• Journal of Life Science
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• v.24 no.10
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• pp.1046-1054
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• 2014

Beta-1,3-glucanase is widely used in various biotechnological and industrial processes, with over-production required to enable versatile utilization. We examined the overexpression of ${\beta}$-1,3-glucanase (EXGA) from Aspergillus oryzae using ${\delta}$-sequence-mediated integration. We constructed $pRS{\delta}$-exgA and $pRS{\delta}K$-exgA plasmids for integration of the EXGA gene into various chromosomes of Saccharomyces cerevisiae. These plasmids contain the ADH1 promoter for constitutive expression, a signal sequence (exoinulinase signal sequence [INU1 s.s]) for secretory production, and a ${\delta}$-sequence for integration of ${\beta}$-1,3-glucanase. The $pRS{\delta}$-exgA plasmid was transformed into the S. cerevisiae $BY4742{\Delta}exg1$ strain, and ${\beta}$-1.3-glucanase was stably overexpressed and secreted. Another plasmid, $pRS{\delta}K$-exgA, was introduced into the S. cerevisiae $BY4742{\Delta}exg1$ (YKY082) strain, and overexpression of ${\beta}$-1,3-glucanase was examined by inducible integration under geneticin selection. The activity of ${\beta}$-1,3-glucanase increased in accordance with a rise in the geneticin concentration, with 0.8 mg/ml of geneticin suitable for overexpression of ${\beta}$-1,3-glucanase. Subsequently, $pRS{\delta}K$-exgA was repeatedly transformed for sequential ${\delta}$-integration. The activity of ${\beta}$-1,3-glucanase reached about 0.063 unit/ml/$OD_{600}$, 0.095 unit/ml/$OD_{600}$, 0.131 unit/ml/$OD_{600}$ and 0.165 unit/ml/$OD_{600}$ by the first, second, third, and fourth round of integration, respectively. According to the increase in the activity of ${\beta}$-1,3-glucanase by sequential ${\delta}$-integration, the copy number (integration rate) of the EXGA gene also increased in various chromosomes. These results suggest that recombinant ${\beta}$-1,3-glucanase activity can be sequentially increased by repeated ${\delta}$-sequence integration.

• Land and Housing Review
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• v.5 no.1
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• pp.53-56
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• 2014

Hong Kong, a well-known metropolis characterized by skyscrapers on both sides of the Victoria Harbour, consists mainly of 3 parts, namely the Hong Kong Island, the Kowloon peninsula and the New Territories (N.T.) which is the land area north of Kowloon plus a number of outlying islands. Located in the N.T. are all the new towns, market towns; and in the plains and valleys lie scattered village houses of not more than 3 storeys within the confines of well-defined village. These village houses are governed by a rural housing policy that could be traced back to the very beginning of the former British administration in the N.T. By the Convention of Peking of 1898, the N.T., comprising the massive land area north of Kowloon up to Shenzhen River and 235 islands, was leased to Britain by China for 99 years from 1st July 1898. Soon after occupation, the colonial government conducted a survey of this uncharted territory from 1899 to 1903, and set up a land court to facilitate all land registration work and to resolve disputed claims. By 1905, the Block Crown Leases with Schedule of Lessees and details of the lots, each with a copy of the lot index plan (Demarcation Plan) were executed. Based on the above, Crown rent rolls were prepared for record and rent collection purposes. All grants of land thereafter are known as New Grant lots. After completion and execution of the Block Crown Lease in 1905, N.T. villagers had to purchase village house lots by means of Restricted Village Auctions; and Building Licences were issued to convert private agricultural land for building purposes but gradually replaced by Land Exchanges (i.e. to surrender agricultural land for the re-grant of building land) from the early 1960's until introduction of the current Small House Policy in October 1972. It was not until the current New Territories Small House Policy came into effect in December 1972 that the Land Authority can make direct grant of government land or approve the conversion of self-owned agricultural land to allow indigenous villagers to build houses within the village environs under concessionary terms. Such houses are currently restricted to 700 square feet in area and three storeys with a maximum height of 27 feet. An indigenous villager is a male descendent of a villager who was the resident of a recognized village already existing in 1898. Each villager is only allowed one concessionary grant in his lifetime. Upon return of Hong Kong to the People's Republic of China on July 1st, 1997, the traditional rights of indigenous villagers are protected under Article 40 of the Basic Law (a mini-constitution of the Hong Kong Special Administrative Region). Also all N.T. leases have been extended for 50 years up to 2047. Owing to the escalating demand and spiral landed property prices in recent years, abuse of the N.T. Small House Policy has been reported in some areas and is a concern in some quarters. The Hong Kong Institute of Land Administration attempts to study the history that leads to the current rural housing policy in the New Territories with particular emphasis on the small house policy, hoping that some light can be shed on the "way forward" for such a controversial policy.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.325-330
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• 2007

RNase E is an essential Escherichia coli endoribonuclease that plays a major role in the decay and processing of a large fraction of RNAs in the cell and expression of N-terminal domain consisted of 1-498 amino acids (N-Rne) is sufficient to support normal cellular growth. By utilizing these properties of RNase E, we developed a genetic system to screen for amino acid substitutions in the catalytic domain of the protein (N-Rne) that lead to various phenotypes. Using this system, we identified three kinds of mutants. A mutant N-Rne containing amino acid substitution in the S1 domain (I6T) of the protein was not able to support survival of E. coli cells, and another mutant N-Rne with amino acid substitution at the position 488 (R488C) in the small domain enabled N-Rne to have an elevated ribonucleolytic activity, while amino acid substitution in the DNase I domain (N305D) only enabled N-Rne to support survival of E. roli cells when the mutant N-Rne was over-expressed. Analysis of copy number of ColEl-type plasmid revealed that effects of amino acid substitution on the ability of N-Rne to support cellular growth stemmed from their differential effects on the ribonucleolytic activity of N-Rne in the cell. These results imply that the genetic system developed in this study can be used to isolate mutant RNase E with various phenotypes, which would help to unveil a functional role of each subdomain of the protein in the regulation of RNA stability in E. coli.

• Journal of fish pathology
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• v.24 no.2
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• pp.65-73
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• 2011

In analysis of DNA viruses from the contaminated shellfish using PCR, preparation method of template DNA is an important factor to get enough copy number of viruses. In this study, we evaluated the efficiency of PCR template of Megalocytivirus (sT50mg-D) DNA obtained from 50 mg digestive gland homogenate of oyster using commercial method, and compared with that obtained from 5 g of the same tissues (T5g-D) after PEG precipitation procedures of virus. Both templates DNA suspended in the same volume of distilled water showed positive results by primary PCR with 35 cycles, and the presence of Megalocytivirus was confirmed in oysters collected from cultured farms in Korea. Moreover, PCR with sT50mg-D allowed us to discriminate the contaminated oyster individually, that can not be done in PCR with T5g-D prepared from the mixture of three different individual oyster to get 5 g digestive gland homogenate. In quantitative analysis with real time PCR, Megalocytivirus concentrations in 50 ${\mu}l$ templates prepared using 0.5~50 mg of one positive sample were appeared in the range 6.14E+00~1.2E+02/${\mu}l$. We were not able to get positive result using template DNA contained less than 6.14E+00 copies. Consequently, 2-step PCR performed with DNA extracts from oyster homogenate of small amount (sT50mg-D) i) was enough to detect the contaminated Megalocytivirus in shellfish, ii) allowed us to do the analysis for individual shellfish rather than mixture of several shellfish and iii) showed the presence of Megalocytivirus in oyster from Korea.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.25-31
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• 2001

The purpose of this study was to investigate the distribution and fluorescence intensity of vasoactive intestinal polypeptide immunoreactive (VIP-IR) cells in rat trigeminal ganglion following pulp extirpation of rat mandibular molar. The animals were divided into control group(n=6) and experimental group(n=6). The experimental animals were sacrificed at 14 days after pulp extirpation. The trigeminal ganglion was removed and immersed in the 4% paraformaldehyde in 0.1M phosphate buffer. Serial frozen sections about $20{\mu}m$ in thickness were cut with a cryostat. The immunofluorescence staining was performed. The rabbit anti-VIP(1 : 8,000) was used as primary antibody and fluorescene isothiocynate(FITC) conjugated anti-rabbit IgG(1 : 80) as secondary antibody. The slides were observed under confocal laser scanning microscope (CLSM). Unprocessed optical sections were obtained and stored on a optical disk. Color pictures were printed by a video copy processor. The results were as follows; 1. The positive ratio of VIP-IR cells in mandibular part of trigeminal ganglion were 7.40% in control group and 28.42% in experimental group(14 days after pulp extirpation). 2. The relative fluorescence intensity of VIP-IR cells in mandibular part of trigeminal ganglion were 87.78 in control group and 138.65 in experimental group. The relative fluorescence intensity of experimental group was 58% higher than that of control group. 3. In optical serial section analysis of VIP-IR cells of experimental group, most of the 9 sections showed high fluorescence intensity. At high magnification, axons of the experimental group displayed greater VIP-IR than in the control group, and the positive cells were mainly of medium size. The result indicate that number and fluorescence intensity of VIP-IR cells were increased in the mandibular part of trigeminal ganglion following pulp extirpation of mandibular molar, and it suggests that VIP could play a role in processing of nociception.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.162-170
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• 2012

The objectives of this study were to isolate and the sequence of novel $F3'H$ gene related to an anthocyanin pathway, and to confirm the expression patterns of the gene involved in the flower color variations of chrysanthemum mutants. In this study, we isolated the full-length cDNAs and the genomic DNAs of an $F3'H$ gene from a wild type (WT) chrysanthemum (cv. Argus) and its three color mutants. The sequence analysis revealed a putative open reading frame of 1,527 bp that encodes a polypeptide of 509 amino acids. Sequence homology ranged from 97% to 99% between 'Argus' and its three color mutants. The sequence analysis from the genomic DNA revealed that the chrysanthemum $DgF3'H$ gene consisted of three exons and two introns spanning a 3,830 bp length. The sizes of the gene for three mutants ranged from a shorter size of 3,828 bp to a longer size of 3,838 bp when compared to the size of WT. The total size of the two introns was 2,157 bp for WT, but those for three color mutants ranged from 2,154 bp to 2,159 bp. A result of an RT-PCR analysis indicated that the color variations of the mutants AM1 and AM2 can be partly explained by the structural modification derived from the sequencial changes in the gene caused by gamma ray. A Southern blot analysis revealed that the $DgF3'H$ gene existing as multiple copies in the chrysanthemum genome. A systemic study will be further needed to provide a genetic mechanism responsible for the color mutation and to uncover any involvement of genetic elements for the expression of the $DgF3'H$ gene for the color variation in chrysanthemum.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.108-116
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• 2009

In this paper, we propose a Ethernet based audio distribution system with a new L1/L2 hybrid switching scheme, and evaluate its performance. The proposed scheme not only offers guaranteed low latency and jitter characteristics that are essentially required for the distribution of high-quality uncompressed audio traffic, and but also provide an efficient transmission of data traffic on the Ethernet environment. The audio distribution system with a proposed scheme consists of a master node and a number of relay nodes, and all nodes are mutually connected as a daisy-chain topology through up and downlinks. The master node generates an audio frame for each cycle of 125us, and the audio frame has 24 time slotted audio channels for carrying stereo 24 channels of 16-bit PCM sampled audio. On receiving the audio frame from its upstream node via the downlink, each intermediate node inserts its audio traffic to the reserved time slot for itself, then relays again to next node through its physical layer(L1) transmission - repeating. After reaching the end node, the audio frame is loopbacked through the uplink. On repeating through the uplink, each node makes a copy of audio slot that node has to receive, then play the audio. When the audio transmission is completed, each node works as a normal L2 switch, thus data frames are switched during the remaining period. For supporting this L1/L2 hybrid switching capability, we insert a glue logic for parsing and multiplexing audio and data frames at MII(Media Independent Interlace) between the physical and data link layers. The proposed scheme can provide a good delay performance and transmission efficiency than legacy Ethernet based audio distribution systems. For verifying the feasibility of the proposed L1/L2 hybrid switching scheme, we use OMNeT++ as a simulation tool with various parameters. From the simulation results, one can find that the proposed scheme can provides outstanding characteristics in terms of both jitter characteristic for audio traffic and transmission efficiency of data traffics.

• Journal of Life Science
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• v.25 no.3
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• pp.349-356
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• 2015

Thanks to recent advances in next-generation sequencing (NGS) technology, diverse livestock species have been dissected at the genome-wide sequence level. As for cattle, there are currently four Korean indigenous breeds registered with the Domestic Animal Diversity Information System of the Food and Agricultural Organization of the United Nations: Hanwoo, Chikso, Heugu, and Jeju Heugu. These native genetic resources were recently whole-genome resequenced using various NGS technologies, providing enormous single nucleotide polymorphism information across the genomes. The NGS application further provided biological such that Korean native cattle are genetically distant from some cattle breeds of European origins. In addition, the NGS technology was successfully applied to detect structural variations, particularly copy number variations that were usually difficult to identify at the genome-wide level with reasonable accuracy. Despite the success, those recent studies also showed an inherent limitation in sequencing only a representative individual of each breed. To elucidate the biological implications of the sequenced data, further confirmatory studies should be followed by sequencing or validating the population of each breed. Because NGS sequencing prices have consistently dropped, various population genomic theories can now be applied to the sequencing data obtained from the population of each breed of interest. There are still few such population studies available for the Korean native cattle breeds, but this situation will soon be improved with the recent initiative for NGS sequencing of diverse native livestock resources, including the Korean native cattle breeds.

• Tuberculosis and Respiratory Diseases
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• v.51 no.6
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• pp.517-529
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• 2001

Background : Surfactant protein C(SP-C) is a hydrophobic 5,000 dalton molecule. SP-C has the primary roles in accelerating surface spreading of a surfactant phospholipid. The filter hybridization and solution hybridization assays are both rapid and sensitive and can be used to measure the RNAs complementary to any cloned DNA sequence. Methods : The authors measured the SP-C mRNA levels quantitatively using solution hybridization and filter hybridization assays to obtain a standard curve equation to quantify the mRNA of unknown samples comparatively. Results : 1. The minimum level of the specimens by solution hybridization was 3 pg for SP-C mRNA. 2. The standard curve equation of the solution hybridization assay between the counts per minute(Y) and the SP-C mRNA transcript input(X) was Y=6.46 X+244. The correlation coefficient was 0.99. 3. The minimum detection level of specimens by filter hybridization was 0.1 ng for SP-C mRNA. 4. The standard curve equation of the filter hybridization assay between the counts per minute(Y) and SP-C mRNA transcript input(X) is Y=2541.6 X+252.7. The correlation coefficient was 0.99. Conclusions : A comparison of CPM/filter in the linear range allowed an accurate and reproducible estimation of the SP-C mRNA copy number. Filter hybridization and solution hybridization assays are both rapid and sensitive and can be used to measure the RNAs complementary to any cloned DNA sequence. It is ideally suited to situations where accurate quantitation of multiple samples is required.

• Korean Journal of Heritage: History & Science
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• v.43 no.4
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• pp.56-77
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• 2010

The tortoise pedestal for the memorial monument of Choe Jin-rip(an army officer in the mid-Joseon Period) in Ijo-ri, Naenam-myeon, Gyeongju is known to have been made in 1740. As such, it was originally understood to be a Joseon imitation of a tortoise pedestal made in the Unified Silla Period. The style of the Ijori Tortoise Pedestal differs from other tortoise pedestals dating back to the same period, and bears no resemblance to the Unified Silla pedestals of which it is a copy. Mullu ilgi, a record of the production of the pedestal, explains that the monument was made before the pedestal. Traces show that the two sides of the bottom of the monument were cut off so that it would fit into the smaller space made on the pedestal. It is scarcely conceivable that they made the pedestal and the platform without considering the bottom size of the monument. The record only states that the monument was made at a temple site named Baegundae, without explaining the details of the production process. This leaves some doubt as to whether its production was undertaken systematically. The cloud patterns engraved on this pedestal look similar to the temporal seriation found on the Tortoise Pedestal of the Royal Tomb of King Muyeol and the Seoangni Tortoise Pedestal of Gyeongju. The lotus pattern decorating the square pedestal on the back of the tortoise is one of a number of patterns that were widely used on roof-tiles in the 8th century, the heyday of the Unified Silla Kingdom. The Ijori Tortoise Pedestal, which represents a tortoise moving forward, displays a liveliness the like of which is rarely found in its cousins remaining in Gyeongju. The layout of the patterns in a queue on the tortoise-shell looks much better schematized than those made at an earlier date. It also looks like a more developed form, with the use of space taken into account. Such factors as the style of the patterns, the incongruity between the monument and its pedestal, and what is stated in the historical record indicate that the Ijori Tortoise Pedestal of Gyeongju was made in the mid-8th century(i.e. during the Unified Silla Period), rather than in the Joseon Period(i.e. the 18th century), as an imitation of earlier ones, including changes in the style unique to the Silla Period.