• Applied Microscopy
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• v.38 no.2
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• pp.97-105
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• 2008

The fine structural modification of the granulocytes between the molt and intermolt period were investigated by the transmission electron microscopy. The granular hemocytes of the spider Araneus ventricosus were composed of three subtypes: eosinophilic granulocytes (EGs), basophilic granulocytes (BGs) and cyanocytes. Both of the EGs and BGs have electron dense granules within their cytoplasms, however the granules of BGs are larger than those of EGs. During the molt period, some of the EGs have fine structural modification in their cell organelles including formation of phagosomes as a result of active phagocytosis. However, the BGs have no phagosomes, but electron densities of the granules are changed to lower states than the intermolt period. The cyanocyte is the biggest hemocyte among the granulocytes. They contain numerous hemocyanin crystals in the cytoplasm with some electron-lucent vacuoles. During the molt period, some of the cyanocytes are changed to irregular shapes. High magnification electron micrographs reveal that the lattice sub-structure of the hemocyanin crystals are very similar to those of microtubules, and each tubule is composed of approximately 20 filaments with fine fibrillar structure.

• The Korean Journal of Zoology
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• v.31 no.2
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• pp.122-132
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• 1988

Ultrastructure of the cutaneous granular glands and production of their secretory granules in the water toad, Bufo steinegeri Schmidt, are studied with light and electron microscopes. Cutaneous granular glands of the water toad have gland cavity in dermis and gland duct in epidermis. Each gland cavity of the granular glands is consisted of 3 types of cells which are inner glandular epithelial cells, outermost myoepithelial cells and another kind of epithelial cells near the gland duct. Characteristically, cytoplasms of the glandular epitelial cells appeared multinucleated masses without differentiation into cells. Poisonous secretory graules excreated by the merocrine secretion are basicafly composed of 2 kinds of granules which are electron dense granules and electron lucent granules. These granules are fused each other and forming compounded structures. According to the granular size and differentiated levels, they are subdivided into 4 types of granules. Synthesis of these secretory granules is occurred at the smooth endoplasmic reticulums of the glandular epithelial cells and limiting membranes of these granules are also originated from these cell organelles.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.12-21
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• 1990

When a piece of the dorsal skin(cat fish) was observed under a light microscope, melanophores were horizontally expanded and had a few processes filled with melanosomes. They were isolated from one another. Some melanophores looked black, while others were d&k brown. On observation with a transmission electron microscope, the epidermal melanophore of cat fish was highly branched and small segments of processes were found frequendy m the vidnity of the interecellular spaces. The cross section of the processes of melanophore was almost circular, and often invested by a thin layer of epidermal cells. Some processes, however, occurred free m the wide interecellular spaces or at the cytoplasm of the superilcial layers. In the mature melanophore, the cell organelles including melanosomes, mitochondria and free ribosomes were prominent in the perinuclear portions. Many melanosomes were spherical or elipsoidal in shape. Each melanosomes was surrounded by a limiting membrane. The processes of the mature melanophore were well developed, but the processes of the immature melanophores were incompletely developed.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.25-39
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• 1997

The morphology of the ductuli efferentes of the Korean native pheasants were observed in order to obtain a basic data for further studying reproductive physiology and other male genital organs. The mature (14-16 months after hatching) male pheasants were used in this study. The specimens from pheasants were collected on a monthly basis. The general morphological changes of the ductuli efferentes were observed with hematoxylineosin stain, and semithin section by light microscope. The ultrastructural changes of the ductuli efferentes were investigated with ultrathin section by transmission electron microscope. The results obtained are summarized as follows : 1. During the breeding season, the average height of ductuli efferentes epithelium was $23.45{\pm}2.34{\mu}m$ and was largely decreased by $17.85{\pm}2.01{\mu}m$ during the non-breeding season. The thickeness of interstitial tissue was comparatively increased during the non-breeding season. 2. During the breeding season, the epithelial cells of ductuli efferentes were well developed. During the non-breeding season, epithelial layer and lumen of ductuli efferentes, were markedley reduced compared with those of breeding season. 3. Morphological changes of the ductuli efferentes underwent periodic changes paralleling to the spermatogenic cycle. 4. At least two different cell types were identified in the epithelium of ductuli efferentes, namely non-ciliated and ciliated cells. 5. The ciliated cells possess many vesicles, slightly smaller than those of the non-ciliated cells. 6. The ciliated cells contained numerous mitochondria, smooth and rough endoplasmic reticulum, Golgi complex, lysosome, and oval nuclei. The non-ciliated cells had a irregular nuclei and a cytoplasm containing few organelles. 7. During the breeding season, a number of vesicles, rough and smooth endoplasmic reticulum, Golgi complex, and mitochondria were distinctively showed in the epithelial cells but in the non-breeding season only a few observed.

• Molecules and Cells
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• v.43 no.7
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• pp.645-661
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• 2020

Leaf senescence is a developmental process by which a plant actively remobilizes nutrients from aged and photosynthetically inefficient leaves to young growing ones by disassembling organelles and degrading macromolecules. Senescence is accelerated by age and environmental stresses such as prolonged darkness. Phytochrome B (phyB) inhibits leaf senescence by inhibiting phytochrome-interacting factor 4 (PIF4) and PIF5 in prolonged darkness. However, it remains unknown whether phyB mediates the temperature signal that regulates leaf senescence. We found the light-activated form of phyB (Pfr) remains active at least four days after a transfer to darkness at 20℃ but is inactivated more rapidly at 28℃. This faster inactivation of Pfr further increases PIF4 protein levels at the higher ambient temperature. In addition, PIF4 mRNA levels rise faster after the transfer to darkness at high ambient temperature via a mechanism that depends on ELF3 but not phyB. Increased PIF4 protein then binds to the ORE1 promoter and activates its expression together with ABA and ethylene signaling, accelerating leaf senescence at high ambient temperature. Our results support a role for the phy-PIF signaling module in integrating not only light signaling but also temperature signaling in the regulation of leaf senescence.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.357-364
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• 2017

In this study, we aimed to generate a series of versatile tagging plasmids that can be used in diverse molecular biological studies of the fungal pathogen Cryptococcus neoformans. We constructed 12 plasmids that can be used to tag a protein of interest with a GFP, mCherry, $4{\times}FLAG$, or $6{\times}HA$, along with nourseothricin-, neomycin-, or hygromycin-resistant selection markers. Using this tagging plasmid set, we explored the adenylyl cyclase complex (ACC), consisting of adenylyl cyclase (Cac1) and its associated protein Aca1, in the cAMP-signaling pathway, which is critical for the pathogenicity of C. neoformans. We found that Cac1-mCherry and Aca1-GFP were mainly colocalized as punctate forms in the cell membrane and non-nuclear cellular organelles. We also demonstrated that Cac1 and Aca1 interacted in vivo by co-immunoprecipitation, using $Cac1-6{\times}HA$ and $Aca1-4{\times}FLAG$ tagging strains. Bimolecular fluorescence complementation further confirmed the in vivo interaction of Cac1 and Aca1 in live cells. Finally, protein pull-down experiments using $aca1{\Delta}$::ACA1-GFP and $aca1{\Delta}$::ACA1-GFP $cac1{\Delta}$ strains and comparative mass spectrometry analysis identified Cac1 and a number of other novel ACC-interacting proteins. Thus, this versatile tagging plasmid system will facilitate diverse mechanistic studies in C. neoformans and further our understanding of its biology.

• The Korean Journal of Zoology
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• v.36 no.4
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• pp.562-579
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• 1993

출생후 발생에 따른 흰쥐 전뇌 기저부의 Mevnert 기저핵(nucleus basalis of Mevnert)에서 신경성장인자 수용체(nerve growth factor receptor, NGFr)를 함유하는 신경세포의 면역반응성 및 분포, 세포형의 분류, 각 형별 출현율 및 세포 크기 그리고 세포소기관과 NGFr 면역반응과의 관계를 조사하였다. NGFr 면역반응 신경세포들은 출생후 초기 발생에서 세포질 뿐만 아니라 원형질 막에서도 면역반응을 보였으나, 성체에서는 세포질에서만이 면역반응을 보였다. NGFr 면역반응 신경세포는 형태학적 특징인 세포체의 모양과 장·단축의 비를 기준으로 5가지 형, 즉 1) 원형, 2) 난형, 3) 세장형. 4) 방추형, 5) 삼각형(또는 다각형)세포로 구분되었다 원형과 난형 세포는 출생후 0일에서 각각 15.4%. 50.7%의 높은 출현율을 보였으나, 발생이 진행되면서 점차 감소하여 성체에서 각각 7.8%, 28.6%의 출현율을 보였다 반면, 세장형, 방추형 및 삼각형세포는 출생후 0일에서 각각 22%, 2.6% 9.2%의 낮은 출현율을 보였으나, 발생이 진행되면서 지속적으로 증가하여 성체에서는 각각 29 9%, 5.2%, 28.5%의 높은 출현율을 보였다. 출생후 0일에서 신경세포체의 부피는 매우 작았으나(1,642mm3), 발생에 따라 점차 증가하여 14일, 21일에서는 성체에서보다 매우 컸다(각각 6.745, 6,755mm3) 원형 및 난형세포체의 부피는 21일에서(각각 7 955. 7.020mm3), 세장형 방추형 그리고 삼각형세포체의 부피는 14일에서 제일 컸다(각각 7,067, 6,237, 7,748 mm3) 대체적으로 삼각형세포체의 부피가 제일 컸으며, 방추형세포체의 부피가 제일 작았다. 출생후 순일에서의 전자현미경적 관찰에서 세포소기관중 조면소포체, Golgi체, multivesicular body 그리고 세포표면 원형질막이 강한 NGFr 면역반응을 보였다. 위의 결과들로 미루어 MGFr은 출생후 흰쥐 전뇌 기저부 Meynert 기저핵 신경세포의 분화 및 분포와 밀접한 관계를 갖는 것으로 생각된다.

• Journal of Life Science
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• v.19 no.7
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• pp.859-865
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• 2009

Microtubules, a major cytoskeleton, form parallel arrays in the axon and are oriented with their plus ends toward the cell periphery. Kinesin superfamily proteins (KIFs) are the molecular motors acting in the microtubule-based motilities of organelles in cells. Here, we used the yeast two-hybrid system to identify the protein that interacts with the coiled-coil domain of KIF1A and found a specific interaction with microtubule-destabilizing factor SCG10. SCG10 bound to the amino acid residues between 400 and 820 of KIF1A, but not to other KIFs in the yeast two-hybrid assay. The coiled-coil domain of SCG10 is essential for interaction with KIF1A. In addition, this specific interaction was also observed in the Glutathione S-transferase pull-down assay. An antibody to SCG10 specifically co-immunoprecipitated KIF1A associated with SCG10 from mouse brain extracts. These results suggest that KIF1A motor protein transports SCG10-containing vesicles along microtubules in neurons.

• Applied Microscopy
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• v.36 no.1
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• pp.17-23
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• 2006

The pregnant rats were given a drinking water administration of the sodium fluoride and normal saline for control animals. The sodium fluoride produced cellular changes of odontoblast with consistent response. Compare to control group, the odontoblasts that were administrated by sodium fluoride, showed significantly ultrastructural differences including large number of free ribosomes and swelled mitochondria in dose-dependent manner (300 ppm). From fine structural and morphological investigations of the changes in odontoblast, there were three distinctive structural changes: (1) destruction of the endoplasmic reticulum, (2) swelling of the mitochondria, and (3) severe cellular derangement of the endoplasmic reticulum and mitochondria. From this consecutive structural change, we observed that sodium fluoride temporarily affects the cell organelles in odontoblasts (100, 200 ppm), suggesting it is important that optimal concentration of the sodium fluoride in developing fetus of the rat.

• Journal of Life Science
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• v.17 no.12
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• pp.1760-1765
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• 2007

Proteins are involved in promoting or controlling virtually every event on which our lives depend. Proteins are synthesized in cytosol and in the endoplasmic reticulum where their synthesis machinery are tightly controlled. However, not all of newly synthesized proteins are survived and conduct their essential functions to maintain cell's lives. It was reported that one-third of synthesized proteins are rapidly destroyed by proteasome under the most physiological conditions. full-length translated proteins, which survived, must undergo proper folding and assemble process. Some proteins are spontaneously folded while others require molecular chaperones and folding enzymes to be properly folded. Molecular chaperones are ubiquitously present within the subcellular organelles and from bacteria to animals and plants. Among those members of Hsp70 family have been extensively studied and their regulators have been discovered in the last decade. Here, a brief overview is presented for functional mechanism of Hsp70 homologues and the roles of their regulators. Since biological function of Hsp70 family other than chaperonic function are expending the review would give basic understanding of partnership between Hsp70 family and their regulators.