• Molecules and Cells
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• v.22 no.3
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• pp.247-253
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• 2006

Protein modification by small ubiquitin-like modifier (SUMO) controls diverse cellular functions of protein targets including transcription factors and coregulators mainly in the nucleus and participates in maintaining cellular homeostasis. In addition, SUMO system plays important roles in DNA damage repair and maintaining genome integrity. Thus, in some cases, the loss of control on SUMOylation or deSUMOylation processes causes a defect in maintaining homeostasis and hence gives a cue to cancer development. Furthermore, recent study showed that SUMO system is also involved in cancer metastasis. In this review, we will summarize and discuss the possible role of SUMO system in cancer development and metastasis.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.215-222
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• 2015

This paper sketches the strategies and designs for monitoring system of swine genetic improvement. The system should reflect every side of pig production. The system leads us to assess the efficiency of pig production and the scope of the system includes not only nucleus, multiplying and commercial herds, but also packing and processing sectors. For more accurate statistics, data for this monitoring system must be collected from all above mentioned areas, but not by random sampling. Futhermore, data analysis results including seedstocks and distribution information of genetic trend should be included in the system. The schema of knowledge database system could be employed in the system. The monitoring system in the final destination would unify the systems derived from various sources and provide any solution in swine industry including pig breeding.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.70-76
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• 2005

It is known that natural awakening of us in the morning is due to stimulation of the reticular activation system through biological clock in the suprachiasmatic nucleus of hypothalamus by the morning sunlight. If we sleep at dark rooms without windows and so without morning sunlight, thus, it is not easy fur us to get up refreshingly in the morning. In this paper, we propose an automatic sunrise household lighting system that helps us fer getting up cheerfully in the morning even if we sleep in dark rooms without morning sunlight. The proposed lighting system is an embedded system that turns automatically on the electric lamp and makes it brighter and brighter coincidently with the actual sunrise. The proposed system is composed of a PIC microcontroller with flash memory, a real-time clock IC, a D/A converter, an amplifier, a dimmer unit, a light bulb, a display panel and a keyboard. The validity of the proposed intelligent lighting system is demonstrated via a prototype production and experimentation.

• Animal cells and systems
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• v.2 no.1
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• pp.71-80
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• 1998

Glutamate dehydrogenase (GDH) is one of the main enzymes involved in the formation and metabolism of the neurotransmitter glutamate. In the present study, we investigated the distribution of the GDH-immunoreactive cells in the rat brain using monoclonal antibodies against bovine brain GDH isoprotein. GDH-immunoreactive cell were distributed in the basal ganglia, thalamus and the nuclei belong to substantia innominata, and its connecting area, subthalamic nucleus, zona incerta, and substantia niqra. We could see GDH-immunoreactive cells in the hippocampus, septal nuclei associated with the limbic system, the anterior thalamic nuclei connecting between the hypothalamus and limbic system, and its associated structures, amygdaloid nuclear complex, the dorsal raphe and median raphe nuclei and the reticular formation of the midbrain. The GDH-immunoreactive cells were shown in the pyramidal neurons of the cerebral cortex, the Purkinie cells of the cerebella cortex, their associated structures, ventral thalamic nuclei and the reticular thalamic nuclei that seem to function as neural conduction in the thalamus.

• Anatomy and Cell Biology
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• v.56 no.2
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• pp.271-275
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• 2023

The abducens nerve (AN; cranial nerve VI) exits the brainstem at the inferior pontine sulcus, pierces the dura of the posterior cranial fossa, passes through the cavernous sinus in close contact to the internal carotid artery (ICA) and traverses the superior orbital fissure to reach the orbit to innervate the lateral rectus muscle. At its exit from the brainstem, the AN includes only axons from lower motor neurons in the abducens nucleus. However, as the AN crosses the ICA it receives a number of branches from the internal carotid sympathetic plexus. The arrangement, neurochemical profile and function of these sympathetic axons running along the AN remain unresolved. Herein, we use gross dissection and microscopic study of hematoxylin and eosin-stained sections and sections with tyrosine hydroxylase immunolabeling. Our results suggest the AN receives multiple bundles of unmyelinated axons that use norepinephrine as a neurotransmitter consistent with postganglionic sympathetic axons.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.423-428
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• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.87-106
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• 2005

In order to evaluate the mechanism of transmission as well as processing of sensory information originating from low-threshold mechanoreceptor in oral and maxillofacial region at primary synaptic region of trigeminal nervous system, vibrissa afferent fibers of adult cat were labeled with intra-axonal HRP injection. Serial sections containing labeled boutons were obtained from the piece of trigeminal interpolar nucleus. Under electron microscope, total 30 labeled boutons were observed, and ultrastructural characteristics, frequency of occurence, synaptic organizations of vibrissa afferent terminals were analysed. The results were as follows: 1. Labeled boutons contained clear, spherical synaptic vesicles with diameter of 45$\sim$55nm. They formed asymmetrical synapse with dendrites showing definite postsynaptic density, larger synaptic cleft, multiple synaptic structures at various regions. With unlabeled axon terminals(p-ending) containing polymorphic synaptic vesicles, they formed symmetrical synapse showing indefinite postsynaptic density and narrower synaptic area. 2. Each labeled bouton formed 1 to 15 synapses, the average of 4.77$\pm$3.37 contacts per labeled bouton, with adjacent neuronal profiles. Relatively complex synaptic organization, which formed synapses with more than 5 neuronal profiles, was observed in a large number(46.7%, n=14) of labeled boutons. 3. Axo-somatic synapse was not observed. The number of axo-dendritic synapse was 1.83$\pm$1.37 per labeled bouton. Majority(85.0%) of axo-dendritic synapses were formed with dendritic shafts, nonprimary dendrites(n=47, 1.57$\pm$1.38/1 bouton), however, synapses formed with primary dendrites(n=6, 0.20$\pm$0.41/1 bouton) or dendritic spines(n=2, 0.07$\pm$0.25/1 bouton) were rare. 4. 76.7%(n=23) of labeled boutons formed axo-axonic synapse (2.93$\pm$2.36/1 bouton) with p-endings containing pleomorphic vesicles. Synaptic triad, in which p-endings formed synapses with labeled boutons and dendrites adjacent to the labeled boutons simultaneoulsy, were also observed in 60.0%(n=18) of labeled boutons. From the above results, vibrissa afferent terminals of adult cat showed distinctive synaptic organization in the trigeminal interpolar nucleus, thus, suggests their correlation with the function of the trigeminal interpolaris nucleus, which participates in processing of complex sensory information such as two-point discrimination and motivational-affective action. Further studies on physiologic functions such as quantitative analysis on ultrastructures of afferent terminals and nerve transmitters participating in presynaptic inhibition are required.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.6
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• pp.1360-1365
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• 2013

Juvenile sea cucumber, Apostichopus japonicus(wet weight $1.0{\pm}0.2g$, n=250) acclimated to environmental conditions($17^{\circ}C$, 33 psu) during 4 weeks for observation of survival and structural variation of integumentary system according to various salinity concentration. After that, it was exposed 0, 5, 10, 15, 20, 25, 30, 35, 40 psu in 96h, and recovered during 7 days. In this results, The 96-h lethal concentration(LC50) for sea cucumber was a salinity of 21.05 psu. Integumentary system of the sea cucumber exposed to below the salinity of 20 psu mainly observed thickness reduction of epidermal layer, nucleus condensation of epithelial cells, decreased of mucous cells and loose arrangement of connective tissue in dermal layer. Integumentary system of the sea cucumber exposed a salinity of 40 psu mainly observed nucleus hypertrophy of epithelial cells, increase of mucous cells and tight arrangement of connective tissue in dermal layer. Also, observed secretory cells showing the alcian blue(pH 2.5) positive. During 96-h exposure, this cells decreased after increase below the salinity of 20 psu but increased in the salinity of 40 psu compared with 25-35 psu.

• Development and Reproduction
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• v.11 no.2
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• pp.97-104
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• 2007

This study describes the spermatogenesis and sperm ultrastructure of the spiny top shell, Batillus cornutus using light and electron microscopy. The spiny top shells were collected by divers in the coastal water of Wandogun, Cheollanamdo, Korea(N $34^{\circ}13'$, E $126^{\circ}47'$) at May 2003. Spiny top shells of $60.0{\sim}69.9\;mm$ in shell height were used in this study. The testis comprises many spermatogenic follicles which contains germ cells in different developmental stages. The primary spermatocytes in the pachytene stage were characterized by synaptonemal complexes. The early spermatids were characterized by appearance of Golgi complex, increased karyoplasmic electron density and tubular mitochondria. In early spermatid the mass of proacrosomal granules consists of numerous heterogeneous granules with high electron density. From the mid-stage of spermiogenesis the well-developed mitochondria aggregate posterior to the nucleus, and surround the proximal and distal centrioles. In this stage, proacrosomal granules are condensed and form a acrosome with thin envelope. During the late spermiogenesis, the acrosome begins to elongate and then became conical. The sperm consists of head, mid-piece and tail. The head comprises a round nucleus and a conical acrosome. Acrosomal rod of microfibrous is observed between nucleus and acrosome. Five mitochondria observed in mid-piece. And tail has the typical "9+2" microtubular system originates from the centrioles.

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.133-141
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• 1994

The discharge patterns and peripheral nerve inputs to cardiovascular neurons were investigated in rostral ventrolateral medulla (RVLM) and raphe nucleus of cats. The data from the two were compared to determine their roles in cardiovascular regulation and the endogenous analgesic system. Animals were anesthetized with ${\alpha}-chloralose$ and single cell activities were recorded by carbon-filament microelectrode and their relationships with cardiovascular activity were analyzed. In RVLM area, a total of thirty-three cells were identified as cardiovascular neurons. During one cardiac cycle, the mean discharge rate of the neurons was $1.96{\pm}0.29$ and the peak activity was observed 45 ms after the systolic peak of arterial blood pressure. Thirteen cells could be activated antidromically by stimulation of the the $T_2$ intermediolateral nucleus. Forty-three raphe neurons were identified as cardiovascular neurons whose mean discharge rate during one cardiac cycle was $1.02{\pm}0.12$. None of these cells could be activated antidromically. Study of the interval time histogram of RVLM neurons revealed that the time to the first peak was $128{\pm}20.0\;ms$, being shorter than the period of a cardiac cycle. The same parameter found from the raphe neurons was $481{\pm}67.2\;ms$, which was much longer than the cardiac cycle length. Of seventeen RVLM neurons examined ten received only the peripheral $A{\delta}-afferent$ inputs, whereas six RVLM neurons received both $A{\delta}-$ and C-inputs; the remaining one cell received an inhibitory peripheral C-input. In contrast, nine of eleven raphe neurons were found to receive $A{\delta}-inputs$ only. We conclude that the main output of cardiovascular regulatory influences are mediated through the RVLM neurons. The cardiovascular neurons in the raphe nucleus appear to serve as interneurons transferring cardiovascular afferent information to the raphespinal neurons mediating the endogenous analgesic mechanisms.