• Korean Journal of Ornithology
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• v.25 no.2
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• pp.117-125
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• 2018

The Grey-capped greenfinch (Chloris sinica) is a polytypic species that exhibits complicated geographical variation in morphology. This study provides an intraspecific phylogeographic variability of C. sinica populations in Korea with their morphometric data. The observed morphometric variations were that Ulleung island population was morphologically distinct in bill length and depths as compared to the mainland populations. Phylogenetic relationships among mitochondrial COX1 regions provided evidence for genetic differentiation between Ulleung and mainland populations. However, their genetic distances and nucleotide diversities were very low, highlighting their recent divergence. The needs for additional research is heightened to substantiate if the genetic clines in different localities may arise in C. sinica subspecies, each of which could have different breeding and wintering habitats, distribution patterns, and migration pathways.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.318-327
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• 2007

This study presents the molecular phylogenetic analysis of Korean Aurelia aurita Linnaeus collected from Yeosu in the southern waters of Korea using nuclear ITS1 region and mitochondrial COI gene sequences. The use of oligonucleotide primers F5 (forward) and R5 (reverse) targeted to ITS1 and LCO1490 (forward) and HCO2198 (reverse) targeted to COI amplified 267 bp and 643 bp fragments, respectively. The shortest genetic distance towards the ITS1 region is estimated at 0.023 when comparing Korean A. aurita to Aurelia sp. collected from California, USA. In particular, Korean and American/Swedish A. aurita were located far away in terms of genetic distance, ranging from 0.393 to 0.395. On the other hand, the genetic distance between Korean and English/Turkish/Swedish/American A. aurita regarding the mitochondrial DNA COI gene ranged from 0.201 to 0.205. However, a sister-ship with Korean and American A. aurita showed an extremely high bootstrap value (100%). The predicted secondary RNA structure of the mitochondrial DNA COI gene showed many different folding structures with a similar energy between Korean and American A. aurita. These results suggest that ITS1 and the mitochondrial DNA COI gene could be used as genetic markers for identification of the biogeographic populations.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.189-195
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• 2006

We investigated the genetic variation in Stewartia koreana Nakai by examining 61 I-SSR amplicons in 120 individuals distributed among six natural populations in Korea. The overall percentage of polymorphic I-SSR amplicons was 81.9% and mean number of amplicons per I-SSR primer was 12.2. Levels of genetic diversity within 6 populations were similar each other[Shannon's Index $0.358{\sim}0.467$(mean: 0.407)]. The Mt. Obong population had the highest level of genetic diversity and was most distinctive from the other populations. Most variation existed among individuals within population(88.2%). Genetic differentiation among populations(${\phi}_{ST}$) was 0.118. The UPGMA dendrogram based on the genetic distance failed in showing decisive geographic relationships.

• Korean Journal of Plant Taxonomy
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• v.42 no.3
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• pp.215-221
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• 2012

Five Korean Calanthe species, C. discolor, C. bicolor, C. sieboldii, C. reflexa, and C. aristulifera, were studied using amplified fragment length polymorphism (AFLP) to assess their taxonomic and genetic relationships. Sixteen accessions belonging to five native Calanthe spp. and mutants with yellow tepal and white lip (YW mutants) were studied. We identified 50 putative markers using AFLP analysis. The results of AMOVA showed that genetic variance was higher between species than within species. Genetic dissimilarity when compared with the rest of the species was the lowest for individuals of the YW mutants and the highest for individuals of C. reflexa. The mutants clustered outside the major group. Calanthe bicolor clustered with C. discolor, suggesting that its genetic composition is closer to that of C. discolor. Though it is suggested to have originated as a result of natural hybridization between C. sieboldii and C. discolor, introgression is likely to have occurred in the direction of C. discolor based on the data of molecular marker, clustering and genetic dissimilarity. Calanthe reflexa and C. aristulifera were genetically the most diverse of the species studied. In conclusion, the results showed that there is genetic diversity in Korean Calanthe species, that C. bicolor introgressed in the direction of C. discolor and that the YW mutants are genetically closer to C. sieboldii.

• Journal of Life Science
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• v.25 no.12
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• pp.1347-1353
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• 2015

The fleshy shrimp, Fenneropenaeus chinensis, is the family of Penaeidae and one of the most economically important marine culture species in Korea. However, its genetic characteristics have never been studied. In this study, a total of 240 wild F. chinensis individuals were collected from four locations as follows: Narodo (NRD, n = 60), Beopseongpo (BSP, n = 60), Chaesukpo (CSP, n = 60), and Cheonsuman (CSM, n = 60). Genetic variability and the relationships among four wild F. chinensis populations were analyzed using 13 newly developed microsatellite loci. Relatively high levels of genetic variability (mean allelic richness = 16.87; mean heterozygosity = 0.845) were found among localities. Among the 52 population loci, 13 showed significant deviation from the Hardy–Weinberg equilibrium. Neighbor-joining, principal coordinate, and molecular variance analyses revealed the presence of three subpopulations (NRD, CSM, BSP and CSP), which was consistent with clustering based on genetic distance. The mean observed heterozygosity values of the NRD, CSM, BSP, and CSP populations were 0.724, 0.821, 0.814, and 0.785 over all loci, respectively. These genetic variability and differentiation results of the four wild populations can be applied for future genetic improvement using selective breeding and to design suitable management guidelines for Korean F. chinensis culture.

• Korean Journal of Ichthyology
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• v.21 no.2
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• pp.76-80
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• 2009

Genetic diversity and genetic structure within the Geum River and Mankyung River populations of the Korean endangered Black shinner (Pseudopungtungia nigra) were assessed by amplified fragment length polymorphism (AFLP). AFLP analysis using five primer combinations generated 447 AFLP bands with 64.1% polymorphism (Geum River 74.6% and Mankyung River 53.6%). The heterozygosities within the two populations were calculated to be 0.170 and 0.104, respectively. Their average genetic diversities are 0.240 and 0.147, respectively. The pairwise Fst value (0.150) indicated distinct genetic differentiation between the two populations. A UPGMA dendrogram based on genetic distance among the individuals revealed a division corresponding to geographical regions, with low genetic variation within the Mankyung River population, and low genetic distance (0.026) between the two populations. Consequently, the two populations may have the same genetic origin The Geum River population will be more suitable than the Mankyung River population for conservation plans to increase the population sizes. Genetic and habitat management will be necessary for the Mankyung River population.

• Journal of Animal Science and Technology
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• v.52 no.2
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• pp.97-102
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• 2010

The objective of this study was to examine the suitability of genetic evaluation models using the integrated racing records collected from Gwacheon and Busan Gyeongnam racetracks. Results obtained are summarized as follows: In the short-distance races of 1,400 meters and less the records of finishing time at Gwacheon racetrack was superior, whereas, in the races of 1,800 meters and more it was superior in the records from Busan Gyeongnam racetrack. The effects of contemporary groups accounted for 42.7~70.2% of the total variation, and the effects of the individual race considering racing classes was the biggest in all racing distances. Heritabilities and repeatabilities for the finishing time were estimated in the range of 0.153-0.238 and 0.401-0.498, respectively. Correlation coefficients between the breeding values estimated from the integrated records and the breeding values estimated from records of Gwacheon and Busan-Gyeongnam were 0.907 and 0.803, and coefficients of rank correlations were 0.891 and 0.846, respectively. The correlation coefficients between sire's annual earning of the integrated records and Gwacheon and Busan Gyeongnam racetracks records were 0.943 and 0.886, and coefficients of rank correlations were 0.938 and 0.853, respectively. Also, the correlation coefficient of sire's annual earning between Gwacheon and Busan Gyeongnam racetracks was 0.742. The results of this analysis indicate that the genetic evaluation using the integrated racing records are reliable when the racing records from Busan Gyeongnam racetracks are stabilized and more data are accumulated.

• Korean Journal of Ecology and Environment
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• v.53 no.3
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• pp.265-274
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• 2020

Silver croaker (Pennahia argentata) is a turbulent species that is widely distributed worldwide and is mainly found in the bottom of the ocean. In the study, we characterized the cytochrome c oxidase subunit I (COI) gene of the mitochondrial DNA (mtDNA) on P. argentata inhabiting Gwangyang Bay and analyzed the phylogenetic location of marine fish species. As a result of multiple arrangement of 605 bp COI sequences, high homology of mtDNA nucleotide sequences was confirmed in the silver croakers from Gwangyang Bay (98~100%). However, the nucleotide variation was different according to the catching points of the inland and the open seas of Gwangyang Bay. The nucleotide sequence variation in COI was high in P. argentata from the open seas of Gwangyang Bay (43.2~70.3%). Furthermore, the phylogenetic analysis of 13 fish showed that P. argentata from Gwangyang Bay were grouped into one clade with P. argentata reported in Taiwan, and the evolutionary distance was 0.036. In addition, it was identified that the evolutionary distance was close to that of fish belonging to the Mi-iuy croaker (Miichthys miiuy) and the Big-head pennah croaker (Pennahia Macrocephalus) (0.041~0.048). The result of these studies will be used as the key genetic information for fisheries resources monitoring and species diversity management according to the coastal environment.

• Journal of Life Science
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• v.20 no.3
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• pp.336-344
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• 2010

To assess population structure and genetic diversity among the Pacific cod (Gadus macrocephalus), we investigated mtDNA COI gene sequences of 7 populations. Samples were obtained from Sokcho, Wolsung, Geojedo, Yeosu, Geomundo and Westsouth in 2008 and 2009 (n=28). The sequence analysis of 28 individual samples showed 8 haplotypes, ranging in sequence divergence by pairwise comparisons from 0.2 to 2.2% (1 bp-11 bp). The Gal haplotype was found in Wolsung, Geojedo, Yeosu, Geomundo and Westsouth, and was regarded as the main haplotype of Korean Pacific cod. Ga2, Ga3, Ga6 and Ga7 haplotypes were found only in Sokcho. In the PHYLIP analysis, 8 haplotypes formed two independent groups: cladeA consisted of Ga2, Ga3, Ga6 and Ga7 haplotypes, whereas cladeB contained Gal, Ga4, Ga5 and Ga8 haplotypes. The genetic relationship between the two groups was weakly supported by bootstrap analysis(<50%). In pairwise comparisons between 6 populations other than that from Sokcho, a very high per generation migration ratio ($N_m$=infinite) and a very low level of geographic distance ($F_{sr}=-0.0123-(-0.0423)$) were observed. The estimates of genetic distance between Sokcho and the other localities were all statistically significant (p<0.05, p<0.01, p<0.001), indicating a limited mtDNA-based gene flow between Sokcho and other regions. The finding of the lowest genetic diversity in the Sokcho population (nucleotide diversity=0.00589) may be a result of relatively small population size and interrupted gene flow to other localities. Consequently, the overall considerable migration of Pacific cod population in Korea caused a genetically homogeneous structure to form, although a distinct population was found in this study.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.6
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• pp.558-566
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• 2003

We fabricated thick film monopole antennas using Li-doped BiNbO$_4$ ceramics and investigated their electrical properties as a function of the Li-doping concentration. Compared with undoped BiNbO$_4$ ceramics, addition of Li$_2$CO$_3$ improved dielectric constant by increasing of ionic polarization, but reduced quality value by increasing of lattice distortion. Antenna properties like gain, bandwidth and radiation patterns were also greatly affected by the addition of Li$_2$CO$_3$. With increasing amount of Li$_2$CO$_3$, the bandwidth of ceramic monopole antenna was increased to 81.7 %, but the gain was reduced to -10.03 dBi. Also radiation patterns were so distorted and showed low dB value by increasing of dielectric loss.