• Journal of Life Science
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• v.19 no.3
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• pp.311-316
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• 2009

The brown algae, or phaeophytes, are a large group of multicellular algae, including many notable types of seaweed. We analysed intra- and interspecific phylogenic studies within the genus Pelvetia in Korea and compared them with results of both same and different species in GenBank. The sequences for P. babingtonii in Korea were generally similar to those for P. babingtonii AF102957, and the sequences of P. siliquosa in Korea were also similar to those of P. siliquosa AF102958. Sequence variation within the Pelvetia is mostly due to nucleotide substitutions, although several small indels and some large indels can be found. Another source of sequence divergence is length variation due to stretches of short repeats that occur at the ITS1 or ITS2 in all the Pelvetia. NJ analysis consists mainly of two clades. One of them contains P. canaliculata and P. limitata, and is sister to the rest of the genus (P. siliquosa, P. compressa, and P. babingtonii). P. babingtonii is not grouped one clade. In the MP analysis, ten accessions or populations were fully resolved and all accessions from the same species formed with 99% or 100% bootstrap supports.

• Journal of Life Science
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• v.27 no.3
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• pp.351-354
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• 2017

Cowpea (Vigna unguiculata (L.) Walp.) is recognized as a potential source of protein and other nutrients. The genus Vigna includes 100 wild species of plants. Especially, Vigna unguiculata includes annual cowpeas (ssp. unguiculata) and ten wild perennial subspecies. DNA sequence of internal transcribed spacer (ITS) region was determined for Vigna sinensis, one of native plant, which was found in recent but thought to have gone extinct in Korea. The seeds of Vigna sinensis used in this study were donated from Dong-Young Jo. The DNA sequence of ITS-5.8S-ITS2 for Vigna sinensis obtained from this study was deposited as Vigna sinensis AY195581 on GenBank of NCBI (National Center for Biotechnology Information). We investigated the sequence-based phylogenetic relationships of plants related and clarified its taxonomical position. DNA similarities among subspecies including Vigna unguiculata showed the range 98 to 100% in sequence-based phylogenetic analysis using total 507 base pairs of ITS1, 5.8S and ITS2. Vigna unguiculata and subspecies were grouped independently as one cluster from other Vigna species used in the phylogenetic analysis. In this study, based on the phylogenetic analysis using the ITS1-5.8S-ITS2 sequence of Vigna sinensis, it may be concluded to be classified to one of Vigna unguiculata substrains.

• Journal of Life Science
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• v.13 no.5
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• pp.723-731
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• 2003

For the investigation of conserved regions in lipase genes, 132 and 24 sequences were obtained from LED (Lipase Engineering Database) and COG (Clusters of Orthologous Groups of proteins), respectively. There was high diversity in lipase genes and peculiar amino acid sequences were conserved for each homologous family of LED. Similar conserved amino acid sequences were detected from COG0657 and Moraxella lipase 1 homologous group of LED. Although many studies have attempted to detect new lipase genes in procaryotes, they have been limited culturable bacteria. The importance of metagenome, including DNA from non-culturable bacteria, is known. Due to the high diversity, we assumed it might be possible to detect new lipase gene from metagenome. Due to the high diversity of nucleotide sequences in lipase genes, 10 primer sets were designed. Designed primer sets were inspected in BLAST of NCBI and they could amplify a part of the lipase gene from 222 to 713 bp. They can amplify 16.7%∼60.0% of each lipase homologous group which was 3.6 fold higher than each sets. They might offer a high probability of detecting new lipase genes, owing to high efficiency and the diversity of lipase genes.

• Journal of fish pathology
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• v.30 no.2
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• pp.79-88
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• 2017

At the present, fish farms are suffering a lot of economic losses due to infectious diseases caused by various pathogens including aeromonad. Aeromonad is ubiquitous bacteria that causes infectious diseases. At least 26 species in the genus Aeromonas have been reported to cause fatal infections not only in salmonid fishes, but also in other freshwater and seawater fishes. Molecular techniques based on nucleic acid sequences of 16S rDNA and housekeeping genes can be used to identify the Aeromonas species. In this study, The genus Aeromonas was isolated from salmonid fishes of sixteen fish farms in Gangwon-Do, Korea and phylogenetically identified based on the sequences of 16S rDNA and housekeeping genes for Aeromonad, i.e. RNA polymerase sigma factor ${\sigma}^{70}$ (rpoD) or DNA gyrase subunit B (gyrB). Consequently, 96 strains were collected from Atlantic salmon (Salmo salar), coho salmon (Oncorhynchus kisutch), masou salmon (Oncorhynchus masou) and rainbow trout (Oncorhynchus mykiss), and 36 isolates were identified as the genus Aeromonas by 16S rDNA analysis. Thirty six Aeromonad isolates were further analysed based on rpoD or gyrB gene sequences and found Aeromonas salmonicida (24 isolates), A. sobria (10 isolates), A. media (1 isolates) and A. popoffii (1 isolates), indicating that A. salmonicida is a main infectious bacteria in Salmonid fishes in Gangwon-Do. It was also proved that the phylogenetic identification of Aeromonas species based on the sequences of housekeeping gene is more precise than the 16S rDNA sequence.

• Korean Journal of Plant Taxonomy
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• v.44 no.1
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• pp.22-32
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• 2014

The petal and sepal micromorphology of five species of Glechoma (Lamiaceae) was investigated to evaluate their taxonomic significance, and a molecular phylogeny using the sequences of internal transcribed spacers (ITS) regions of nuclear ribosomal DNA was carried out to resolve their phylogenetic relationships. Stomatal complexes were mostly found in the inner and outer part of the sepal from all investigated taxa, and the size length of the guard cell was variable among the taxa. Five types of trichomes (uni-cellular non-glandular trichome, multi-cellular non-glandular trichome, short-stalked capitate glandular trichome, long-stalked capitate glandular trichome, and peltate glandular trichome) were variable among the taxa as well as their distribution and density. In molecular phylogenetic studies, the genus Glechoma was composed of three geographically distinct major monophyletic groups (Europe-U.S.A., China-Korea, Japan). G. longituba in Korea and China formed well-supported monophyletic group. G. hederacea in Europe and U.S.A. formed a monophyletic and well-supported clade with G. sardoa, which are endemic species in Italy, with G. hirsuta falling as a sister to this clade. However, G. grandis did not form any phylogenetic relationships with the remaining taxa. The ITS analyses provided taxonomic boundaries of taxa in Glechoma although the petal and sepal micromorphological characters provided weak evidences of the systematic value. As further studies, incorporating more DNA regions to the matrix including other additional morphological analysis will be significant to provide clearer taxonomic structure in Glechoma.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.229-236
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• 2020

Sixty-five molds isolated from clinical specimens were included in this study. All the isolates were molds that could be identified morphologically, strains that are difficult to identify because of morphological similarities, and strains that require species-level identification. PCR and direct sequencing were performed to target the internal transcribed spacer (ITS) region, the D1/D2 region, and the β-tubulin gene. Comparative sequence analysis using the GenBank database was performed using the basic local alignment search tool (BLAST) algorithm. The fungi identified morphologically to the genus level were 67%. Sequencing analysis was performed on 62 genera and species level of the 65 strains. Discrepancies were 14 (21.5%) of the 65 strains between the results of phenotypic and molecular identification. B. dermatitidis, T. marneffei, and G. argillacea were identified for the first time in Korea using the DNA sequencing method. Morphological identification is a very useful method in terms of the reporting time and costs in cases of frequently isolated and rapid growth, such as Aspergillus. When molecular methods are employed, the cost and clinical significance should be considered. On the other hand, the molecular identification of molds can provide fast and accurate results.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.334-340
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• 1998

This research was conducted to identify plant regulatory regions by gene tagging method. A promoterless GUS coding sequence was introduced to Populus nigra ${\times}$ P. maximowiczii via Agrobacterium strains(LBA4404/EHA101), and putative transgenic poplars were selected by culturing on medium containing G418($60mg/{\ell}$) and by GUS assay. Among them one positive plant was to amplify the native sequences flanking to the introduced GUS gene in plant genome by inverse PCR method and from this 730 by DNA product was obtained. After subcloning and sequencing, it has 88% homology to the Eucalyptus gunnii CAD(cinnamyl alcohol dehydrogenase) gene. The GUS gene fused with the putative promoter reinserted into poplar leaves by particle bombardment method to test the funtional promoter activity. Upon staining with X-gluc, many blue spots appeared on the leaf segments bombarded by the chimeric gene 2-3 days, thus the isolated DNA fragment contain some possible coding region as well as a putative regulatory sequences of poplar CAD gene.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.205-210
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• 1999

16brio cholerne is an important pathogenic organism that causes dimhea in human beings. V ciaoleroe KNIH002 was isolated from patients suffering with dian.heal disease in Korea. From Southern hybridization using the amplified PCR product of 307 bp as a probe. which was obtained from PCR reaction using primer detecting cholera toxin gene, we have found that the c b gene located in 4.5-kb fragmenl double digested with Pstl and BgllI of the chromosome. Therefore, we made mini-libraries of the isolate using PstI and Bgm restriction endonuclease and pBluescript SKU(+) vector. As a result. we cloned 4.5-kb PstI-BglII fragment containing the c a gene encoding a cholera toxin from the constructed mini-libraries of V olzolerae KNlH002 by colony hybridization using the same probes. This recombinant plasmid was named pCTX75. E. coii XL1- Blue harboring pCTX75 showed the cytotoxicity on Chinese Hamster Ovary cells. From the sequencing of he cloned recombinant plasmid, we confinned that it has virulence gene cassette consisting of ace, zot, ctx.4 and cf"~B gene. The ace and zot genes were composed of 291 hp and 1.200 bp with ATG initiation codon and TGA lennination codon, respectively. Nucleotide sequence of the ace gene exhibited 100% identity with that of V cholera E7946 El Tor Ogawa strains. But, nucleolide and amino acid sequence comparison of the zot gene exhibited 99% and 98.8% identity with that of V cholerae 395 Classical Ogawa stram, respectively. Specially. the Ala-100, Ala-272 and Ala-281 sites of Zoi polypeptide presented in V choleme 395 Classical Ogawa strain are replaced by Val in V cholerae KNIH002.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.366-374
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• 2010

Culture-dependent RFLP and culture-independent DGGE were employed to investigate the bacterial community associated with the marine sponge Spirastrella abata. A total of 164 bacterial strains associated with the sponge were cultivated using Zobell and Natural sea salt media. PCR amplicons of the 16S rDNA from the bacterial strains were digested with the restriction enzymes HaeIII and MspI, and then assigned into different groups according to their restriction patterns. The 16S rDNA sequences derived from RFLP patterns showed more than 95% similarities compared with known bacterial species, and the isolates belonged to four phyla, Proteobacteria (Alphaproteobacteria, Gammaproteobacteria), Actinobacteria, Firmicutes, and Bacteriodetes, of which Alphaproteobacteria was dominant. DGGE fingerprinting of 16S rDNAs amplified from the sponge- derived total gDNA showed five major DGGE bands, and their sequences showed more than 96% similarities compared with available sequences. The sequences derived from DGGE bands revealed high similarity with the uncultured bacterial clones. DGGE revealed that bacterial community consisted of four phyla, including Proteobacteria (Alphaproteobacteria, Gammaproteobacteria), Actinobacteria, Spirochetes, and Chloroflexi. Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria were commonly found in bacteria associated with S. abata by both RFLP and DGGE methods; however, overall bacterial community in the sponge differed depending on the analysis methods.

• Journal of Life Science
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• v.22 no.8
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• pp.1120-1125
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• 2012

Cirsium pendulum plants were collected from Hongcheon, Pyeongchang, Wonju, Yangyang in Kangwondo, Gapyeong in Gyeongkido, and Choongju in Choongcheongbukdo. Cirsium setidens plants were collected from Taebaek in Kangwondo and Bonghwa in Kyeongsangbukdo. Genomic DNA was prepared from those plants and used for the amplification of 18S rDNA, ITS1, 5.8S rDNA, ITS2, and part of 28S rDNA. The PCR products were sequenced, and the sequence was deposited in the GenBank. The comparison of those sequences has revealed that the rDNA sequences are identical for all six C. pendulum plants, but that the ITS1 and ITS2 sequences contain variable nucleotides. The two C. setidens plants had different nucleotides in 18S rDNA, ITS1, and ITS2. The comparison of the DNA sequences of C. pendulum and C. setidens collected in this study with C. pendulum of Hokkaido in Japan and C. japonicum of Anhui in China indicated that the plants of those three species are clearly divided into three distinct groups. The silymarin content of the collected plants was analyzed and turned out to be quite high. Therefore, it has been found that both C. pendulum and C. setidens plants are producing large amounts of silymarin, which has been reported to have various medicinal effects.