• Journal of Microbiology
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• v.44 no.1
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• pp.83-91
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• 2006

The sudden appearance and potential lethality of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) in humans has resulted in a focusing of new attention on the determination of both its origins and evolution. The relationship existing between SARS-CoV and other groups of coronaviruses was determined via analyses of phylogenetic trees and comparative genomic analyses of the coronavirus genes: polymerase (Orflab), spike (S), envelope (E), membrane (M) and nucleocapsid (N). Although the coronaviruses are traditionally classed into 3 groups, with SARS-CoV forming a $4^{th}$ group, the phylogenetic position and origins of SARS-CoV remain a matter of some controversy. Thus, we conducted extensive phylogeneitc analyses of the genes common to all coronavirus groups, using the Neighbor-joining, Maximum-likelihood, and Bayesian methods. Our data evidenced largely identical topology for all of the obtained phylogenetic trees, thus supporting the hypothesis that the relationship existing between SARS-CoV and group 2 coronavirus is a monophyletic one. Additional comparative genomic studies, including sequence similarity and protein secondary structure analyses, suggested that SARS-Co V may bear a closer relationship with group 2 than with the other coronavirus groups. Although our data strongly suggest that group 2 coronaviruses are most closely related with SARS-CoV, further and more detailed analyses may provide us with an increased amount of information regarding the origins and evolution of the coronaviruses, most notably SARS-CoV.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.148-151
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• 2004

This study was carried out to elucidate phylogenetic relationship of a yellow lump, Phellinus linteus by comparing the nuclear ribosomal intergenic spacer (IGS) I region with that of other genera of basidiomycetes retrieved from Genbank. IGS I region of Phellinus linteus was 730 bp long and sequence homology was conserved in the 5' region, in particular $1{\sim}280\;bp$, and decreased in the direction toward the 3' end. ITS region was widely studied in phylogenies related to basidiomycetes, but IGS region was not well understood yet. Our study indicated that IGS region can be a good tool in phylogenetic study of basidiomycetes.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1110-1114
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• 2005

Six viruses of the genera Carlavirus (Garlic mosaic virus, GarMV, and Garlic latent virus, GarLV), Allexivirus (Garlic virus X, GarV-X, and Garlic mite-borne filamentous virus, GarMbFV) and Potyvirus (Leek yellow stripe virus, LYSV, and Onion yellow dwarf virus, OYDV) from Korean garlic plants with mosaic symptoms were simultaneously detected by multiplex RT-PCR and subsequently sequenced. An immunocapture RT-PCR for the detection of GarLV, LYSV, and OYDV was also performed. The coat protein phylogenetic analysis of the garlic viruses showed that the Korean isolates were most closely related to the isolates from China, Japan, Brazil, and Argentina. This study is the first report for the differentiation of six garlic viruses in Korea by simultaneous detection using multiplex RT-PCR.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.429-434
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• 2003

The 16S rDNA sequences of nine strains, two type strains of validated Microbispora species and a strain of invalidated Microbispora species, and six soil isolates, were determined and compared with those of representatives of the family Streptosporangiaceae. The phylogenetic analysis indicated that all of the validated species of the genus Microbispora consistently formed a monophyletic unit and were well separated from the other genera of the family Streptosporangiaceae. All the isolates were placed to the genus Microbispora, whereas an invalidated Microbispora species, Microbispora griseoalba IMSNU $22049^{T}$ (= KCTC $9314^{T}$), was closely related to members of the genus Nocardia.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.189-196
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• 2009

Bacteria were isolated from roots of plants belonging to family Solanaceae and Gramineae, inhabited in Dokdo island. Fifty six endospore-forming bacteria grown on tryptic soy broth (TSB) agar medium and 23 nitrogen-fixing bacteria (NFB) grown on nitrogen free agar medium were isolated, respectively. The isolates were partially identified by analyzing the 16S rDNA and categorized into phylogenetic groups. The 16S rDNA sequences of each identified isolates were compared with sequences of each type strains to analyze phylogenetic relationship by phylogenetic tree. As a result, endospore-forming bacteria and nitrogen-fixing bacteria were classified into 4 and 6 lineage groups, respectively. Among these isolated, 18 were presumed to be novel species candidates based on the similarity (lower than 98%) analysis of the l6S rDNA sequences.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.1
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• pp.72-78
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• 2014

We investigated the molecular phylogeny and genetic differences among local populations of Korean Hemiculter fishes based on their mitochondrial cytochrome b gene sequences. Our results indicated that Hemiculter leucisculus populations in China were clearly divided into two groups. The first group (Group 1) included the populations of the Yangtze River and its surrounding areas (including the Qiantangjiang, Lingjiang, Jiulongjiang, and Minjiang rivers); the second group (Group 2) contained local populations from southern China (including the Nanliujiang, Zhujiang, Wanquanhe, Qianjiang, and Nandujiang rivers). The Korean Hemiculter eigenmanni differed in its cytochrome b gene sequence by 0.6-1.0% from the Chinese H. leucisculus (Group 1), which inhabited the Yangtze River and its surrounding areas, suggesting they were phylogenetically close and likely to be the same species. The Korean H. leucisculus differed from the Chinese H. leucisculus (both Groups 1 and 2) by 8.1-9.5%, indicating a very distant phylogenetic relationship; however, the Korean H. leucisculus differed from Hemiculter bleekeri by only 0.5-0.7%, showing intraspecific nucleotide differences. We conclude that the taxonomic relationship between the Korean H. leucisculus and H. bleekeri requires further investigation using type specimens.

• Korean Journal of Veterinary Service
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• v.36 no.1
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• pp.23-30
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• 2013

An avian rotavirus (AvRV-2) was isolated from feces of broilers suffering from acute gastroenteritis in 2011. It was the first avian rotavirus isolated in Korea. To investigate the molecular characteristics of AvRV-2, the VP4, VP6, VP7 and NSP4 gene nucleotide sequences were determined and compared with those of rotavirus strains available in the GenBank database. The phylogenetic tree of VP7 gene showed that AvRV-2 had a high degree of nucleotide sequence homology (93.4% to 94.7%) with those of rotaviruses belonging to genotype G19 cluster. The phylogenetic tree of the VP4 gene revealed a high degree of nucleotide sequence homology (95.8% to 95.9%) with genotype P[30] rotaviruses isolated from chickens. The VP6 and NSP4 gene nucleotide sequences showed the highest identities with those of avian strains with 95.3% to 96.4% and 90.3% to 92.2%, respectively. Genetic characterization of the VP4, VP6, VP7 and NSP4 showed that AvRV-2 strain was most closely related to chicken rotavirus strains from Germany and Japan. Comparative nucleotide sequences and phylogenetic analysis indicated that avian rotavirus isolated from broilers belonged to genotype G19P[30] and it was the first report on avian rotavirus infection in Korea.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.400-405
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• 1986

We have constructed a phylogenetic tree for eleven species by comparing their tRNA sequences. The tree suggests that prokaryotes diverged very early before the emergence of animals. The fact that H. volcano, an archaebacterium, clusters with eukaryotes implied that eukaryotes did not diverge directly from thier common ancestor with eubacteria. The branching order of phage $T_{4}$ and phage $T_{5}$ indicates that they have diverged separately from thier hosts and they might have evolved independently. A correlation between nucleotide substitution in tRNAs and paleontological record was observed. We verified that our phylogenetic tree fits very well with traditional ones very well by imposing the molecular clock on the tree.

• International Journal of Oral Biology
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• v.38 no.1
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• pp.29-36
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• 2013

Mitis group streptococci (MGS) were classified based on the nucleotide sequences 16S rRNA gene (16S rDNA) and comprised 13 Streptococcus species. However, 16S rDNA homogeneity among MGS was too high to discriminate between clinical strains at the species level, notably between Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, and Streptococcus pseudopneumoniae. The purpose of this study was to discriminate between 37 strains of MGS isolated from Korean oral cavities using phylogenetic analysis of the DNA-dependant RNA polymerase beta-subunit gene (rpoB). 16S rDNA and rpoB from clinical strains of MGS were sequenced using the dideoxy chain termination method and analyzed using MEGA version 5 software. The resulting phylogenetic data showed that the rpoB sequences could delineate clinical strains of MGS at the species level. Phylogenetic analysis of rpoB is therefore a useful approach for identifying MGS at the species level.

• ALGAE
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• v.22 no.1
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• pp.1-10
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• 2007

To gain insights into the phylogenetic relationships of genus Staurastrum and Staurodesmus, we analyzed nuclearencoded small subunit rDNA of 82 strains, and chloroplast atpB gene sequences of 44 strains belonging to three genera (Staurastrum, Staurodesmus, Cosmarium). Excluding the Staurastrum muticum and S. orbiculare, forty five strains of genus Staurastrum formed a well supported clade. It was shown that with no cell wall sculpture and processes, these two species have a strong phylogenetic relationship with genus Staurodesmus. Therefore, it is strongly recommended to transfer Staurastrum without processes and cell wall sculpture into Staurodesmus. S. obsoletus is a taxa that is transferred from Cosmarium. But, from this study, it has shown a phylogenetic relationship with Cosmarium. Therefore, this species is strongly recommended to transfer back to Cosmarium instead of Staurodesmus. As it was studied before, genus Staurastrum has shown monophyletic. Since the genus taurodesmus groups with Cosmarium, they were shown to be polyphyletic.