• Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.101-106
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• 2006

The cytochrome c oxidase subunit I (COI) gene region of mitochondrial DNA (mtDNA) was examined in four abalone species to estimate its utility as a genetic marker using restriction fragment length polymorphism (RFLP) analysis. The utility was evaluated in terms of genetic divergence and relationships among Haliotis discus hannai, H. rufescens, H. rubra, and H. midae in both hemispheres of the world. There was clear genetic divergence in the mtDNA COI region between all pairs of the four species. Moreover, relationships among the abalone species were reflected in their geographical distributions and morphological characteristics. Therefore, RFLP analysis of the mtDNA COI region is a suitable genetic marker for the estimation of genetic divergence and relationships among abalone species. However, it is not effective for the evaluation of genetic differences within abalone species.

• Animal Systematics, Evolution and Diversity
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• v.36 no.1
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• pp.7-9
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• 2020

In the present study, the first mitochondrial cytochrome c oxidase subunit I gene (COI) sequence of Sterkiella multicirrata Li et al., 2018 is presented. To begin with, this species has been also morphologically recorded from South Korea, and this study was performed using genomic DNA of the Korean population. The newly obtained COI sequences of S. multicirrata were identical. And the inter-specific variation between S. multicirrata and S. histriomuscorum was noted at 14.3%. These values correspond well with the results of previous studies. However, because there are very few available COI sequences of stichotrichian in GenBank, it is concluded that continuous accumulation of data is needed for further study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.830-833
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• 2003

This paper describes the fabrication and characteristics of 3C-SiCOI sotctures by SDB and etch-back technology for high-temperature MEMS applications. In this work, insulator layers were formed on a heteroepitaxial 3C-SiC film grown on a Si(001) wafer by thermal wet oxidation and PECVD process, successively. The pre-bonding of two polished PECVD oxide layers made the surface activation in HF and bonded under applied pressure. The wafer bonding characteristics were evaluated by the effect of HF concentration used in the surface treatment on the roughness of the oxide and pre-bonding strength. Hydrophilic character of the oxidized 3C-SiC film surface was investigated by ATR-FTIR. The strength of the bond was measured by tensile strengthmeter. The bonded interface was also analyzed by SEM. The properties of fabricated 3C-SiCOI structures using etch-back technology in TMAH solution were analyzed by XRD and SEM. These results indicate that the 3C-SiCOI structure will offers significant advantages in the high-temperature MEMS applications.

• Animal Systematics, Evolution and Diversity
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• v.28 no.4
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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.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.157-168
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• 2000

Sea urchin S. intermedius occurring in the Korean east coast is a cold water species that belongs to the family Strongylocentrotidae of Echinoidea. Although it is known that there are nine species in the family, species identification criteria, phylogenetic relationships, time and process of evolution of the family members have not been uncovered clearly. In the present study, I tried to find some clues to such problems for S. intermedius by means of DNA sequences. For this, cytochrome c oxidase subunit I (COI), one of the mitochondrial genes that evolve fast and follow maternal inheritance was analyzed. DNA was extracted from the female gonad of S. intermedius, a segment of COI gene amplified by polymerase chain reaction (PCR), and finally a total of 1077 base pair sequence of COI obtained by cloning and sequencing the PCR product. The sequence was compared with homologous genes of other sea urchins and echinoderm species. Phylogenetic trees of the COI gene segment revealed that S. intenedius is a sister species of S. purpuratus which lives along the east coast of the Paciflc. With reference to the fossil records of sea urchins and genetic distances in the molecular phylogenies, it is estimated that the two species were separated about 0.89 million years ago when the earth temperature fluctuated significantly. The current disjunct distribution patterns of the two species and the climate change of the earth at the time of separation suggest that speciation might have occurred by vicariance. The COI gene sequence obtained here now can be used as a molecular character which discerns S. intermedius from the other sea urchin species of Strongylocentrotidae.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.318-327
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• 2007

This study presents the molecular phylogenetic analysis of Korean Aurelia aurita Linnaeus collected from Yeosu in the southern waters of Korea using nuclear ITS1 region and mitochondrial COI gene sequences. The use of oligonucleotide primers F5 (forward) and R5 (reverse) targeted to ITS1 and LCO1490 (forward) and HCO2198 (reverse) targeted to COI amplified 267 bp and 643 bp fragments, respectively. The shortest genetic distance towards the ITS1 region is estimated at 0.023 when comparing Korean A. aurita to Aurelia sp. collected from California, USA. In particular, Korean and American/Swedish A. aurita were located far away in terms of genetic distance, ranging from 0.393 to 0.395. On the other hand, the genetic distance between Korean and English/Turkish/Swedish/American A. aurita regarding the mitochondrial DNA COI gene ranged from 0.201 to 0.205. However, a sister-ship with Korean and American A. aurita showed an extremely high bootstrap value (100%). The predicted secondary RNA structure of the mitochondrial DNA COI gene showed many different folding structures with a similar energy between Korean and American A. aurita. These results suggest that ITS1 and the mitochondrial DNA COI gene could be used as genetic markers for identification of the biogeographic populations.

• Korean journal of applied entomology
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• v.56 no.2
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• pp.107-120
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• 2017

Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the most important insect pests in the world. In the present study, the taxonomic status of B. tabaci and the number of species composing the B. tabaci complex were determined based on 550 COI gene sequences of B. tabaci. Genetic divergence within B. tabaci ranged from 0% to 27.8% (average 11.1%). This result indicates that the B. tabaci complex is composed of multiple species that may belong to different genera or subfamilies. A phylogenetic tree constructed based on 217 COI gene sequences without duplications revealed that the B. tabaci complex is composed of a total of 43 putative species, including a new species, Java. In addition, genetic divergence within nine species (Australia, Asia II 1, Asia II 6, Asia II 7, Asia II 10, Mediterranean, New world, New world 2, Sub Saharan Africa 1) indicates that 4.0% is reasonable to be used as a threshold of species boundaries within the B. tabaci complex, and species with high intraspecific genetic divergences can be related with cryptic species.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.287-290
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• 2009

A natural hybrid between the striped spine loach Cobitis tetralineata and the king spine loach Iksookimia longicorpa was genetically identified by sequence analyses of nuclear recombination activating gene 1 (RAG1) and mitochondrial cytochrome c oxidase I (COI) genes. Out of 850 base positions of RAG1, a total of 23 nucleotide substitutions were detected between the two parental species, whereas the electropherogram of the natural hybrid displayed double peaks at all of the 23 positions, which reflects their simple Mendelian inheritance pattern. Meanwhile, comparison of partial sequences of mitochondrial genes (COI in this study), which are well characterized by the maternal inheritance pattern, revealed that the maternal species of the hybrid was C. tetralineata because of their 100% sequence identity.

• International Journal of Industrial Entomology and Biomaterials
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• v.36 no.2
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• pp.31-41
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• 2018

The dung beetle, Copris tripartitus (Coleoptera: Scarabaeidae), is an endangered insect in South Korea. Previously, partial mitochondrial COI and CytB gene sequences have been used to infer genetic diversity and gene flow of this species in South Korea. In this study, we additionally collected C. tripartitus (n = 35) from one previous locality and two new localities, sequenced COI and CytB genes, and combined these with preexisting data for population genetic analysis. Sequence divergence of current samples showed slightly lower values [4.86% (32 bp) for COI and 4.16% (18 bp) for CytB] than that in the previous study. Nucleotide diversity (${\pi}$) ranged from 0.005336 (Gulupdo) to 0.020756 (Seogwi-dong) in COI and 0.009060 (Aewol-eup) to 0.017464 (Seogwi-dong) in CytB. Seogwi-dong samples that showed the highest ${\pi}$ in the previous study also showed the highest ${\pi}$ in this study for both gene sequences. The newly investigated Gulupdo samples had the lowest haplotype diversity for both gene sequences. They also had the lowest ${\pi}$ for COI and the second lowest ${\pi}$ for CytB. On the other hand, the newly added Haean-dong sample had relatively higher diversity estimates. Gene flow among populations was high, although significant difference was only detected between Gulupdo and Anmado or between Gulupdo and Seogwi-dong for COI sequences (P < 0.05). Considering the high genetic diversity and gene flow in C. tripartitus populations, one major issue regarding conservation seems not to be recovery of genetic diversity.

• Animal Systematics, Evolution and Diversity
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• v.29 no.4
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• pp.272-278
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• 2013

Accurate identification of fish and fish products, from eggs to adults, is important in many areas. Grey mullets of the family Mugilidae are distributed worldwide and inhabit marine, estuarine, and freshwater environments in all tropical and temperate regions. Various Mugilid species are commercially important species in fishery and aquaculture of many countries. For the present study we have chosen two Mugilid genes with different phylogenetic signals: relatively variable mitochondrial cytochrome oxidase subunit I (COI) and conservative nuclear rhodopsin (RHO). We examined their diversity within and among 9 Mugilid species belonging to 4 genera, many of which have been examined from multiple specimens, with the goal of determining whether DNA barcoding can achieve unambiguous species recognition of Mugilid species. The data obtained showed that information based on COI sequences was diagnostic not only for species-level identification but also for recognition of intraspecific units, e.g., allopatric populations of circumtropical Mugil cephalus, or even native and acclimatized specimens of Chelon haematocheila. All RHO sequences appeared strictly species specific. Based on the data obtained, we conclude that COI, as well as RHO sequencing can be used to unambiguously identify fish species. Topologies of phylogeny based on RHO and COI sequences coincided with each other, while together they had a good phylogenetic signal.