• Animal Systematics, Evolution and Diversity
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• v.35 no.4
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• pp.186-190
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• 2019

DNA barcoding of two marine tintinnids, Eutintinnus rectus and Schmidingerella arcuata, was performed using four samples collected from different sites in the north-eastern coast of South Korea. The loricae morphology was observed by light and scanning electron microscopy. Molecular data were analyzed using five nuclear ribosomal DNA markers(18S, ITS1, 5.8S, ITS2, and 28S genes) and one mitochondrial marker (CO1 gene). The intraspecific pairwise differences of E. rectus and S. arcuata in the CO1 gene were 0.0-0.2% and 0.0-0.6%, respectively, while there were no differences in the 18S rDNA sequences.

• Journal of Life Science
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• v.27 no.1
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• pp.89-94
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• 2017

DNA sequences of the intergenic spacer 1 and intergenic spacer 2 of the nineteen plants belonging Vitis genus were collected from the Genbank. DNA sequences of the same regions of Vitis thunbergii var. sinuata and Ampelopsis brevipedunculata var. heterophylla, both common plants in Korea, were not available in Genbank. Those two plants were collected, their genomic DNA encoding 18S rRNA, intergenic spacer 1, 5.8S rRNA, intergenic spacer 2 and part of 28S rRNA amplified and DNA sequence determined. DNA sequences of twenty-one plants including two Korean plants were aligned by the Multiple sequence comparison by log-expectation(MUSCLE) algorithm and the alignment was used to calculate neighbor-joining tree and pairwise distance. The results indicate DNA sequences of the two Korean plants are highly homologous with each other, but they are quite distantly related to the other Vitis plants. Distant relationship of the two Korean plants with the other Vitis plants might be due to independent evolution of those two plants in geographically isolated environment. Those two Korean plants are classified in different genera based on the morphology, one in Vitis genus and the other in Ampelopsis genus, providing another example of discrepancy between morphological and genetic classification.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.421-428
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• 2003

To develop the functional-compost containing antifungal substance by using antagonistic microorganisms, Spinacia oleracea L and Rhizoctonia solani Kuhn O-28 were used as a model plant and phytopathogen, respectively. Total 80 strains were isolated from the compost of various waste foods mixture processed for a year. Among them, No.15-2 strain was selected due to its highest antifungal activity against R. solani Kuhn O-28 and was identified phyno- and phylogenotypically as Burkholderia cepacia genomovar V. which is rare probability in pathogen, by 16S rDNA sequencing and specific primer pair PCR method. B. cepacia No.15-2 preferentially dominated during the compost and its cell numbers were maintained almost $${\times}$10^{13}$ cuf/g for 15 days. The morbidity caused by R. solani Kuhn O-28 in S. oleracea L cultivation was reduced to 40% by addition of B. cepacia No.15-2. In conclusion, the antifungal compost using B. cepacia No.15-2 could be applied to biocontrol of various crops blights caused by fungal pathogen.

• Journal of Species Research
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• v.11 no.3
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• pp.162-168
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• 2022

Compared to marine dinoflagellates, freshwater species are rarely recorded in Korea. In the present study, we isolated a freshwater dinoflagellate, Palatinus, from the Paldang Reservoir, Korea, in December 2021. The overall cell shape was ovoid, and the cell size was 34.3 ㎛ in length (25.8-39.5 ㎛) and 28.4 ㎛ in width (21.5-34 ㎛). An eyespot was usually observed near the sulcal region. The Kofoidian plate formula of the species was determined to be 4', 2a, 7", 6c, 5s, 5''', and 2''''. Apical pore complex was not observed. However, variations in the cingular plate caused by the fusion of 3C and 4C were observed. Analyses of 28S rDNA sequences revealed that the unidentified species is 100% similar to Palatinus apiculatus, and clustered together in the same lineage in the phylogenetic tree (100% bootstrap value). Our findings confirmed that the isolated dinoflagellate is Palatinus apiculatus, which was discovered for the first time in Korean freshwaters.

• Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.175-183
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• 2004

The dinoflagellate Alexandrium tamiyavanichii Balech, a producer of toxins causing paralytic shellfish poisoning (PSP), has recently been considered as one of main organisms responsible for toxication of shellfish in Japan. In this study, A. tamiyavanichii was subjected to a molecular phylogenetic analysis inferred from 28S rDNA D1-D2 sequences and a species-specific LSU rRNA-targeted oligonucleotide DNA probe was designed to identify A. tamiyavanichii using the whole cell-FISH (fluorescence in situ hybridization). The sequences of the 28S rDNA D1-D2 region of A. tamiyavanichii showed no difference from A. cohorticular AF1746l4 (present name A. tamiyavanichii) and formed a distinct clade from the 'tamarensis species complex'. The probe, TAMID2, reacted specifically with A. tamiyavanichii cultured cells, without any cross-reaction with other species belonging to the same genus, including A. tamarense, A. catenella, A. affine, A. fraterculus, A. insuetum and A. pseudogonyaulax. In a test of cross-reactivity with a field sample, TAMID2 reacted consistently with only A. tamiyavanichii, indicating that the present protocol involving the TAMID2 probe might be useful for detecting toxic A. tamiyavanichii in a simple and rapid manner.

• Animal Systematics, Evolution and Diversity
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• v.34 no.4
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• pp.194-198
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• 2018

The genus Prionchulus Cobb, 1916 represents a group of predaceous nematodes belonging to the family Mononchidae Chitwood, 1937, and is found worldwide. However, only five species have been reported thus far from Korea. Prionchulus oleksandri Winiszewska and Susulovsky, 2003 is reported for the first time from Korea, from sediments collected from the Nakdong River. This species is distinguished from other Prionchulus species by its truncated lip region with small cephalic papillae and refringens vaginae. In this study, morphological characters(detailed morphometrics) of P. oleksandri are described and illustrated using optical microscopy. DNA barcode sequence information (the D2-D3 region of 28S rDNA, 18S rDNA, and internal transcribed spacer rDNA) is also provided for the molecular identification of the species.

• Parasites, Hosts and Diseases
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• v.51 no.5
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• pp.511-517
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• 2013

Species identification using DNA sequences is the basis for DNA taxonomy. In this study, we sequenced the ribosomal large-subunit RNA gene sequences (3,037-3,061 bp) in length of 13 Chinese Theileria stocks that were infective to cattle and sheep. The complete 28S rRNA gene is relatively difficult to amplify and its conserved region is not important for phylogenetic study. Therefore, we selected the D2-D3 region from the complete 28S rRNA sequences for phylogenetic analysis. Our analyses of 28S rRNA gene sequences showed that the 28S rRNA was useful as a phylogenetic marker for analyzing the relationships among Theileria spp. in ruminants. In addition, the D2-D3 region was a short segment that could be used instead of the whole 28S rRNA sequence during the phylogenetic analysis of Theileria, and it may be an ideal DNA barcode.

• Journal of Life Science
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• v.25 no.2
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• pp.243-248
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• 2015

Cirsium chanroenicum, Cirsium nipponicum, and Cirsium schantarense plants were collected from Changwon, Ulleungdo, and Dooryoon Mountain, respectively. Cirsium japonicum plants were also collected from various locations in Korea. Genomic DNA was prepared from the collected plants and used for amplification of the 18S rDNA, ITS1, 5.8S rDNA, ITS2, and part of 28S rDNA. The ITS1 and ITS2 sequences of the PCR products and from other Cirsium plants reported previously were aligned and compared. Cirsium chanroenicum, Cirsium nipponicum, and Cirsium setidens formed distinct branches on the neighbor-joining tree. Cirsium japonicum and Cirsium pendulum appeared to be close to one another, but Cirsium pendulum plants were clearly clustered in an independent clade. Cirsium shantarense was clustered with the other Cirsium japonicum plants. The most important characteristic that distinguished these two species was the direction of the flowers. All Cirsium japonicum flowers point upward, but Cirsium shantarense flowers point downward. Other than this feature, these two species are almost indistinguishable morphologically. Cirsium chanroenicum is indistinguishable morphologically from Cirsium setidens, but it still formed a distinct group on the neighbor-joining tree based on ITS sequences, suggesting that this species is worth considering as an independent species. Silymarin production of the collected plants was analyzed and appeared to be quite high, indicating that the ability to synthesize silymarin is common to all Cirsium plants analyzed so far.

• Ocean and Polar Research
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• v.28 no.2
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• pp.107-117
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• 2006

Freshwater algal studies in North polar environments are relatively few. This study presented the algal-flora, -biomass and genetic features of dominant cells collected from temporary ponds around the Polar Research Station (PRS), Norway. Water samples were collected from 4 stations around PRS, and analyzed for their environmental and biological variables. Water temperature, salinity and conductivity ranged from 5 to $10^{\circ}C$, 0.1 to $0.3%_{\circ}$ and 0.21 to $0.36{\mu}S/cm$, respectively. Chlorophyll a concentration ranged from 1.8 to $11.1{\mu}g/l$, and that of the size-fractionated cells was recorded from 0.7 to $1.1{\mu}g/l$ in picoplankton 0.3 to $6.5{\mu}g/l$ in nanoplankton, and 0.4 to $3.9{\mu}g/l$ in microplankton respectively. Algal flora in the present study was recorded as 10 genera, in which Chlamydomonas, particularly, was dominant in all studied sites. By comparison of Chlamydomonas 18S rDNA sequences, including two isolates from PRS, they formed a distinct clade against others: sequence similarity was significantly low (<97.2%) with C. noctigama, being the highest score by BLAST search in GenBank. This study was valuable for basic knowledge regarding the freshwater algae around PRS and their genetic information.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.141-150
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• 2015

Dinoflagellates are ubiquitous and important primary producers in the oceans. They have diverse trophic modes, i.e., phototrophic, heterotrophic, and mixotrophic modes and thereby, play important ecological role in marine microbial food-web. While many studies have been focused on planktonic dinoflagellates in pelagic ecosystems, benthic, sand-dwelling dinoflagellates that inhabit in intertidal zone have been very poorly documented worldwide. We investigated biodiversity, occurrence, and molecular phylogeny of benthic, sand-dwelling dinoflagellates from the intertidal flat of Dongho, west coast of Korea during low-tide, monthly from November 2012 to February 2014. About 27 species of 13 genera in orders Gonyaulacales, Gymnodiniales, Peridiniales, Prorocentrales have been identified, of which members in the genus Amphidinium constituted a major part of the sand-dwelling dinoflagellates in this area. A total of 34 isolates from 16 species of the sand-dwelling dinoflagellates were isolated from Dongho, Mohang, Gamami, and Songho in the west coast and Hyupjae in Jeju of Korea, their 28S rDNA sequences were successfully amplified, and applied for molecular phylogenetic analyses. In the 28S rDNA phylogeny, Amphidinium species diverged across three major clusters within the order Gymnodiniales and formed polyphyletic group. Based on the unambiguously aligned partial 28S rDNA sequences including variable D2 region, the genotypes of Amphidinium mootonorum Korean strains greatly differed from that of Canadian strain with 19.2% of pairwise nucleotide difference, suggesting that further ultrastructural studies may provide additional characters to clearly separate these genotypes. Two potential toxic species, Amphidinium carterae and A. operculatum appeared occasionally during this study. Quantitative assessment and toxicity of those species should be addressed in the future.