• Journal of Life Science
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• v.19 no.4
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• pp.549-552
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• 2009

Genetic mutations by gene fusion result from chromosomal rearrangement, trans-splicing, and intergenic splicing. Trans-splicing is a phenomenon in which two pre-mRNAs grow together into one. We analyzed the trans-splicing products in embryonic stem cells. By using bioinformatic tools, 70 trans-splicing transcripts were identified. They are classified into 6 types according to fusion pattern: 5'UTR-5'UTR, 5'UTR-3'UTR, 3'UTR-3'UTR, 5'UTR-CDS, 3'UTR-CDS, CDS-CDS. The fusion products are more abundant in CDS regions than in UTR regions, which contain multiple intron numbers. Chromosome analysis showing gene fusion via trans-splicing indicated that chromosomes 17 and 19 were activated. These data are of great use for further studies in relation to fusion genes and human diseases.

• Korean Journal of Medicinal Crop Science
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• v.16 no.1
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• pp.20-26
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• 2008

Anemarrhena asphodeloides (Korean name "Ji-Mo") has been used for oriental medicinal purposes in Korea, China and Japan. In this study, 29 A. asphodeloides samples were collected including 3 certified A. asphodeloides plants and many commercially marketed A. asphodeloides products. Chloroplast trnL-F regions of the "Ji-Mo" samples were sequenced and used to identify whether the samples were genuine A. asphodeloides or not. As the result, the trnL-F sequences of all the "Ji-Mo" samples were shown to be identical and it was proven that commercially available medicinal products "Ji-Mo" are genuine A. asphodeloides. Phylogenetic tree of. A. asphodeloides using the trnL-F sequences was constructed and compared with phylogenetic tree using rubisco large subunit (rbcL) gene sequences. In these tree, A. asphodeloides was affiliated in the family Agavaceae in the order Asparagales. It is proven that trnL-F phylogenetic tree is useful to study taxonomic position of A. asphodeloides.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.391-399
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• 2016

Melithiazols are antifungal substances produced by the myxobacteria Melitangium lichenicola, Archangium gephyra, and Myxococcus stipitatus. Melithiazol biosynthetic genes have been identified in M. lichenicola, but not in A. gephyra and M. stipitatus until now. We identified a 37.3-kb melithiazol biosynthetic gene cluster from M. stipitatus DSM 14675 using genome sequence analysis and mutational analysis. The cluster is comprised of 9 genes (MYSTI_04973 to MYSTI_04965) that encode 4 polyketide synthase modules, 3 non-ribosomal peptide synthase modules, a putative fumarylacetoacetate hydrolase, a putative S-adenosylmethionine-dependent methyltransferase, and a putative nitrilase. Disruption of the MYSTI_04972 or MYSTI_04973 gene by plasmid insertion resulted in defective melithiazol production. The organization of the melithiazol biosynthetic modules encoded by 8 genes from MYSTI_04972 to MYSTI_04965 was similar to that in M. lichenicola Me l46. However, the loading module encoded by the first gene (MYSTI_04973) was different from that of M. lichenicola Me l46, explaining the difference in the production of melithiazol derivatives between the M. lichenicola Me l46 and M. stipitatus strains.

• Journal of Science and Technology Studies
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• v.1 no.2 s.2
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• pp.423-438
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• 2001

The purpose of this study is to understand how a teacher's teaching can be changed while he or she teaches the same contents in different classes. The qualitative research method was used in this study. Data were collected from classroom observations, several in-depth interviews, and stimulated-recall interviews after each class. All the data were transcribed and analyzed interpretively, and then, the results of the analysis were checked by each participating teacher. The results are as follows: First, changes appeared in each class in terms of the teaching items, tools, sequence, and time, even though the same teacher taught the same contents. It showed that the teacher's teaching practice changed immediately and intuitively in class. Second, teachers tried to implement "exploratory teaching" or "move-testing teaching" to address the emerging problems during their teaching. They then reflected on and modified their own teaching. This type of change, which happened during the teaching practice, can be an example of "Reflection-in-practice." Thus, the results of this study can provide helpful insights into how teachers might adapt and reflect in their teaching. It suggests that teachers need to recognize their subconscious teaching changes and learn "Reflection-in-practice."

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.5
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• pp.413-421
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• 2015

Since the first Cubesat was launched in 2003, there have been more than 230 Cubesats launched so far. Due to their small size and lightweight, Cubesats were launched by utilizing the empty space of regular launch vehicle. However, this launch method has a weakness that has been easily affecting by the schedule of major payloads. As a new solution to this problem, it has been proposed that a robot arm installed on ISS would be used to launch Cubesats. The orbits of Cubesat deployed from the ISS in various angles and directions are analyzed in this paper. We also analyze the possibility of collision between the Cubesat and ISS within the operational orbit of the CubeSat and eventually calculate the optimal angle of a robot arm, which maximizes the lifetime of Cubesat and minimizes the risk of collision between the Cubesat and ISS.

• Journal of Life Science
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• v.20 no.1
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• pp.97-102
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• 2010

Streptomyces platensis YK-2, newly isolated from forest soil, produces transglutaminase (TGase), which catalyses an acyl transfer reaction between the primary grade amine and protein or $\gamma$-carboxyamide group of peptide bound glutamine residues. For a molecular genetic study of S. platensis, an effective transformation method was established by using a conjugal transfer of DNA from Escherichia coli to spores of actinomycetes. The highest transconjugation frequency of S. platensis was obtained on an MS medium containing 50 mM $MgCl_2$, using $5{\times}10^7\;E$. coli as a DNA donor and $1{\times}10^8$ spores without heat treatment as a host. We also identified that S. platensis contains a single attB site within an ORF encoding a pirin-homolog, and that its attB site sequence shows high homology to that of S. logisporoflavus. In addition, it was confirmed by phenotypic analyses of exconjugants that the introduction of heterologous DNA into the attB site of the S. platensis chromosome does not affect its morphological differentiation and TGase production.

• Journal of Mushroom
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• v.10 no.3
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• pp.143-149
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• 2012

Armillaria spp are well known as a symbiotic fungus with Gastrodia elata. This study was carried out to identify and analyze the genetic relationships among 83 strains of Armillaria spp.. The amplified internal transcribed spacer(ITS) region of the rDNA was about 500~750 bp long and identified by 9 strains; A. mellea, A. tabescens, A. ostoyae, A. gallica, A. novae-zenlandia, A. cepistipes, A. nabsnona, A. gemina, A. sinapina. Sequence analysis showed that 52% of strains were different with original identification. A. gallica, A. cepistipes and A. gemina were so close phylogenetic relationship, that was difficult to classify using ITS region. In A. gallica, 12 strains including ASI10104 were showed a close phylogenetic relationship with A. gallica, A. cepistipes and A. gemina. ASI10017 and ASI10114 were classified as the A. sinapina group, ASI10045 was the A. borealis group, ASI10002 and ASI10025 were the A. ostoyae group. So more studies need for more accurate identification and determine the phylogenetic relationships of Armillaria spp.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.242-249
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• 2018

This study was conducted to develop an SNP set that can be useful for marker-assisted breeding (MAB) in watermelon (Citrullus. lanatus L) using Genotyping-by-sequencing (GBS) analysis of 20 commercial elite watermelon inbreds. The result of GBS showed that 77% of approximately 1.1 billion raw reads were mapped on the watermelon genome with an average mapping region of about 4,000 Kb, which indicated genome coverage of 2.3%. After the filtering process, a total of 2,670 SNPs with an average depth of 31.57 and the PIC (Polymorphic Information Content) value of 0.1~0.38 for 20 elite inbreds were obtained. Among those SNPs, 55 SNPs (5 SNPs per chromosome that are equally distributed on each chromosome) were selected. For the understanding genetic relationship of 20 elite inbreds, PCA (Principal Component Analysis) was carried out with 55 SNPs, which resulted in the classification of inbreds into 4 groups based on PC1 (52%) and PC2 (11%), thus causing differentiation between the inbreds. A similar classification pattern for PCA was observed from hierarchical clustering analysis. The SNP set developed in this study has the potential for application to cultivar identification, F1 seed purity test, and marker-assisted backcross (MABC) not only for 20 elite inbreds but also for diverse resources for watermelon breeding.

• Pediatric Infection and Vaccine
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• v.19 no.2
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• pp.71-78
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• 2012

Purpose: Human bocavirus (hBoV), a recently discovered virus, has been detected in children with respiratory tract infections worldwide. The aim of this study was to analyze the frequency and molecular phylogeny of hBoV in the respiratory samples of children with acute respiratory tract infections in 2010. Methods: Nasopharyngeal samples were collected from 953 children with lower respiratory tract infections at Severance children's hospital in Korea from January 2010 to December 2010. We applied the multiplex PCR technique for the identification of 12 respiratory viruses from the samples. Among the total specimens, hBoV positive samples were subjected to phylogenetic analysis by sequencing a fragment of the VP1/VP2 gene junction. Results: hBoV was detected in 141 (14.8%) among 953 patients. The 61.7% of hBoV-positive samples were found to co-exist with other respiratory viruses. The results of phylogenetic analysis showed that all 141 hBoV-positive isolates were identified as hBoV 1, revealing a high similarity among the isolates (>98%). Conclusion: hBoV 1 with minimal sequence variations circulated in children with acute respiratory infections during 2010. More research is needed to determine the clinical severity and outcomes of the minimal sequence variations.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.1-8
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• 2012

This study aimed to investigate the single nucleotide polymorphisms (SNPs) of the porcine MC4R gene and validate the effect of the MC4R genotype for marker assisted selection (MAS). Six amplicons were produced to analyze the entire base sequences of the porcine MC4R gene and six SNPs were detected (c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, c.892A>G-Asp298Asn, and c.*430A>T). Linkage disequilibrium (LD) of the six SNPs was analyzed by performing haploid analysis. There was a perfect linkage disequilibrium in c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, and c.*430A>T. Only the c.892A>G (Asp298Asn) SNP showed a very low LD with an $r^2$ value of 0.028 and the D' value of 0.348. As a result, the two SNPs-c.707A>G (Arg236His) and c.892A>G (Asp298Asn)-were selected to extract the genotype frequencies from the 5 pig breeds by using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotype analysis method. The SNP frequency of c.707A>G (Arg236His) indicated the presence of the A (His) allele only in Yorkshire, while the G allele was fixed in the KNP, Landrace, Berkshire, and Duroc. Association analysis was carried out in 484 pigs with the c.707A>G (Arg236His) SNP and the meat quality traits of four different pig cross populations: a significant association was noted in crude fat, sirloin moisture, meat color, and the degree of red and yellow coloration. The frequency of the c.892A>G(Asp298Asn) SNP genotype varied among the breeds; while Duroc showed the highest frequency of the A (Asn) allele, KNP showed the highest frequency of the G (Asp) allele. Association analysis was carried out in 1126 pigs with the c.892A>G (Asp298Asn) SNP and the meat quality traits of four pig populations: a highly significant linkage was noted in the back-fat thickness (P<0.002). It was found that the back-fat thickness was higher in individuals with the AA genotype than in those with the AG or GG genotype. Thus, in this study, we verified that the c.892A>G (Asp298Asn) SNP in the pig MC4R gene has a sufficient effect as a gene marker for MAS in Korean pork industry.