• Korean Journal of Plant Resources
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• v.25 no.5
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• pp.517-522
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• 2012

This study was conducted to investigate the morphological and anatomical characteristics of needle and the genetic diversity of Pinus pumila Regel which is a unique and the southern peripheral population in South Korea. ANOVA test showed that there were significant differences among individuals within population in all 8 needle characteristics. Average characteristics of 66 individuals were 53.59 mm in needle length, 0.78 mm in needle width, 68.98 in needle index, 0.65 mm in needle thickness, 4.56 ea. in maximum stomata row, 3.80 ea. in minimum stomata row, 8.36 ea. in total stomata row and 1.71 ea. in resin canals, respectively. Resin canal per needle of this species ranged from one to three, depending on external type. Especially, arrangement types were 69.47% in two resin canals and 30.45% in a single resin canal. A total of 78 bands was generated from 9 selected I-SSR primers. The estimates of genetic variation were 61.5% in proportion of polymorphic bands (P), 1.698 in effective number of alleles ($A_e$), 0.388 in expected heterozygosity ($H_e$) and 0.567 in Shannon's information index (S.I.), respectively.

• Korean Journal of Plant Taxonomy
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• v.46 no.4
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• pp.361-370
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• 2016

An area comprising Juwangsan National Park and its adjacent mountains (southeastern Korean Peninsula) is a good model system for testing the effects of physical barriers to gene flows in plant populations. We predicted that plant species consisting of isolated populations are genetically more differentiated than those that are rather continuously distributed. Most populations of Sedum polytrichoides occur in four isolated valleys, and we assessed the genetic variability and structures using twelve allozyme loci in ten populations. We also compared the present results to earlier findings pertaining to the two co-occurring herbs Hylotelephium ussuriense (${\equiv}$ Sedum ussuriense) (growing only in the four isolated valleys) and S. kamtschaticum (rather continuously distributed). We found moderate levels of within-population genetic variation in S. polytrichoides ($H_{e}=0.112$). Estimates of among-population divergence in S. polytrichoides were also moderate ($F_{ST}=0.250$) and, as expected, very similar to that of H. ussuriense (0.261) but considerably higher than the variation in S. kamtschaticum (0.165). An analysis of molecular variance (AMOVA) revealed that S. polytrichoides and H. ussuriense had higher percentages of among-valley variation (19% each) than S. kamtschaticum (4%). Most of this variation, as also indicated by the STRUCTURE program, was due to differences in genetic profiles between the two central valleys. We concluded that the genetic differences observed between species (S. kamtschaticum vs. S. polytrichoides and H. ussuriense) are mainly due to differences in their distribution within the study area.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.87-95
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• 2024

The giant jellyfish, Nemopilema nomurai, is an endemic species found in Northeast Asian waters and their population structures, such as size and genetics, and their environmental characteristics were investigated. N. nomurai was obtained from the Yellow and Northern East China Seas during the summers of 2006, 2007, and 2009. In the northern Yellow Sea, small-sized jellyfish were found to be dominant and towards the southern seas, the size of the jellyfish increased. In the northern East China Sea, only one mode of jellyfish was found in May, and the number of modes increased up-to five in July. However, at the center of the Yellow Sea, one or two modes were found in July, 2007. Thus, different jellyfish populations were present in the northern East China Sea and the Yellow Sea. However, based on first appearance and a cohort analysis using the bell diameter, the jellyfish population in the northern Yellow Sea might be recognized as a distinct group that differed from those found in the northern East China Sea. Furthermore, mitochondrial DNA sequences (cytochrome c oxidase subunit I) of N. nomurai were, determined and compared with genetic structures obtained from jellyfish in the Yellow Sea. The genetic diversity of N. nomurai was highest in the regions around the northern East China Sea and at the center of the Yellow Sea and was the lowest around the northern Yellow Sea. Thus, N. nomurai populations in the Yellow Sea and northern East China Sea might be different concerning their seeding places.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.56-62
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• 2002

The International Union for Conservation of Nature and Natural Resources (IUCN) considers the western/lowland bongo Tragelaphus eurycerus eurycerus to be a threatened species, and the eastern/mountain bongo Tragelaphus eurycerus isaaci an endangered species［1］. Although extinction is considered by many biologists to be a natural process during evolution, the exponential growth of the human population has drastically and prematurely reduced the numbers and genetic diversity of many species［2］. Species have evolved to adapt to a specific habitat or environment that meet their survival needs. Alteration or destruction of their habitat results in a species becoming incapable of adapting and hence becoming threatened with extinction. A widespread scientific and public consensus has emerged suggesting that governments should assign high priority to the maintenance of biological diversity via habitat preservation and management far species conservation［3］. Unfortunately, the loss of biological diversity far surpasses the available conservation resources and species are lost forever on a daily basis［4］. Notwithstanding the focus on habitat preservation and wildlife management, conservation biologists have also become increasingly interested in using the technologies of reproductive and developmental biology to help manage or rescue endangered species［5］.

• Animal Bioscience
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• v.36 no.7
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• pp.991-1002
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• 2023

Objective: This study aimed to elucidate the underlying gene regions responsible for productive, phenotypic or adaptive traits in different ecological types of Tibetan sheep and the discovery of important genes encoding valuable traits. Methods: We used whole-genome resequencing to explore the genetic relationships, phylogenetic tree, and population genetic structure analysis. In addition, we identified 28 representative Tibetan sheep single-nucleotide polymorphisms (SNPs) and genomic selective sweep regions with different traits in Tibetan sheep by fixation index (Fst) and the nucleotide diversity (θπ) ratio. Results: The genetic relationships analysis showed that each breed partitioned into its own clades and had close genetic relationships. We also identified many potential breed-specific selective sweep regions, including genes associated with hypoxic adaptability (MTOR, TRHDE, PDK1, PTPN9, TMTC2, SOX9, EPAS1, PDGFD, SOCS3, TGFBR3), coat color (MITF, MC1R, ERCC2, TCF25, ITCH, TYR, RALY, KIT), wool traits (COL4A2, ERC2, NOTCH2, ROCK1, FGF5, SOX9), and horn phenotypes (RXFP2). In particular, a horn-related gene, RXFP2, showed the four most significantly associated SNP loci (g. 29481646 A>G, g. 29469024 T>C, g. 29462010 C>T, g. 29461968 C>T) and haplotypes. Conclusion: This finding demonstrates the potential for genetic markers in future molecular breeding programs to improve selection for horn phenotypes. The results will facilitate the understanding of the genetic basis of production and adaptive unique traits in Chinese indigenous Tibetan sheep taxa and offer a reference for the molecular breeding of Tibetan sheep.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.2
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• pp.94-101
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• 2007

Analysis of population structure of Oncorhynchus keta, the most abundant salmon in the East Sea of Korea, has not been much carried out despite its importance as a fishery resource in the North Pacific. Currently, molecular methods are being applied to stock identification and a method of using single nucleotide polymorphisms (SNPs) is getting more popular. In this study, we analyzed the 720 bp long sequence of the mtDNA COIII-ND3-ND4L region in order to examine genetic similarity-dissimilarity among the Korea chum salmons of each stream and their relationship with the Japan chum salmons. A total of 152 individuals were analyzed, 108 from 3 locations of Korea and 44 from 2 locations of japan, which resulted in as many as 29 different haplotypes. Pairwise $F_{ST}$ and AMOVA tests of the populations show that there is no significant population-level genetic difference among the chum salmons analyzed ($F_{ST}<0.07$). On the other hand, haplotype relationships among the individuals reveal that approximately 25% of the Korea salmons consist genetic lineages independent of Japan salmons and also that a genetic lineage exists in the Puk river and the Namdae river salmons independent of the Wangpi river salmons of Korea.

• Journal of Ginseng Research
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• v.35 no.4
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• pp.399-412
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• 2011

Little is known about the genetics or genomics of Panax ginseng. In this study, we developed 70 expressed sequence tagderived polymorphic simple sequence repeat markers by trials of 140 primer pairs. All of the 70 markers showed reproducible polymorphism among four Panax species and 19 of them were polymorphic in six P. ginseng cultivars. These markers segregated 1:2:1 manner of Mendelian inheritance in an $F_2$ population of a cross between two P. ginseng cultivars, 'Yunpoong' and 'Chunpoong', indicating that these are reproducible and inheritable mappable markers. A phylogenetic analysis using the genotype data showed three distinctive groups: a P. ginseng-P. japonicus clade, P. notoginseng and P. quinquefolius, with similarity coefficients of 0.70. P. japonicus was intermingled with P. ginseng cultivars, indicating that both species have similar genetic backgrounds. P. ginseng cultivars were subdivided into three minor groups: an independent cultivar 'Chunpoong', a subgroup with three accessions including two cultivars, 'Gumpoong' and 'Yunpoong' and one landrace 'Hwangsook' and another subgroup with two accessions including one cultivar, 'Gopoong' and one landrace 'Jakyung'. Each primer pair produced 1 to 4 bands, indicating that the ginseng genome has a highly replicated paleopolyploid genome structure.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.129-134
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• 2015

Schistosoma haematobium is one of the most prevalent parasitic flatworms, infecting over 112 million people in Africa. However, little is known about the genetic diversity of natural S. haematobium populations from the human host because of the inaccessible location of adult worms in the host. We used 4 microsatellite loci to genotype individually pooled S. haematobium eggs directly from each patient sampled at 4 endemic locations in Africa. We found that the average allele number of individuals from Mali was significantly higher than that from Nigeria. In addition, no significant difference in allelic composition was detected among the populations within Nigeria; however, the allelic composition was significantly different between Mali and Nigeria populations. This study demonstrated a high level of genetic variability of S. haematobium in the populations from Mali and Nigeria, the 2 major African endemic countries, suggesting that geographical population differentiation may occur in the regions.

• The Plant Pathology Journal
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• v.30 no.2
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• pp.195-199
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• 2014

Apple stem pitting virus (ASPV), of the Foveavirus genus in the family Betaflexiviridae, is one of the most common viruses of apple and pear trees. To examine variability of the coat protein (CP) gene from ASPV, eight isolates originating from 251 apple trees, which were collected from 22 apple orchards located in intensive apple growing areas of the North Gyeongsang and North Jeolla Provinces in Korea, were sequenced and compared. The nucleotide sequence identity of the CP gene of eight ASPV isolates ranged from 77.0 to 97.0%, while the amino acid sequence identity ranged from 87.7 to 98.5%. The N-terminal region of the viral CP gene was highly variable, whereas the C-terminal region was conserved. Genetic algorithm recombination detection (GARD) and single breakpoint recombination (SBP) analyses identified base substitutions between eight ASPV isolates at positions 54 and 57 and position 771, respectively. GABranch analysis was used to determine whether the eight isolates evolved due to positive selection. All values in the GABranch analysis showed a ratio of substitution rates at non-synonymous and synonymous sites (dNS/dS) below 1, suggestive of strong negative selection forces during ASPV CP history. Although negative selection dominated CP evolution in the eight ASPV isolates, SLAC and FEL tests identified four possible positive selection sites at codons 10, 22, 102, and 158. This is the first study of the ASPV genome in Korea.

• Journal of KIISE:Software and Applications
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• v.31 no.5
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• pp.570-576
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• 2004

It is very difficult to efficiently solve a large-scaled maximal covering problem(MCP) by a genetic algorithm. In this paper, we present new crossover and mutation operators specially designed for genetic algorithms to solve large-scaled MCPs efficiently. We also introduce a novel genetic algorithm employing unexpressed genes. Unexpressed genes are the genes which are not expressed and thus do not affect the evaluation of the individuals. These genes play the role of reserving information susceptible to be lost by the application of genetic operations but is suspected to be potentially useful in later generations. The genetic algorithm employing unexpressed genes enjoys the advantage of being able to maintain diversity of the population and thus can search more efficiently to solve large-scaled MCPs. Experiments with large-scaled real MCP data has shown that our genetic algorithm employing unexpressed genes significantly outperforms tabu search which is one of the popularly used local neighborhood search algorithms for optimization.