• Korean Journal of Microbiology
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• v.41 no.2
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• pp.125-128
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• 2005

A 16S ribosomal RNA gene from S. chungbukensis DJ77 has been sequenced. This sequence had a length of 1,502 bp and was extended for 29 bp at 5' and for 37 bp at 3' from the partial sequence (1,435 bp) registered in 2000 year. Besides, 1 bp was newly added near to the 3' end. We made the secondary structure of the 16S rRNA based on E. coli model and found four specific regions. We found constant and variable regions in genus Sphingomonas as the result of multiple alignment of 16S rRNA gene sequences from Sphingomonas spp. and S. chungbukensis DJ77. We found a stem loop structure in S. chungbukensis DJ77, which was only discovered in C. jejuni to date. It showed the structural agreement despite the difference of the sequences from the both organisms. Finally, S. chungbukensis DJ77 belonged to cluster II (Sphingobium) group, after the classification using phylogenetic analysis and nucleotide signature analysis.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.225-229
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• 2015

Echinochloa colona is one of the most problematic weeds in the paddy fields of the world. In recent years, this species is likely to be introduced in Korea due to global warming, the expansion of international trade including agricultural products, and increasing tourists. We tried to identify the species from Korean Echinochloa crus-galli and E. oryzicola in order to establish the control measures in case of the initial influx. For this study, Echinochloa colona collected from the National Plant Germplasm System, USA were examined and E. crus-galli and E. oryzicola were collected in Korea. It is, however, very difficult to identify for Echinochloa species using morphological characters because of numerous interspecific and intraspecific types found in nature. Thus, we barcoded the species using rbcL, matK, and ITS. All three markers identified E. colona very well from the others. ITS alone may be enough as a DNA barcode for E. colona identification, when considering cost and effectiveness. The barcode sequences were deposited to the National Center for Biotechnology Information database for public use.

• Journal of Life Science
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• v.16 no.6
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• pp.994-1000
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• 2006

Stevia rebaudiana Bertoni is a sweet herb of the Asteraceae family originally derived from South America. Twenty three bacterial strains and ten yeast strains were isolated from fermented Stevia extract and identified by general taxonomic methods and molecular genetic method. Isolated strains from fermented Stevia extract include ten species of bacteria which belong to five genus and one species of yeast. Based on 16S and 18S rDNA sequence analysis, phylogenetic trees were constructed. Antimicrobial activity of the isolated strains was examined against various bacteria and plant-pathogenic fungi. Among them, Lactobacillus paracasei SB13 showed strong antibacterial activity towards a wide range of bacteria. These results may be useful to develop environmentally friendly microbial agent for soil improvement.

• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.219-233
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• 1999

Purpose : Respiratory syncytial virus(RSV) is the major cause of lower respiratory tract infection in infants and young children. This study was performed to analyze antigenic and genetic variation of G protein of subgroup A RSV. Methods : One hundred seventy-nine strains isolated at the Seoul National University Children's Hospital over 8 years-period from 1990 through 1998 were analysed for antigenic and genetic variability. Analysis was made by reactivity with monoclonal antibodies raised against RSV, and by restriction mapping and, for selected strains, nucleotide sequencing following amplification of full sequence of G gene by reverse transcription-polymerase chain reaction. Results : Restriction fragment analysis of the amplified G protein gene revealed 23 restriction patterns, 12 of which included more than 2 isolate, and the most frequent genetic type comprised 30% of the strains. Indirect immunofluorescent staining with monoclonal antibodies revealed 6 antigenic types with one predominant pattern accounting for 91% of the total strains. The most frequent antigenic type had 21 restriction patterns, and some viruses with same restiction pattern had different monoclonal antibody reaction pattern. Nucleotide sequence homology of subgroup A was 91~93% between reference(A2, Long) and Korean isolates, 93~99% among Korean isolates. Maximum-parsimony analysis demonstrated that Korean isolates were distinct from reference strains and subgroup A strains were clustered in 4 groups. Conclusion : The restriction analysis pattern of G protein gene identified greater diversity within subgroup A than was seen with the monoclonal analysis and a variety of antigenic and genetic types of RSV are circulating in Korea which are different from reference strains or strains isolated from other countries.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.247-260
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• 2014

To identify the species of Trichogramma occurring in the corn fields of Korea as egg parasitoids of Ostrinia furnacalis, we sequenced the full-length of ITS2 nuclear rDNA from 112 parasitoids collected during this study. As a reference to distinguish species, we also retrieved full-length ITS2 sequences of 60 Trichogramma species from the NCBI GenBank database. On the basis of the size and 3'terminal sequence pattern of the ITS2 sequences, the Trichogramma samples collected in this study were divided into three groups (K-1, -2, and -3). Evolutionary distances (d) within and between groups based on ITS2 sequences were estimated to be ${\leq}0.005$ and ${\geq}0.080$, respectively. In the net average distance between groups or species, the d value between K-1 and T. ostriniae, K-2 and T. dendrolimi, and K-3 and T. confusum was the lowest, with values of 0.016, 0.001, and 0.002, respectively. In the phylogenetic tree, K-1 and K-2 were clustered with T. ostriniae and T. dendrolimi, respectively. However, K-3 was clustered with three different species, namely, T. confusum, T. chilonis, and T. bilingensis. NCBI BLAST results revealed that parasitoids belonging to K-1 and K-2 showed 99% identity with T. ostriniae and T. dendrolimi, respectively. Parasitoids in K-3 collected from Hongcheon showed 99-100% identity with T. confusum and T. chilonis, and one parasitoid in K-3 collected from Gochang had 98% identity with T. bilingensis, T. confusum, and T. chilonis. On the basis of these results, we infer that the species of Trichogramma collected in this study are closely related to T. ostriniae (K-1) and T. dendrolimi (K-2). However, it was not possible to distinguish species of K-3 using the ITS2 sequence alone.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.291-298
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• 2009

A molecular phylogenetic relationship inferred from mitochondrial cytochrome b gene sequence was developed based on analysis of Zacco species distributed in Korea as well as China, Japan and Taiwan. A maximum parsimony (MP) tree showed that Korean Z. temminckii and Z. koreanus formed a monophyletic clade, but the populations of Z. temminckii and Z. koreanus in the 'South Korean Subdistrict' region had genetic similarity with Japanese Z. temminckii. Korean Z. platypus had a closer relationship with Japanese members of the clade than with Chinese Z. platypus, which was more closely related to Opsariichthys uncirostris amurensis. The analysis of neighbor joining (NJ) tree may support a hypothesis that the clade of Z. platypus had genetically diverged from the common ancestor of Zacco species comprising Z. koreanus, Z. temminckii, Z. sieboldii and other species; thereafter a cladogenesis of Z. koreanus and Z. temmminckii had occurred from the ancestor of Z. sieboldii. Moreover, the Chinese Z. platypus had diverged far from the Korean Z. platypus and formed a phylogenetic relationship with O. uncirostris amurensis. Therefore, a more detailed study of the taxonomy and systematics of Zacco species in regard to their zoogeographical distributions is needed.

• The Korean Journal of Mycology
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• v.33 no.1
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• pp.1-10
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• 2005

Nineteen strains of Trametes species were collected from the area of Kangwon Province, Korea. They have a variety of color hands and line-up markings on fruit bodies. Most strains were categorized into four types based on color bands, that is, dark brown, light brown, dark gray and light gray. They also have line-up marking shapes from sparse to compact on fruit bodies. In this study, we tried to investigate the relationship between the genetic variation and morphological appearance of these species using the nuclear ribosomal ITS1-5.8S-ITS2 region sequence, we used nineteen strains collected in nature and four species of five standard strains (T. versicolor KCTC16781, KCTC26203, T. villosa KCTC06866, T. suaveolens KCTC26205 and T. hirusta KCTC26200). The data of ITS sequences indicated that nineteen strains of T. versicolor have the difference of $1{\sim}6$ base pairs, comparing with standard strains of T. versicolor KCTC16781, and KCTC26203. Phylogenetic analysis of the Trametes species showed that they grouped into a wide range of single clade. Standard strains except T. versicolor KCTC16781 and KCTC26203, formed separated subgroup.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.97-105
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• 2021

Tegillarca granosa, is one of the most important fishery resources throughout Asia. However, due to industrialization factories, marine environmental pollution, and global warming, the marine fishery production has drop sharply. In order to understand the genetic factors of the blood clam, which is a major fishery resource on the southern coast of Korea, the whole genome of blood clam was studied. The assembled genome of T. granosa was 915.4 Mb, and 19 chromosomes were identified. 25,134 genes were identified, and 22,745 genes were functionally annotated. As a result of performing gene gain and loss analysis between the blood clam genome and eight other types of shellfish, it was confirmed that 725 gene groups were expanded, and 479 gene groups were contracted. The homeobox gene cluster of blood clam showed a well-preserved genetic structure within lophotrochozoan ancestor. T. granosa genome showed high similarity between three hemoglobin genes with Scarpharca broughtonii. The blood clam genome will provide information for the genetic and physiological characteristics of blood clam adaptation, evolution, and the development of aquaculture industry.

• Journal of Life Science
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• v.24 no.11
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• pp.1174-1179
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• 2014

This research was carried out to evaluate whether gamma ray is a useful tool for breeding new strains of mushrooms. For this research, 5 mutant groups, 20 strains of Hypsizigus marmoreus, 2 strains of Lyophyllum decastes, and 1 strain of Lyophyllum shimeji were used. Monokaryon spores from one variety of H. marmoreus were irradiated with 50~2,000 Gy of gamma ray. The propriety dose was 50~200 Gy for mutagenesis. Mutant monokaryon mycelia crossed each order to become dikaryon mycelia. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR, and the products were sequenced. The sequences of the ITS regions (16 partial rDNA, complete ITS1, 5.8 rDNA and partial rDNA) were analyzed by PCR, and strains of H. marmoreus, L. decastes, and L. shimeji were auto-sequenced. The lengths of the sequenced ITSs were 1,052~1,143 nucleotides. Genetic matrices were calculated using Nei-Li's genetic distance coefficient based on ITS sequence. The dissimilarities were 0~3.35% in strains of H. Hypsizigus. In addition, a phylogenetic tree was constructed based on ITS sequences using the neighbor-joining (NJ) method. The phylogenetic tree revealed that 23 strains and 5 mutant groups were divided into 12 clusters; the mutant groups fell into different clusters. These results show that mushroom spores were mutated effectively by gamma ray; therefore, gamma ray could be a useful tool for breeding new strains of mushrooms.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.82-90
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• 2016

Most Araliaceae plant species distributed in Korea are economically important because of their high medicinal values. This study was conducted to develop barcode markers from sequence analysis of chloroplast DNA in 14 taxa of Araliaceae species grown in South Korea. Sequencing of seven chloroplast DNA regions was performed to establish the DNA barcode markers, as suggested by the Consortium for the Barcode of Life (CBOL). From the sequence analysis of chloroplast DNA, we identified specific sequences and nucleotides that allowed us to discriminate among each other 14 Korean Araliaceae species. The sequence in the region of psbA-trnH revealed the most frequent DNA indels and substitutions of all 7 regions studied. This psbA-trnH marker alone can discriminate among all 14 species. There are no differences between Korean and Chinese Panax ginseng in all seven sequenced chloroplast DNA regions. A phylogenetic tree constructed using the seven chloroplast DNA regions revealed that Tetrapanax papyriferus should be classified as an independent clade. The Aralia and Panax genera showed a close phylogenetic relationship. Five species in the Eleutherococcus genus were more closely related to Kalopanax septemlobus than to any Panax species.