• 한국수산과학회지
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• 제29권3호
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• pp.386-392
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• 1996

A numerical method based on genetic algorithms was introduced to characterize the grain-size distribution more effectively. This technique was proved significant particularly for multimodal size distributions, as was verified for samples from Korea Strait continental shelf. Sediment samples collected from the Korea Strait continental shelf revealed that $96\%$ of the grain-size distributions were multimodal. Therefore, the use of grain-size parameters was not the ideal method. As an alternative method, the decomposition of sue curves into elementary normal component curves was used. Means and standard deviations of 593 decomposed normal components were calculated by a numerical method from 268 size curves of Korea Strait sediments. The mean values of decomposed normal components showed peaks at $1\~3\phi\;and\;7\~9\phi$ size classes. The plot of mean and standard deviation values of the coarse fraction normal components on the map showed a characteristic areal distribution. The characteristic distribution was found to derive from underlying Pleistocene sediment on the basis of sea bottom geologic distribution of the area. The method of decomposition into normal components was found to be more effective than the analysis using traditional grain-size parameters in investigation of multimodal size distribution of Korea Strait shelf sediment.

• Animal Systematics, Evolution and Diversity
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• 제29권3호
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• pp.253-258
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• 2013

Two specimens of Chromis albicauda were collected from Jeju Island, Korea. The species is most similar to C. analis, but is distinguishable by the presence of a white caudal fin when alive, 4-5 scale rows on the anterior portion of the preorbital, and a blackish blotch around anal opening. The results of a molecular analysis based on mitochondrial DNA 16S rRNA sequences confirm that the two individuals are not C. analis but C. albicauda as the genetic distance between the two species is 0.044. A comparison of the two individuals of C. albicauda with yellow chromis shows that none of the previously reported yellow chromis is C. analis, but rather they are C. albicauda. Herein, we suggest the new Korean name "Huin-ggo-ri-no-rang-ja-ri-dom" for C. albicauda.

• 수산해양기술연구
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• 제56권4호
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• pp.316-321
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• 2020

A single juvenile malacanthid specimen (Hoplolatilus chlupatyi) was collected from the South Sea of Korea and identified by DNA barcoding. This species is readily distinguished from other malacanthid species in having well developed rostral spine and elongated spines in the posttemporal and preopercle. A molecular analysis based on mitochondrial DNA COI sequences showed that this species is matched to adult H. chlupatyi (genetic distance = 0.005). Therefore, this is the first record of H. chlupatyi in Korea. We propose new Korean names, "Mu-ji-gae-og-dom-sog" for the genus Hoplolatilus and "Mu-ji-gae-og-dom" for the species H. chlupatyi.

• ALGAE
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• 제33권3호
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• pp.231-241
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• 2018

Genetic continuity of Digenea simplex outside the Atlantic waters remains less studied, despite its long exposure to oriental folk medicine and wide distribution in tropical waters. Mitochondrial COI-5P and plastid rbcL sequences and morphology were investigated for plants from Mexico and additional specimens from Japan. Two new species, Digenea mexicana and Digenea rafaelii, are described for plants that would previously have been recognized as D. simplex in Mexico. D. mexicana grows to 10.5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, simple to branched determinate branchlets with eight pericentral cells, and tetrasporangia on inflated upper parts of determinate branchlets. It occurs intertidally in Quintana Roo, Yucatan Peninsula. D. rafaelii grows to 5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, and simple determinate branchlets with ten pericentral cells. It occurs intertidally in the Gulf of California. Both COI-5P and rbcL sequences revealed the genetic discontinuity between D. mexicana and D. rafaelii.

• 한국수산과학회지
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• 제29권3호
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• pp.320-331
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• 1996

본 연구는 1994년 6월부터 1995년 5월까지 우리 나라 해역에 분포하는 오징어, Todarodes pacificus에 대해 유전자 조성을 관찰하고 군간 비교로 계군을 분석한 것이다. 각기 채집 장소가 다른 9개 지역 집단에 있어서 17개 효소를 사용하여 전기영동법으로 유전적 변이와 분화를 분석하였다. 명확하게 유전자형이 추정된 9개 효소에 대해, 11개의 유전자좌를 표지로 하여, 각기 채집 장소가 다른 9개 지역 집단의 대립유전자빈도와 유전도 변이성의 범위를 조사하였다. 그 결과, 1유전자좌당 평균 대립유전자수는 $1.64\~2.18$개 이었다. 집단의 변이량을 나타내는 다형율 $(P+P^{\ast})$은 $0.273\~0.546$이었다. 평균 이형접합체율 $(H_e)$은 $0.038\~0.085$이었다. 그리고 Nei의 유전적 거리는 $0.00019\~0.000814$로 넓음을 알 수 있었다. 각기 채집 장소가 다른 9개 지역집단간의 유전적 유연관계를 알아 본 결과, 세 집단으로 구분되었다. 이상의 결과를 종합하여 보면, 하계군, 추계군 및 동계군에는 각각의 계군으로 구명되었고, 하계군과 추계군에는 해류나 지리적인 해양환경에 의해 독립된 하나의 지역개체군이 존재하고 있음을 알 수 있었다.

• Mycobiology
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• 제49권3호
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• pp.235-248
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• 2021

This study aimed to understand whether the geo-ecological segregation of native plant species affects the root-associated fungal community. Rhizoplane (RP) and rhizosphere (RS) fungal microbiota of Sedum takesimense native to three geographically segregated coastal regions (volcanic ocean islands) were analyzed using culture-independent methods: 568,507 quality sequences, 1399 operational taxonomic units, five phyla, and 181 genera were obtained. Across all regions, significant differences in the phyla distribution and ratio were confirmed. The Chao's richness value was greater for RS than for RP, and this variance coincided with the number of genera. In contrast, the dominance of specific genera in the RS (Simpson value) was lower than the RP at all sites. The taxonomic identity of most fungal species (95%) closely interacting with the common host plant was different. Meanwhile, a considerable number of RP only residing fungal genera were thought to have close interdependency on their host halophyte. Among these, Metarhizium was the sole genus common to all sites. These suggest that the relationship between potential symbiotic fungi and their host halophyte species evolved with a regional dependency, in the same halophyte species, and of the same natural habitat (volcanic islands); further, the fungal community differenced in distinct geographical regions. Importantly, geographical segregation should be accounted for in national culture collections, based on taxonomical uniqueness.

• Animal Systematics, Evolution and Diversity
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• 제38권2호
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• pp.108-112
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• 2022

An aegid species, Rocinela niponia Richardson, 1909, is a Far Eastern species known from Korean and Japanese waters. In this study, mitochondrial cytochrome c oxidase subunit I (COI) sequences of R. niponia were determined based on four specimens collected from the subtidal zone of Chujado Island, South Korea. We compared DNA barcoding data of this species with its congeners. As a result, there was no intra-specific genetic distance between the four COI sequences of R. niponia. Inter-specific distances between R. niponia and other five aegid species ranged from 23.8% to 35.6%. Morphological diagnosis and images of R. niponia are also provided as a valuable contribution toward the identification of Rocinela species in further taxonomic and ecological studies.

• 한국수산과학회지
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• 제49권2호
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• pp.198-207
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• 2016

Tanaka’s snailfish, Liparis tanakae (Gilbert and Burke, 1912), is distributed throughout the coasts of Korea. To clarify the population structure of L. tanakae, we analyzed the morphological and genetic variation among individuals sampled from three localities surrounding the Korean peninsula: Boryeong in the Yellow Sea, Jinhae in the Korea Strait and Pohang in the East Sea. Principal component analysis based on 20 morphometric characteristics revealed two slightly distinct groups (Boryeong vs. Jinhae and Pohang). However, canonical discriminant analysis clearly revealed three groups, separated according to locality. Pairwise differentiation index (F_ST) comparisons based on 762-base pairs mitochondrial cytochrome b gene sequences showed that Boryeong significantly differed from Jinhae and Pohang, but Jinhae and Pohang did not significantly differ from each other. Our findings suggest that Korean L. tanakae comprise at least two groups. Further studies using more sensitive DNA markers, such as microsatellite DNA, are required.

• Journal of Veterinary Science
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• 제21권6호
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• pp.86.1-86.8
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• 2020

Background: Dicyemids are parasites found in the renal sac of cephalopods. The first species of dicyemid was found from kidneys of the Korean common octopus Callistoctopus minor. Objectives: This study aimed to identify the dicyemid and investigate the effect on renal sac of host. Methods: In this study, we compared the morphological characteristics of isolate to dicyemids (Dicyema sphyrocephalum, Dicyema clavatum, and Dicyema dolichocephalum) reported from C. minor in Japan. We compared the 18S ribosomal RNA (rDNA) and cytochrome c oxidase subunit I (COI) sequences of isolate to the sequences of D. shyrocephalum and D. clavatum. The infected octopuses renal tissues were histologically compared with the tissues of uninfected individuals. Results: The morphological characteristic of this isolated species corresponds to D. sphyrocephalum. The sequences similarities of 18S rDNA and COI gene of isolate are 99.7% and 98.1% with D. sphyrocephalum. We observed morphological changes in the epithelia folds of kidney at the dicyemids attached areas. Conclusions: The present study identified the isolate as D. sphyrocephalum and this is the first report of dicyemid species from Republic of Korea. Further studies on the effects of dicyemids on growth and health status of cephalopods will be needed.

• 한국해양생명과학회지
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• 제6권2호
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• pp.97-105
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• 2021

꼬막은 해양 어업으로써 아시아 전 지역에 있어서 중요한 수산자원 중 하나이다. 하지만, 공장의 산업화, 해양 환경오염, 그리고 지구 온난화로 인해 해양 어업 생산량이 급격히 떨어졌다. 우리나라 남해안의 주요 수산자원인 꼬막의 유전적 특성을 파악하기 위하여 꼬막의 전장유전체를 해독하고 염색체 서열을 규명하였다. 915.4 Mb의 게놈을 조립하였고, 19개의 염색체 유전자 서열을 식별하였다. 꼬막의 유전체에서 25,134개의 유전자들을 확인하였고, 그 중에 22,745개의 유전자들에 대한 기능을 확인했으며, 4,014개의 유전자들에 대한 KEGG pathway를 분석하였다. 꼬막유전체와 8종의 다른 패류와 비교유전체 분석을 통하여 확장/감소(gene gain and loss) 분석을 수행한 결과, 725개의 유전자군의 확장과 479개의 유전자군의 감소를 확인하였다. 꼬막의 homeobox 유전자 클러스터는 촉수담륜동물 내에서 잘 보존된 유전자 구조를 보였다. 또한, 꼬막은 3개의 hemoglobin 유전자들이 피조개의 hemoglobin과 높은 유사성을 보였다. 꼬막의 전장유전체 정보를 통해 꼬막의 환경 적응과 진화의 유전적 특성과 생리적 특성뿐만 아니라, 꼬막 양식의 효율성을 높이는 양식산업에 널리 이용될 수 있는 유전적 정보를 제공할 것이다.