• Fisheries and Aquatic Sciences
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• 제12권1호
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• pp.44-48
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• 2009

Nucleotide sequences of about 500 bp from the 5' end of mitochondrial (mt) DNA Cytochrome Oxidase I (COI) were analyzed to estimate the genetic variation between wild and cultured populations of the ascidian Halocynthia roretzi from two sites along the coast of Korea. A total of 25 haplotypes were defined by 21 variable nucleotide sites in the examined COI region. Genetic diversity (haplotype diversity and nucleotide divergence) of wild populations was higher than that of the cultured population. These data suggest that reduced genetic variation in the cultured population may have results from bottleneck effect caused by the use of a limited number of parental stock and pooling of gametes for fertilization. Pairwise population $F_{ST}$ estimates inferred that wild and cultured populations were genetically distinct. The combined results suggest that sequence polymorphism in the COI region would be preferable for estimating the genetic diversity of ascidian populations.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.49-56
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• 2012

Genetic variation in the Asian shore crab Hemigrapsus sanguineus was determined from partial mitochondrial DNA (mtDNA) sequences of the cytochrome b (Cytb) gene. Samples included 143 crabs from six localities along three coastlines in South Korea. A nucleotide sequence analysis revealed 38 variable sites in a 470-bp sequence, which defined 37 haplotypes. The haplotypes were not associated geographically and had a shallow genealogy. Pairwise $F_{ST}$ tests and a two-dimensional scaling analysis revealed no significant genetic differentiation among most of the populations. The low pairwise comparison values, but significant genetic differentiation of a northeastern population from all other populations, might have been influenced by a restriction in gene flow caused by hydrographic conditions such as ocean boundaries. The high haplotype diversity, low nucleotide diversity, and time since H. sanguineus expansion in Korean coastal waters indicate rapid population growth and a recent, sudden expansion in the Late Pleistocene.

• Animal cells and systems
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• 제14권3호
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• pp.197-206
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• 2010

The population structure of brown sole was examined in a total of 308 samples collected from three geographical groups: one locality (Gangneung) on the east side of the Korean Peninsula, two localities (Erimo and Tomakomai) on the southeastern side and four localities (Onishika, Teshio, Tomamae and Yoichi) on the northwestern side of Hokkaido Island, Japan, by using sequences of 484 bp from the 5' end of the control region of mtDNA. We detected 225 haplotypes, but 183 of them were unique to an individual. A total of 116 nucleotide sites were variable. Haplotype diversity (h) was very high, ranging from 0.989 to 1.000, and nucleotide diversity (${\pi}$) was detected between 0.015 and 0.022. Genetic distances (${\Phi}_{ST}$) within populations, among populations and among geographical groups were low (0.0002 to 0.0014). No significant difference was detected by the AMOVA test (P < 0.05). Pairwise $F_{ST}$ values between sampling localities were also low and not significant. Genetic differentiation was not detected among sampling localities.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.137-144
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• 2004

The diamondback moth, Plutella xylostella, is notorious because of its extensive potential and actual dispersal ability. Previously, the Korean populations of P. xylostella was extensively collected and analyzed for their genetic population structure using a portion of mitochondrial DNA (mtDNA). One of the postulated characteristics on population genetic structure of the species includes the presence of heterogeneous haplotypes, possibly possessed by some dispersed ones from neighboring countries. In this study, we sequenced ten P. xylostella collected from China (∼2,000 km away from the middle part of Korea) to know the genetic relationships of these to the Korean P. xylostella. Sequence analysis of the identical portion of COI gene resulted in five haplotypes with the sequence divergence ranging from 0.5% (two nucleotides) to 1.1 % (five nucleotides) among them and from 0.7% (three) to 2.5% (11) to the pre-existing 52 Korean haplotypes. Phylogenetic analysis showed that the Chinese P. xylostella were neither clearly separated from the Korean haplotypes nor clustered with one heterogeneous Korean haplotype. This result reinforces the significance of gene flow in this species and suggests to exclude the possibility that the heterogeneous Korean haplotypes may have emigrated from China, where our samples were obtained, although further extensive investigation is required.

• Korean Journal of Poultry Science
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• 제39권4호
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• pp.311-315
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• 2012

The increasing demand for Korean native chicken meat indicates that the discovery of haplotypes is very important from both economic and conservation points of view. In this study, mtDNA D-loop sequences from two crossbred Korean native chicken populations of 138 individuals were investigated. Twenty six nucleotide substitutions were identified from sequence analysis and were classified into 12 haplotypes. The haplotype H_8 represents 73.47% of Woorimatdag (chicken population) sequences, which were identified in all five Woorimatdag chicken populations investigated. The H_7 haplotype (Dhap1) for D population covers 45% sequences, which indicate maternal inheritance from black Korean native chicken. On the other hand, Chap3 and Chap4 for C population are specific haplotypes, as H_5 and H_2, respectively. Based on the network profiles, six SNPs (C199T, A239G, G242A, A291G, T330C and C391A) of the D-loop region are effective markers for discrimination between Woorimatdag and Hanhyup chicken populations. Also, the phylogenetic analyses of Woorimatdag and Hanhyup chicken populations were used to identify the genetic relationships among the haplotypes. The results presented here can be used for developing molecular markers to discriminate between two commercial Korean native chickens.

• Korean Journal of Ichthyology
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• 제32권2호
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• pp.39-48
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• 2020

The slender shinner (Pseudopungtungia tenuicorpa), a tiny freshwater fish of about 8 to 10 cm belonging to Cyprinidae, is an endangered species found only in the Han and Imjin Rivers on the Korean Peninsula. During the breeding season, this species spawns in nests of Coreoperca herzi, a predator of this species, or small crevices on rocks. This unique reproductive ecology can make this species more vulnerable to anthropogenic perturbance that can further limit the places to spawn. Here, mtDNA and microsatellite loci were analyzed to identify the genetic diversity and structure of slender shinners and further to provide the basic data necessary for the conservation planning of this species. A total of 28 polymorphic microsatellite markers were developed using Illumina paired-end sequencing, and 67 slender shinners collected from three localities in the Han River were genotyped using these loci. This species showed a remarkably high level of genetic diversity with mean expected heterozygosity of 0.914 and mean allele number per locus of 27.9, and no signature of drastic demographic decline was detected. As a result of our microsatellite analysis, the genetic structure between the two stems of the Han River, North Han and South Han, was prominent. Such a genetic structure was also evident in the sequence analysis of 14 haplotypes obtained from mtDNA control region. Although slender shinners are only found in very limited areas around the world, the genetic structure indicates that there is a block of gene flow among the populations, which should be reviewed in the future if management and restoration of this species is needed.

• Asian-Australasian Journal of Animal Sciences
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• 제28권8호
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• pp.1066-1074
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• 2015

In contrast to high genetic diversity of mitochondrial DNA (mtDNA), equine Y chromosome shows extremely low variability, implying limited patrilines in the domesticated horse. In this study, we applied direct sequencing and restriction fragment length polymorphism (RFLP) methods to investigate the polymorphisms of 33 Y chromosome specific loci in 304 Chinese indigenous horses from 13 breeds. Consequently, two Y-single nucleotide polymorphisms (SNPs) (Y-45701/997 and Y-50869) and one Y-indel (Y-45288) were identified. Of those, the Y-50869 (T>A) revealed the highest variation frequency (24.67%), whereas it was only 3.29% and 1.97% in Y-45288 (T/-) and Y-45701/997 (G>T) locus, respectively. These three mutations accounted for 27.96% of the total samples and identified five Y-SNP haplotypes, demonstrating genetic diversity of Y chromosome in Chinese horses. In addition, all the five YSNP haplotypes were shared by different breeds. Among 13 horse breeds analyzed, Balikun horse displayed the highest nucleotide diversity (${\pi}=5.6{\times}10^{-4}$) and haplotype diversity (h = 0.527), while Ningqiang horse showed the lowest nucleotide diversity (${\pi}=0.00000$) and haplotype diversity (h = 0.000). The results also revealed that Chinese horses had a different polymorphic pattern of Y chromosome from European and American horses. In conclusion, Chinese horses revealed genetic diversity of Y chromosome, however more efforts should be made to better understand the domestication and paternal origin of Chinese indigenous horses.

• Korean Journal of Plant Taxonomy
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• 제45권3호
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• pp.254-261
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• 2015

Genetic variations of Abies koreana and Abies nephrolepis were assessed using two mitochondrial DNA regions (nad5 intron 4 and nad5 intron 1) for 16 natural populations to understand their phylogeographical history. Seven polymorphic sites of the two combined regions resulted in the resolution of four haplotypes (M1-M4). The average gene diversity within the population ($H_S$) was 0.098, the total gene diversity ($H_T$) was 0.620, and the interpopulation differentiation was $G_{ST}=0.841$, $N_{ST}=0.849$. The populations were divided into three groups (northern area, central area, southern area) according to their geographic locations. The populations of the northern and southern areas were mostly fixed for M1 and M2, respectively. The populations of the central area showed the highest levels of gene diversity ($H_T=0.654$) due to introgression from the northern area and southern area. The presence of a single mtDNA haplotype in the southern area suggests that current widespread populations have expanded to the central area from a specific refugium population after the last glacial period.

• The Plant Pathology Journal
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• 제38권5호
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• pp.541-549
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• 2022

Potato late blight caused by Phytophthora infestans is a destructive disease in Korea. To elucidate the genomic variation of the mitochondrial (mt) genome, we assembled its complete mt genome and compared its sequence among different haplotypes. The mt genome sequences of four Korean P. infestans isolates were revealed by Illumina HiSeq. The size of the circular mt genome of the four major genotypes, KR_1_A1, KR_2_A2, SIB-1, and US-11, was 39,872, 39,836, 39,872, and 39,840 bp, respectively. All genotypes contained the same 61 genes in the same order, comprising two RNA-encoding genes, 16 ribosomal genes, 25 transfer RNA, 17 genes encoding electron transport and ATP synthesis, 11 open reading frames of unknown function, and one protein import-related gene, tatC. The coding region comprised 91% of the genome, and GC content was 22.3%. The haplotypes were further analyzed based on sequence polymorphism at two hypervariable regions (HVRi), carrying a 2 kb insertion/deletion sequence, and HVRii, carrying 36 bp variable number tandem repeats (VNTRs). All four genotypes carried the 2 kb insertion/deletion sequence in HVRi, whereas HVRii had two VNTRs in KR_1_A1 and SIB-1 but three VNTRs in US-11 and KR_2_A2. Minimal spanning network and phylogenetic analysis based on 5,814 bp of mtDNA sequences from five loci, KR_1_A1 and SIB-1 were classified as IIa-6 haplotype, and isolates KR_1_A2 and US-11 as haplotypes IIa-5 and IIb-2, respectively. mtDNA sequences of KR_1_A1 and SIB-1 shared 100% sequence identity, and both were 99.9% similar to those of KR_2_A2 and US-11.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.170-176
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• 2012

Genetic diversities, population genetic structures and demographic histories of the thread-sail filefish Stephanolepis cirrhifer were investigated by nucleotide sequencing of 336 base pairs of the mitochondrial DNA (mtDNA) control region in 111 individuals collected from six populations in Korean coastal waters. A total of 70 haplotypes were defined by 58 variable nucleotide sites. The neighbor-joining tree of the 70 haplotypes was shallow and did not provide evidence of geographical associations. Expansion of S. cirrhifer populations began approximate 51,000 to 102,000 years before present, correlating with the period of sea level rise since the late Pleistocene glacial maximum. High levels of haplotype diversities ($0.974{\pm}0.029$ to $1.000{\pm}0.076$) and nucleotide diversities (0.014 to 0.019), and low levels of genetic differentiation among populations inferred from pairwise population FST values (-0.007 to 0.107), support an expansion of the S. cirrhifer population. Hierarchical analysis of molecular variance (AMOVA) revealed weak but significant genetic structures among three groups ($F_{CT}$ = 0.028, p<0.05), and no genetic variation within groups (0.53%; $F_{SC}$ = 0.005, p = 0.23). These results may help establish appropriate fishery management strategies for stocks of S. cirrhifer and related species.