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• pp.1-15
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• 1979

Mycoplasma pneumoniae strain CL-s attached to broth-covered surfaces was examined sequentially during growth from single cells for morphologic and ultrastructural changes using several different electron microscopic techniques. Changes in morphology revealed both round and spindle shapes and observation of cell transitions suggested some type of morphological cycle. The round to-ovoid cells observed in the early stages of growth appeared to be viable, and morphologically and ultrastructurally different from the spherical fors which were produced during the latter stage of growth. The spindle segments were detected appeared to be structurally the same as the terminal cored structure seen in thin sections and may be a growing point or an attachment site of the cell. A tubular structure was observed in the core of the terminal structure and a microtubule-like element appeared to bridge between some spindle segments. A matrix sunstance was observed around single cells as well in the intercellular space of the colonies prepared by critical point metrical triple-layered cytoplasmic mermbranes, surfaces, of which appeared to be structurally different each other, were observed in young cells, whereas symmetrical and thicker membranes were seen in older cells. Small bodies were found in 4d or older cultures and did not appear to contain any internal structures or an easily detectable unit membrane.

• Journal of Korean Neurosurgical Society
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• v.30 no.8
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• pp.963-969
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• 2001

Objectives : Cord blood stem cells have been widely used as donor cells for bone marrow transplantation recently. These cells can give rise to a variety of hematopoietic lineages to repopulate the blood. Recent observations reveal that some bone marrow cells and bone marrow stromal cells(MSCs) can grow to become either neurons or glial cells. It is, however, unclear whether or not there exists stems cells which can differentiate into neurons in the blood during the early stages of postnatal life. Methods : Human cord blood stem cells were prepared from human placenta after full term delivery. To induce neuronal differentiation of stem cells, ${\beta}$-mercaptoethanol was treated. To confirm the neuro-glial characteristics of differentiated stem cells, immunocytochemical stain for NeuN, neurofilament, glial fibrillary acidic protein(GFAP), microtubule associated protein2(MAP2) was performed. RT-PCR was performed for detecting nestin mRNA and MAP2 mRNA. Results : We showed in this experiment that neuro-glial markers(NeuN, neurofilament, MAP2, GFAP) were expressed and axon-like cytoplasmic processes are elaborated in the cultured human cord blood stem cells prepared from new born placenta after full term delivery. Nestin mRNA was also detected in fresh cord blood monocytes. Conclusions : These results suggest that human cord blood derived stem cells may be potential sources of neurons in early postnatal life.