• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.295-299
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• 2019

We developed and validated species-specific primers for Branchiostegus japonicus and Branchiostegus albus to prevent the sale of B. albus as B. japonicus. Primers for B. japonicus and B. albus were designed against the cytochrome b gene. Multiplex PCR showed a 288 bp amplicon for B. japonicus, a 159 bp amplicon for B. albus, and a 502 bp amplicon for the internal control. The PCR product bands for B. japonicus, B. albus, and the internal control were present at 1 ng each. The specificity and sensitivity of the primers developed in this study were validated by testing 38 B. japonicus strains and 13 B. albus strains. Using this monitoring method, fake fish did not appear due to the agreement between the experimental results and the species. Therefore, the developed multiplex PCR method was suitable for differentiating B. japonicus and B. albus.

• Animal cells and systems
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• v.13 no.3
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• pp.323-329
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• 2009

We analyzed partial sequences of cytochrome b (cyt-b), a mitochondrial DNA (mtDNA) gene, to determine the genetic relationships between six horsehead fish species: Branchiostegus japonicus, Branchiostegus albus, Branchiostegus auratus, Branchiostegus argentatus, Branchiostegus wardi, and an unidentified Branchiostegus species. The specimens were collected in Korea, China, Japan, and Vietnam. We compared their molecular phylogenetic relationships inferred from mtDNA cyt-b sequences with an osteological analysis. The unidentified species, B. sp., was similar to B. albus in terms of the lack of triangular silver-white dot at the posterior region of eyes (vs. large one present in B. japonicus), but was also similar to B. japonicus in terms of the presence of a straight-shaped first hemal spine (vs. a curve-shaped hemal spine in B. albus). Analysis of the mtDNA cyt-b sequences indicated that the smallest estimated sequence divergence was between the B. japonicus and B. sp. (0.70-0.94%), whereas the largest difference was between B. auratus and B. argentatus (23.06-23.36%). Both the maximum parsimony and maximum likelihood trees showed that the B. sp. was closely clustered with B. japonicus, and that B. auratus was most distant from the other species. When comparing the osteological characters, UPGMA tree showed that the B. japonicus and B. sp. were the most closely clustered species, and B. auratus was the most distantly clustered fish relative to the other species. The shape of the nasal, otolith and first hemal spine was informative for distinguishing B. auratus from the other species. These osteological differences were consistent with the differences in mtDNA.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.40-48
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• 1998

Comparative morphology of the genus Branchiostegus has been investigated based on the specimens collected from the adjacent waters of Korea. Branchiostegus japonicus has a distinctive silvery white triangular marking behind eye, while B. albus has nothing. B. albus has about 4 yellow strips along the posterior margin, however, remainder have 5 to 6 longitudinal yellow stripes. In B. auratus, its head length is more than 26% of standard length, but, less than 26% in B. argentatus. This study reveals that B. argentatus is the first record from Korea, and we propose "T$\check{u}$ng-h$\acute{u}$k-ch$\check{o}$m-ok-tu-$\check{o}$" for B. argentatus as a new Korean name.

• Journal of Life Science
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• v.27 no.11
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• pp.1331-1339
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• 2017

DNA barcoding is the identification of a species based on the DNA sequence of a fragment of the cytochrome C oxidase subunit I (COI) gene in the mitochondrial genome. It is widely applied to assist with the sustainable development of fishery-product resources and the protection of fish biodiversity. This study attempted to verify horse-head fish (Branchiostegus japonicus) and fake horse-head fish (Branchiostegus albus) species, which are commonly consumed in Korea. For the validation of the two species, a real-time PCR method was developed based on the species' mitochondrial DNA genome. Inter-species variations in mitochondrial DNA were observed in a bioinformatics analysis of the mitochondrial genomic DNA sequences of the two species. Some highly conserved regions and a few other regions were identified in the mitochondrial COI of the species. In order to test whether variations in the sequences were definitive, primers that targeted the varied regions of COI were designed and applied to amplify the DNA using the real-time PCR system. Threshold-cycle (Ct) range results confirmed that the Ct ranges of the real-time PCR were identical to the expected species of origin. Efficiency, specificity and cross-reactivity assays showed statistically significant differences between the average Ct of B. japonicus DNA ($21.85{\pm}3.599$) and the average Ct of B. albus DNA ($33.49{\pm}1.183$) for confirming B. japonicus. The assays also showed statistically significant differences between the average Ct of B. albus DNA ($22.49{\pm}0.908$) and the average Ct of B. japonicus DNA ($33.93{\pm}0.479$) for confirming B. albus. The methodology was validated by using ten commercial samples. The genomic DNA-based molecular technique that used the real-time PCR was a reliable method for the taxonomic classification of animal tissues.

• Journal of Food Hygiene and Safety
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• v.36 no.4
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• pp.331-341
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• 2021

DNA barcode sequences of commercial seafood products, which are difficult to morphologically discriminate, were analyzed to determine cases of food fraud. The gene sequences were analyzed by amplifying the COX I (cytochrome C oxidase subunit I) gene region of mitochondrial DNA, which is mainly used for species identification. The DNA barcode sequences were compared with the gene sequence of each fish registered in the US National Center for Biotechnology. A total of 46 processed seafood products (12 Pagrus majo, 4 Oplegnathus fasciatus, 7 Dentex tumifrons, 2 Acanthopagrus schlegelii, 7 Oreochromis niloticus, 6 Branchiostegus japonicus, 8 Branchiostegus albus) were investigated. Having DNA sequence identity of more than 97% was judged as the same species. As a result of this study, no cases of forgery and alteration were detected. However, some disparities in the commercial names used in local markets and the standard names given in the Korea Food Code were found, which may cause confusion for consumers. It is therefore suggested that the standard name or scientific name be displayed on seafood product labels.