• 식물분류학회지
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• 제46권2호
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• pp.163-174
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• 2016

Gnetum (Gnetaceae, Gnetales) is a gymnosperm genus with ca. 35 species distributed in tropical forests around the world. Due to its dioecious habit and lack of diagnostic characters from vegetative tissue, the identification of Gnetum species is not easy without seeds or reproductive structures. To identify and verify their phylogenetic positions, we applied DNA barcoding to Cambodian Gnetum collections gathered between 2010 and 2015, with previously designed cp matK gene primers. We newly sequenced partial matK sequences from 72 Gnetum collections, 43 out of 72 from Cambodia, and analyzed 115 Gnetum accessions using the neighbor-joining method. The resulting neighbor-joining tree categorized Cambodian Gnetum samples into three clades of species: G. macrostachyum, G. montanum, and G. aff. gracilipes. The recognition of G. aff. gracilipes in Cambodia is reported here for the first time. Taxonomic information for the three recognized Cambodian Gnetum species is provided and the benefits of the taxonomic reevaluation assisted by DNA barcoding are emphasized in this work.

• ALGAE
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• 제35권3호
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• pp.293-301
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• 2020

The applications of DNA barcoding have a wide range of uses, such as in taxonomic studies to help elucidate cryptic species and phylogenetic relationships and analyzing environmental samples for biodiversity monitoring and conservation assessments of species. After obtaining the DNA barcode sequences, sequence similarity-based homology analysis is commonly used. This means that the obtained barcode sequences are compared to the DNA barcode reference databases. This bioinformatic analysis necessarily implies that the overall quantity and quality of the reference databases must be stringently monitored to not have an adverse impact on the accuracy of species identification. With the development of next-generation sequencing techniques, a noticeably large number of DNA barcode sequences have been produced and are stored in online databases, but their degree of validity, accuracy, and reliability have not been extensively investigated. In this study, we investigated the extent to which the amount and types of erroneous barcode sequences were deposited in publicly accessible databases. Over 4.1 million sequences were investigated in three largescale DNA barcode databases (NCBI GenBank, Barcode of Life Data System [BOLD], and Protist Ribosomal Reference database [PR2]) for four major DNA barcodes (cytochrome c oxidase subunit 1 [COI], internal transcribed spacer [ITS], ribulose bisphosphate carboxylase large chain [rbcL], and 18S ribosomal RNA [18S rRNA]); approximately 2% of erroneous barcode sequences were found and their taxonomic distributions were uneven. Consequently, our present findings provide compelling evidence of data quality problems along with insufficient and unreliable annotation of taxonomic data in DNA barcode databases. Therefore, we suggest that if ambiguous taxa are presented during barcoding analysis, further validation with other DNA barcode loci or morphological characters should be mandated.

• Animal Systematics, Evolution and Diversity
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• 제36권1호
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• pp.10-14
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• 2020

Pagurus is the most diverse hermit crab genus in Korea. In this study, the cytochrome c oxidase subunit I (COI) and 16S rRNA of 24 individuals from four Korean Pagurus species (i.e., 7 Pagurus brachiomastus, 8 P. proximus, 8 P. simulans, and 1 P. rectidactylus) were sequenced and analyzed. No genetic difference was found between the COI and 16S rRNA sequences of P. brachiomastus and P. simulans, and the COI sequences of P. rectidactylus and P. quinquelineatus (comparative species from NCBI). Considering the morphological and ecological characteristics together, we assume that P. simulans and P. rectidactylus are subspecies of P. brachiomastus and P. quinquelineatus, respectively. This study should facilitate further research on the taxonomic status of these species.

• Animal Systematics, Evolution and Diversity
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• 제36권3호
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• pp.258-263
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• 2020

The aim of this study is to report monotypic species, Nonparahalosydna pleiolepis(Marenzeller, 1879) for the first time from Korean waters with its DNA barcoding data. We collected individuals of the species from the subtidal zone of southern coast of Korea through scuba diving. To estimate DNA barcoding gap, the pairwise genetic distances were calculated between N. pleiolepis and its congeners (Halosydna brevisetosa Kinberg, 1856 and Lepidonotus squamatus (Linnaeus, 1758)) based on the cytochrome c oxidase subunit I gene (COI). Inter-specific genetic distances ranged from 18.7% to 24.6%, while intra-specific genetic distance within N. pleiolepis ranged from 0.3% to 0.5%. The maximum intra-specific genetic distance among the three species was 1.4%. The morphological diagnosis of N. pleiolepis with a taxonomic note on the species were also provided.

• Animal Systematics, Evolution and Diversity
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• 제28권4호
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• pp.269-278
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• 2012

Gobiids are hyperdiverse compared with other teleost groups, with about 2,000 species occurring in marine, freshwater, and blackish habitats, and they show a remarkable variety of morphologies and ecology. Testing the effectiveness of DNA barcodes on species that have emerged as a result of radiation remains a major challenge in evolutionary biology. Here, we used the cytochrome c oxidase subunit 1 (COI) sequences from 144 species of gobies and related species to evaluate the performance of distance-based DNA barcoding and to conduct a phylogenetic analysis. The average intra-genus genetic distance was considerably higher than that obtained in previous studies. Additionally, the interspecific divergence at higher taxonomic levels was not significantly different from that at the intragenus level, suggesting that congeneric gobies possess substantial interspecific sequence divergence in their COI gene. However, levels of intragenus divergence varied greatly among genera, and we do not provide sufficient evidence for using COI for cryptic species delimitation. Significantly more nucleotide changes were observed at the third codon position than that at the first and the second codons, revealing that extensive variation in COI reflects synonymous changes and little protein level variation. Despite clear signatures in several genera, the COI sequences did resolve genealogical relationships in the phylogenetic analysis well. Our results support the validity of COI barcoding for gobiid species identification, but the utilization of more gene regions will assist to offer a more robust gobiid species phylogeny.

• Genomics & Informatics
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• 제10권3호
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• pp.206-211
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• 2012

DNA barcoding has been widely used in species identification and biodiversity research. A short fragment of the mitochondrial cytochrome c oxidase subunit I (COI) sequence serves as a DNA bio-barcode. We collected DNA barcodes, based on COI sequences from 156 species (529 sequences) of fish, insects, and shellfish. We present results on phylogenetic relationships to assess biodiversity the in the Korean peninsula. Average GC% contents of the 68 fish species (46.9%), the 59 shellfish species (38.0%), and the 29 insect species (33.2%) are reported. Using the Kimura 2 parameter in all possible pairwise comparisons, the average interspecific distances were compared with the average intraspecific distances in fish (3.22 vs. 0.41), insects (2.06 vs. 0.25), and shellfish (3.58 vs. 0.14). Our results confirm that distance-based DNA barcoding provides sufficient information to identify and delineate fish, insect, and shellfish species by means of all possible pairwise comparisons. These results also confirm that the development of an effective molecular barcode identification system is possible. All DNA barcode sequences collected from our study will be useful for the interpretation of species-level identification and community-level patterns in fish, insects, and shellfish in Korea, although at the species level, the rate of correct identification in a diversified environment might be low.

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.40-47
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• 2015

The genus Acteniceromorphus is taxonomically reviewed for the first time in Korea. From the previously recorded three species, two species, A. selectus (Candèze, 1894) and A. fulvipennis (Lewis, 1894) are confirmed as misidientification of species which are endemic to Japan. Another species, A. chlamydatus (Lewis, 1894) is unavailable any Korean specimens. Additionally, we found A. ferrugineipennis (Candèze, 1879) as new to Korea. We also provide a comparison of DNA barcoding for two species previously misidentified and the newly recorded species, except A. chlamydatus. DNA barcoding result shows that each species is clearly delimited at species-level from each other by large interspecific genetic distance over 7.2%.

• 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.

• 식물분류학회지
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• 제43권1호
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• pp.46-55
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• 2013

울릉도에만 한정 분포하는 회솔나무(Taxus cuspidata var. latifolia)의 분류학적 위치를 파악하기 위해 근연종인 주목(T. cuspidata var. cuspidata), 설악눈주목(T. caespitosa), 일본에 분포하는 T. cuspidata var. nana 4분류군을 대상으로 외부형태학적 연구와 DNA 바코딩 연구를 수행하였다. 회솔나무는 여러 학자들에 의해 주목의 이명으로 처리되거나 주목의 변종으로 처리되었던 분류군으로 분류학적 위치에 대한 이견이 많은 분류군이다. 이번 연구를 통해 회솔나무는 외부형태학적으로 근연종에 비해 원줄기는 곧고, 잎의 길이와 폭은 1.4배 이상 길고 종자는 가종피 바깥으로 돌출되는 특징으로 뚜렷이 구별되었다. DNA 바코딩 연구를 통해 matK, rbcL, trnL-trnF(trnL intron 포함) 구간의 염기서열을 비교한 결과 회솔나무는 유럽주목인 Taxus baccata와는 별개의 분계조를 형성하고 주목과 하나의 분계조를 형성하며 100% 동일한 염기서열을 갖는 것으로 나타났다. 한국 특산종인 설악눈주목은 외부형태학적으로 원줄기가 여러 개 나오며 옆으로 기고 잎의 길이와 폭은 주목에 비해 0.8-0.9배 작은 특징으로 뚜렷이 구별되지만, DNA 바코딩 연구 결과 주목과 100% 동일한 염기서열 서열을 가지며 하나의 분계조를 형성했다. 따라서 본 연구결과를 바탕으로 울릉도에 한정 분포하며 근연종에 비해 뚜렷한 형태학적 차이를 보이는 회솔나무는 T. cuspidata의 변종인 T. cuspidata var. latifolia로 인정하는 것이 타당한 것으로 판단된다.

• Animal Systematics, Evolution and Diversity
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• 제37권3호
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• pp.235-241
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• 2021

To provide better taxonomic information of the genus Nectoneanthes, the two DNA barcode regions of mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal DNA (rDNA) sequences of Nectoneanthes oxypoda and N. uchiwa were determined. In addition, the respective sequences of four nereidid species closely related to Nectoneanthes were retrieved from GenBank for comparison and to estimate intra- and inter-specific genetic distances. The aligned sequence lengths of COI and 16S rDNA were 570 bp and 419 bp long, respectively. The mean intraspecific variation in both markers was less than 1% in all species except for that in COI of H. diadroma (1.87%). The mean interspecific variation between N. oxypoda and N. uchiwa was 12.02% regarding COI and 1.85% regarding 16S rDNA. In contrast, the mean interspecific variation between species of other genera was comparably higher(i.e., genus Perinereis: 20.5% in COI and 8.3% in 16S rDNA; genus Hediste: 13.18% in COI and 2.64% in 16S rDNA), compared with that between the two Nectoneanthes species. This result indicated that these Nectoneanthes species are genetically more closely related than other congeneric species of different genera. The DNA barcoding information on Nectoneanthes species generated in this study provides valuable insights for further biodiversity studies on nereidid species.