• ALGAE
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• v.31 no.3
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• pp.219-230
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• 2016

The Euglena deses group are common freshwater species composed of E. adhaerens, E. carterae, E. deses, E. mutabilis, and E. satelles. These species are characterized by elongated cylindrical worm-like cell bodies and numerous discoid chloroplasts with a naked pyrenoid. To understand the cryptic diversity, species delimitation and phylogenetic relationships among members of the group, we analyzed morphological data (light and scanning electron microscopy) and molecular data (nuclear small subunit [SSU] and large subunit [LSU] rDNAs and plastid SSU and LSU rDNAs). Bayesian and maximum likelihood analyses based on the combined four-gene dataset resulted in a tree consisting of two major clades within the group. The first clade was composed of two subclades: the E. mutabilis subclade, and the E. satelles, E. carterae, and E. adhaerens subclade. The E. mutabilis subclade was characterized by a lateral canal opening at the anterior end and a single pellicular stria, whereas the E. satelles, E. carterae, and E. adhaerens subclade was characterized by an apical canal opening at the anterior end of the cell and double pellicular striae. The second clade consisted of 20 strains of E. deses, characterizing by a subapical canal opening at the anterior end and double pellicular striae, but they showed cell size variation and high genetic diversity. Species boundaries were tested using a Bayesian multi-locus species delimitation method, resulting in the recognition of five cryptic species within E. deses clade.

• The Journal of Fisheries Business Administration
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• v.45 no.2
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• pp.61-72
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• 2014

This study aimed to empirically investigate the applicability of ecosystem-based TAC (Total Allowable Catch) fisheries management targeting the large purse seine fishery where multi-species are regulated by TAC. Using a linear programming, the optimal fishing effort and the catch amount by species which maximize fishing profits were analyzed under the constraint condition of catch limits by species. Analytical results showed that an application of TAC on only chub mackerel would have negative impacts on fish stocks such as hairtail and jack mackerel by increasing the level of fishing effort to achieve its allocated catch limit. However, under the constraint condition of catch limits of all species, it was shown that optimal catches of all species were achieved within their catch limits. It implies the importance of ecosystem-based management considering biological and technical interactions of species those were excluded in the traditional single species fisheries management.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.1
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• pp.32-41
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• 2021

South Korea presently harbors less than 800 long-tailed gorals (Naemorhedus caudatus), an endangered species. I report for the first time on the taxonomic status and genetic diversity of the Korean species using non-invasive fecal sampling based on mitochondrial cytochrome b gene sequence analyses. To determine the taxonomic status of this species, I reconstructed a consensus neighbor-joining tree and generated a minimum spanning network combining haplotype sequences obtained from feces with a new goral-specific primer set developed using known sequences of the Korean goral and related species (e.g., Russian goral, Chinese goral, Himalayan goral, Japanese serow, etc.). I also examined the genetic diversity of this species. The Korean goral showed only three different haplotypes. The phylogenetic tree and parsimony haplotype network revealed a single cluster of Korean and Russian gorals, separate from related species. Generally, the Korean goral has a relatively low genetic diversity compared with that of other ungulate species (e.g., moose and red deer). I preliminarily showcased the application of non-invasive fecal sampling to the study of genetic characteristics, including the taxonomic status and genetic diversity of gorals, based on mitochondrial DNA. More phylogenetic studies are necessary to ensure the conservation of goral populations throughout South Korea.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.352-358
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• 2018

This study aimed to develop a species identification method for the egg and fry of the three Korean bitterling fishes (Pisces: Acheilognathinae), including Acheilognathus signifer, Acheilognathus yamatsutae and Rhodeus uyekii based on the PCR-based Restriction Fragment Length Polymorphism (RFLP) markers. We conducted a field survey on the Deokchicheon River from the North Han River basin, where the three Acheilognathinae species co-occur, and also analyzed the existing sequence dataset available from the GenBank. We found coexistence of the three species at the study site. The egg and fry were obtained from the host mussels (Unio douglasiae sinuolatus) by hand from May to June 2015 and in May 2017. To develop PCR-based RFLP markers for species identification of the three Acheilognathinae fish species, restriction enzymes pinpointing species-specific single nucleotide variation (SNV) sites in mitochondrial DNA COI (cytochrome oxidase I) and cyt b (cytochrome b) genes were determined. Genomic DNA was extracted from the egg and fry and RFLP experiments were carried out using restriction enzymes Apal I, Stu I and EcoR V for A. signifer, A. yamatsutae and R. uyekii, respectively. Consequently, unambiguous discrimination of the three species was possible, as could be seen in DNA band patterns from gel electrophoresis. Our developed PCR-based RFLP markers will be useful for the determination of the three species for the young and would assist in studying the spawning patterns and reproductive ecology of Acheilognathinae fishes. Furthermore, we believe the obtained information will be of importance for future maintenance, management and conservation of these natural and endangered species.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.97-104
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• 2008

Comparative study of retinal structure in two Korean endemic freshwater fishes, Zacco koreanus and Pseudobagrus koreanus, was carried out by light and scanning electron microscopy. In the visual cell layer comprised of cone cells and rod cells, the cone cells showed a distinct difference between both species. Z. koreanus had two types of cone cells, single cone cells including a long single and short single cone cells, and double cone cells, whereas P. koreanus had only one type of single cone cells having no its short single and long single cones. Meanwhile, the cone cells of Z. koreanus were arranged in more compact-rowed pattern, but it was more loose and irregular in P. koreanus. Based on field observation, Z. koreanus is mainly a epipelagic or sometimes benthopelagic and a diurnal fish with a round and large eye, while P. koreanus is a demersal and nocturnal fish with an oval and small eye. Therefore, the difference in the retinal structure of two species seems to be closely related to their ecological habitats.

• Journal of Species Research
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• v.6 no.1
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• pp.15-24
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• 2017

During the extensive survey of the prokaryotic species diversity in Korea, bacterial strains belonging to Betaproteobacteria and Epsilonproteobacteria were isolated from various sources including freshwater, sediment, soil and fish. A total of 23 isolates were obtained, among which 22 strains were assigned to the class Betaproteobacteria and one strain to the class Epsilonproteobacteria. The 22 betaproteobacterial strains were further assigned to Comamonadaceae (11 strains), Burkholderiaceae (6 strains), Oxalobacteraceae (2 strains), Neisseriaceae (1 strain) and unclassified family groups (2 strains). For the strains of Burkholderiaceae, 3 strains were identified as 3 species of Burkholderia, and 2 strains were as 2 species of Cupriavidus. For the strains of Comamonadaceae, 4 strains were identified as 2 species of the genus Hydrogenophaga, 2 strains as 2 species of Acidovorax, 2 strains as 2 species of Limnohabitans, and each of the remaining strains as single species of Comamonas, Curvibacter and Rhodoferax, respectively. For the strains of Oxalobacteraceae, 1 strain was identified as a species of Undibacterium, and the other strain as a species of Herbaspirillum. The strain belonging to Neisseriaceae was identified as a species of Iodobacter. The remaining strains of Betaproteobacteria were identified as species of Sphaerotilus and Methylibium respectively (family unassigned). The epsilonproteobacterial strain was identified as a species of Arcobacter of the family Camplyobacteraceae. The detailed description of each unrecorded species is provided.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.644-668
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• 2019

Dysphania ambrosioides (L.) Mosyakin & Clemants which belongs to Chenopodiaceae/Amaranthaceae sensu in APG system has been known as a useful plant in various fields as well as an invasive species spreading all over the world. To understand its phylogenetic relationship with neighbour species, we completed chloroplast genome of D. ambrosioides collected in Korea. Its length is 151,689 bp consisting of four sub-regions: 83,421 bp of large single copy (LSC) and 18,062 bp of small single copy (SSC) regions are separated by 25,103 bp of inverted repeat (IR) regions. 128 genes (84 protein-coding genes, eight rRNAs, and 36 tRNAs) were annotated. The overall GC content of the chloroplast genome is 36.9% and those in the LSC, SSC and IR regions are 34.9%, 30.3%, and 42.7%, respectively. Distribution of simple sequence repeats are similar to those of the other two Dysphania chloroplasts; however, different features can be utilized for population genetics. Nucleotide diversity of Dysphania chloroplast genomes 18 genes including two ribosomal RNAs contains high nucleotide diversity peaks, which may be genus or species-specific manner. Phylogenetic tree presents that D. ambrosioides occupied a basal position in genus Dysphania and phylogenetic relation of tribe level is presented clearly with complete chloroplast genomes.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.61-70
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• 2000

The purpose of this study is to identify the proper species of turf and the ground structure for the turf sports grounds. Analysis items are particle distribution of sand and gravel, saturated hydraulic conductivity, soil hardness, and turf growth. Results of this study are as follows. 1)The particle distribution of sand used in the multi-layer rootzone is within the upper limit of the standard level. The diameter of mid-size grain({TEX}$D_{50}${/TEX})was 0.62mm and the value of uniformity ({TEX}$D_{90}${/TEX}/{TEX}$D_{10}${/TEX}) was 3.93. The particle size distribution of sand used in the single-layer rootzone was beyond the standard level as {TEX}$D_{50}${/TEX})=0.86 and {TEX}$D_{90}${/TEX}/{TEX}$D_{10}${/TEX}=8.86. 2) Saturated hydraulic conductivity of the sand was higher in the multi-layer rootzone than in the single-layer rootzone while bulk density was vice versa. 3) Surface hardness was high on Kentucky bluegrass+perennial ryegrass compared to zoysiagrass probably caused by root density. 4) Visual covering and visual rating were highly evaluated on zoysiagrass within summer while better evaluated on Kentucky bluegrass+perennial ryegrass throughout fall to spring. 5) Visual color was better evaluated on Kentucky bluegrass+perennial ryegrass than on zoysiagrass throughout the year. These studies are demanded urgently according to increase in interest in the ground and turf species of the turf sports ground because of World Cup 2002.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.197-210
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• 2014

Single nucleotide polymorphisms (SNPs) are widely acknowledged as the marker of choice for many genetic and genomic applications because they show co-dominant inheritance, are highly abundant across genomes and are suitable for high-throughput genotyping. Here we evaluated the applicability of SNP markers developed from Crassostrea gigas and C. virginica expressed sequence tags (ESTs) in closely related Crassostrea and Ostrea species. A total of 213 putative interspecific level SNPs were identified from re-sequencing data in six amplicons, yielding on average of one interspecific level SNP per seven bp. High polymorphism levels were observed and the high success rate of transferability show that genic EST-derived SNP markers provide an efficient method for rapid marker development and SNP discovery in closely related oyster species. The six EST-SNP markers identified here will provide useful molecular tools for addressing questions in molecular ecology and evolution studies including for stock analysis (pedigree monitoring) in related oyster taxa.

• Journal of Microbiology
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• v.38 no.1
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• pp.11-17
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• 2000

A new method was developed for the rapid analysis of diverse bacterial species in the natural environment. Our method is based on PCR-single-strands-conformation polymorphism (PCR-SSCP) and selective isolation technique of single-stranded DNA. Variable V3 fragments of 16S rDNA were amplified by PCR with bacterial 16S rDNA primers, where one of the primers was biotinylated at the 5'-end. The biotinylated strands of the PCR products were selectively isolated by using streptavidin paramagnetic particles and a magnetic stand, to prevent SSCP analysis producing heteroduplexes from heterogeneous DNA samples. The selected strands were separated by electrophoresis on a polyacrylamide gel, and detected by silver staining. Analysis of PCR products from 8 bacterial strains demonstrated their characteristic DNA band patterns. In addition, changes in the structure of the bacterial community and species diversity in the microcosm treated with phenol could be monitored. After 3 weeks of incubation, phenol and its intermediate, 2-hydroxy-muconic-semialdehyde, were degraded by indigenous bacteria. These dominating bacterial populations were identified as strong bands on an SSCP gel. Therefore, this study provides useful tools for microbial community analysis of natural habitats.