• Genomics & Informatics
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• v.21 no.3
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• pp.39.1-39.15
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• 2023

DNA barcoding without assessing reliability and validity causes taxonomic errors of species identification, which is responsible for disruptions of their conservation and aquaculture industry. Although DNA barcoding facilitates molecular identification and phylogenetic analysis of species, its availability in clariid catfish lineage remains uncertain. In this study, DNA barcoding was developed and validated for clariid catfish. 2,970 barcode sequences from mitochondrial cytochrome c oxidase I (COI) and cytochrome b (Cytb) genes and D-loop sequences were analyzed for 37 clariid catfish species. The highest intraspecific nearest neighbor distances were 85.47%, 98.03%, and 89.10% for COI, Cytb, and D-loop sequences, respectively. This suggests that the Cytb gene is the most appropriate for identifying clariid catfish and can serve as a standard region for DNA barcoding. A positive barcoding gap between interspecific and intraspecific sequence divergence was observed in the Cytb dataset but not in the COI and D-loop datasets. Intraspecific variation was typically less than 4.4%, whereas interspecific variation was generally more than 66.9%. However, a species complex was detected in walking catfish and significant intraspecific sequence divergence was observed in North African catfish. These findings suggest the need to focus on developing a DNA barcoding system for classifying clariid catfish properly and to validate its efficacy for a wider range of clariid catfish. With an enriched database of multiple sequences from a target species and its genus, species identification can be more accurate and biodiversity assessment of the species can be facilitated.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.181-191
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• 2000

We have sequenced a portion of mitochondrial CO! gene (403 bp) of the firefly, Pyrocoelia rufa, to investigate genetic diversity within population, geographic variation, and phylogenetic relationships among haplotypes. A total of seven mtDNA haplotypes ranging in sequence divergence from 0.2% to 1.2% were obtained from 26 fireflies collected at four localities in Korea: Namhae, Pusan, Muju, and Yongin. The samples collected at the urban area, Pusan, were all fixed with one haplotype, differently those collected at the forest and/or agricultural areas. This appears to suggest that habitat fragmentation and population bottleneck caused by urbanization might have been severe in Pusan. On the other hand, from Muju known as the largest habitat and sanctuary for the firefly, four haplotypes with the maximum sequence divergence of 1.0% were obtained, and this estimate was the highest among the areas studied. The fireflies collected at the isolated islet, Namhae, revealed relatively low haplotype diversity(H=0.25), but one haplotype (PR7) was phylogenetically differentiated from others. This phenomenon was explained in terms of biogeographic history of the island and gene flow in the recent past. Grouping of Muju- Y ongin and Pusan-Namhae, respectively, in the hierarchical genetic analysis suggests the presence of historically occurred, biogeographic barrier against gene flow between them.

• Journal of Life Science
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• v.28 no.9
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• pp.1062-1067
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• 2018

Reliable labeling of fish products can reassure consumers regarding the identity and quality of seafoods. Therefore, techniques that can identify adulteration or mislabeling are valuable. To rapidly identify two Trachurus species, Trachurus japonicus and Trachurus novaezelandiae, a highly efficient, rapid, duplex polymerase chain reaction (PCR) having two species-specific primers simultaneously was identified. This species-specific primer focused on a single nucleotide mismatch in the 3'-terminal base of a primer designed in the mitochondrial cytochrome c oxidase (COI) subunit I DNA. To optimize the duplex PCR condition, gradient PCR reactions were conducted to determine the primer annealing temperature and the primer concentration. The PCR's product was observed on the gel, suggesting that DNA molecules may be useful in differentiating the two species. The length of the amplification fragments were 103 bp for Trachurus japonicus and 214 bp for Trachurus novaezelandiae, which, along with the species-specific primer visualized by agarose gel electrophoresis, enabled accurate distinction of the species of the Trachurus genus. These results indicate that the duplex PCR, which has a species-specific primer based on single nucleotide polymorphism (SNP), can be useful for rapidly differentiating the two species of Trachurus. This duplex PCR analysis is simple, rapid, and reliable, and could be beneficial to protecting consumers' rights.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1415-1420
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• 2000

Essential tremor(ET) is the most common movement disorder however there has been little agreement in the neurologic literature regarding diagnostic criteria for ET. Familial ET is an autosomal dominant disorder presenting as an isolated postural tremor. The main feature of ET is postural tremor of the arms with later involvement of the head, voice, or legs. In previous studies, it was reported that ET susceptibility was inherited in an autosomal dominant inheritance. As with previous results, it would suggest that ET might be associated with defect of mitochondrial or nuclear DNA. Recent studies are focusing molecular genetic detection of movement disorders, such as essential tremor and restless legs syndrome. Parkinson's disease(PD) is a neurodegenerative disease involving mainly the loss of dopaminergic neurons in substantia nigra by several factors. The cause of dopaminergic cell death is unknown. Recently, it has been suggested that Parkinson's disease many result from mitochondrial dysfunction. The authors have analysed mitochondrial DNA(mtDNA) from the blood cell of PD and ET patients via long and accurate polymerase chain reaction(LA PCR). Blood samples were collected from 9 PD and 9 ET patients. Total DNA was extracted twice with phenol followed by chloroform : isoamylalcohol. For the analysis of mtDNA, LA PCR was performed by mitochondrial specific primers. With LA PCR, 1/3 16s rRNA~1/3 ATPase 6/8 and COI~3/4 ND5 regions were observed in different patterns. But, in the COI~1/3 ATPase 6/8 region, the data of PCR were observed in same pattern. This study supports the data that ET and PD are genentic disorders with deficiency of mitochondrial DNA multicomplexes.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.1
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• pp.62-72
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• 2010

PM OLED is used in many applications as one of the display for the next generation. The most essential problems are the power dissipation and the short life time in applying PM OLED into a commercial application. Many efforts are made in developing the panel and in improving the circuit for expanding the current market wider. The life time in PM OLED is expanded by lessening the power dissipation of the circuit for the magnitude of the driving current is lowered. It is possible to minimize the power dissipation from improving the driving technology. The classical technology, Row-to-Row driving, is that row is selected one by one while applying the column current input individually. The multi-line driving is a new technology which is to select multiple rows simultaneously while applying the column current as a whole. However, the solution of the multi-line driving is NP-complete problem. The efficiency is dependant on the sort of picture and the driving condition. This paper presents the new efficient multi-line driving which is that the multiple lines are selected by applying column current together after grouping the simultaneous driving group applying the gnew efficient muthe coi-line dr coefficient. Bengrouping the several rows which has the higher coi-line dr coefficient, the more efficient driving is realized to present the high quality image and to lessen the power dissipation and to stretch the life time in the PM OLED.

• Journal of Life Science
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• v.26 no.9
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• pp.1007-1014
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• 2016

A highly efficient, rapid, and reliable multiplex polymerase chain reaction based method for distinguishing ten species of genus Cynoglossus (C. senegalensis, C. abbreviates, C. macrolepidotus, C. arel, C. semilaevis, C. interruptus, C. joyneri, C. lingua, C. robustus, and C. monodi) is described. The species-specific primer sets were designed base on the cytochrome oxidase subunit I gene (1,500 bp). The optimal PCR conditions and primers were selected for ten of Cynoglossus species to determine target base sequences using single PCR. Multiplex PCR using the ten pairs of primers either specifically amplified a DNA fragment of a unique size or failed, depending on each species DNA. The length of amplification fragment of 208 bp for C. senegalensis, 322 bp for C. abbreviates, 493 bp for C. macrolepidotus, 754 bp for C. arel, 874 bp for C. semilaevis, 952 bp for C. interruptus, 1,084 bp for C. joyneri, 1,198 bp for C. lingua, 1,307 bp for C. robustus, and 1,483 bp for C. monodi with the species-specific primers, visualized by agarose gel electrophoresis, allowed perfectly distinction of the Cynoglossus species. The multiplex PCR assay can be easily performed on multiple samples and attain final results in less than 6 hours. This technique should be a useful addition to the molecular typing tools for the tentative identification of Cynoglossus species.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.281-286
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• 2014

In grape vineyards, whitish spots in a cloud shape have been often observed on the fruit surface recently. However, the cause of the halo spot symptom was unknown, hindering countermeasures to be properly designed for the control. A small hole in the middle of the formless halo spot remained as a scar formed by oviposition of the thrips. It became later a suberized scab, which is separated from the epidermal cells on the surface either to be retained on or to be detached from it as time proceeds. Such a symptom is distinguished from the feeding damages caused by thrips or true bugs occurring on the grape fruits. With DNA extracted from the egg-shell found in the hole, molecular diagnosis by amplifying an ITS2 region with universal primers and subsequently digesting the PCR product by an restriction enzyme (RsaI) revealed that the egg was laid by Frankliniella occidentalis. In addition, a mitochondrial COI sequence confirmed that the halo spot symptom was formed by its oviposition. This study provides accurate information on the peculiar damage symptom caused by oviposition of F. occidentalis that could be useful in the control strategies for this pest in vineyards.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.471-475
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• 2016

The dark-winged fungus gnats are one of the most serious fly pests attacking the mushroom cultivation in Korea. They cause severe damage to the artificial sawdust beds used to cultivate mushroom, and reduce the production of button mushroom, Agaricus bisporus, in greenhouses. In this study, we collected nine species of the mushroom flies in order to identify the dominant species of the dark-winged fungus gnat attacking the A. bisporus plantation using the yellow sticky trap in Buyeo-gun, Boryeong-gun, Yongin-si and Chilgok-gun from April to June 2015. The collected samples were used to determine the DNA sequence of the cytochrome c oxidase subunit I (COI) of the nine different species by DNA barcoding. The sequencing results showed that Lycoriella ingenua was the dominant dark-winged fungus gnat species destroying A. bisporus cultivated on the artificial sawdust beds in Korea.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.469-477
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• 2012

Ostrinia larvae feed the pods and stem of red bean and seriously damage the bean production from farmers. In this study we investigated biological and developmental characteristics including field collection, host feeding preference, artificial rearing diet, morphological and molecular taxonomical identification, and pheromone analysis for an Ostrinia sp. in Korea. The male adults have massive tibia in the middle legs and 3-lobed uncus in the genitalia. The partial nucleotide sequences of mitochondrial cytochrome oxidase I (COI) and II (COII) were not corresponded to those DNA sequences from other Ostrinia species reported previously in Japan and China. Host plants for this species are also different from the previous species reported. In the gas chromatography (GC) analyses, (Z)-9-tetradecenyl acetate was not detected from the pheromone gland of our species while the component as a sex pheromone was found in O. zaguliaevi and O. zealis, With taken results, we conclude this Ostrinia species in Korea is Ostrinia scapulalis or closely related species. When larvae collected in a fall were incubated in the outdoor condition, they emerged to adult between June and July in the next year. The result indicates that the winter diapause could be started in late larval stage. In addition, we developed a semi-synthetic artificial diet adopted for mass rearing of the O. scapulalis in laboratory.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.352-358
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• 2018

This study aimed to develop a species identification method for the egg and fry of the three Korean bitterling fishes (Pisces: Acheilognathinae), including Acheilognathus signifer, Acheilognathus yamatsutae and Rhodeus uyekii based on the PCR-based Restriction Fragment Length Polymorphism (RFLP) markers. We conducted a field survey on the Deokchicheon River from the North Han River basin, where the three Acheilognathinae species co-occur, and also analyzed the existing sequence dataset available from the GenBank. We found coexistence of the three species at the study site. The egg and fry were obtained from the host mussels (Unio douglasiae sinuolatus) by hand from May to June 2015 and in May 2017. To develop PCR-based RFLP markers for species identification of the three Acheilognathinae fish species, restriction enzymes pinpointing species-specific single nucleotide variation (SNV) sites in mitochondrial DNA COI (cytochrome oxidase I) and cyt b (cytochrome b) genes were determined. Genomic DNA was extracted from the egg and fry and RFLP experiments were carried out using restriction enzymes Apal I, Stu I and EcoR V for A. signifer, A. yamatsutae and R. uyekii, respectively. Consequently, unambiguous discrimination of the three species was possible, as could be seen in DNA band patterns from gel electrophoresis. Our developed PCR-based RFLP markers will be useful for the determination of the three species for the young and would assist in studying the spawning patterns and reproductive ecology of Acheilognathinae fishes. Furthermore, we believe the obtained information will be of importance for future maintenance, management and conservation of these natural and endangered species.