• Journal of Life Science
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• v.29 no.9
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• pp.1034-1046
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• 2019

The mitochondria is the major cellular organelle of energy metabolism for the supply of cellular energy; it also plays an important role in controlling calcium regulation, reactive oxygen species (ROS) production, and apoptosis. Mitochondrial dysfunction causes various diseases, such as neurodegenerative diseases, Lou Gehrig's disease, cardiovascular disease, mental disorders, diabetes, and cancer. Most of the diseases are age-related diseases. In this review, we focus on the roles of mitochondrial dysfunction in cancer. Mitochondrial dysfunction induces carcinogenesis and is found in many cancers. The factors that cause mitochondrial dysfunction differ depending on the types of carcinoma, and those factors could cause cancer malignancy, such as resistance to therapy and metastasis. Mitochondrial dysfunction is caused by a lack of mitochondria, an inability to provide key substances, or a dysfunction in the ATP synthesis machinery. The main factor associated with cancer malignancy is mtDNA depletion. Mitochondrial dysfunction would leads to malignancy through changes in molecular activity or expression, but it is not known in detail which changes lead to cancer malignancy. In order to explore the relationship between mitochondrial dysfunction and cancer malignancy in detail, mitochondria dysfunctional cell lines are constructed using chemical methods such as EtBr treatment or gene editing methods, including shRNA and CRISPR/Cas9. Those mitochondria dysfunctional cell lines are used in the study of various diseases caused by mitochondrial dysfunction, including cancer.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.938-950
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• 2004

We used portions of mitochondrial 125 ribosomal RNA gene sequences (339 bp) to investigate the phylogenetic and population genetic characteristics of the Japanese anchovy, Engraulis japonicus, in Korean waters. A total of 35 mtDNA haplotypes were obtained from the samples collected in 3 locations (the southern area of the Yellow Sea, the western coast of Jejudo, and the eastern area of the South Sea) in Korean waters. One haplotype, AN8T103, obtained from the southern area of the Yellow Sea, was formed according to an independent phylogenetic individual in the PAUP analysis, which was separated from the others by a $0.2-4.1\%$ sequence divergence. This distinct haplotype appeared to be one that was carried by immigrants from another study area, but further study is necessary. Genetic divergence, except for AN8T103, was moderate to substantial $(0.2-3.8\%)$ and nucleotide diversity within populations was 0.015 for Yellow Sea, 0.013 for Jejudo, and 0.D15 for South Sea, respectively. The female gene flow was substantial or high (Nm=25.5-36.4), and the genetic distances between regions were not statistically significant $(P>0.01)$. These results indicated that the Japanese anchovy populations occurring in Korean waters were consisted of individuals randomly dispersed over geographic areas.

• Molecules and Cells
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• v.39 no.7
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• pp.543-549
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• 2016

MicroRNAs (miRNAs) have been reported to be involved in many neurodegenerative diseases. The present study focused on the role of hsa-miR-144-3p in one of the neuro-degenerative diseases, Parkinson's disease (PD). Our study showed a remarkable down-regulation of miR-144-3p expression in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-treated SH-SY5Y cells. MiR-144-3p was then overexpressed and silenced in human SH-SY5Y cells by miRNA-mimics and miRNA-inhibitor transfections, respectively. Furthermore, ${\beta}$-amyloid precursor protein (APP) was identified as a target gene of miR-144-3p via a luciferase reporter assay. We found that miR-144-3p overexpression significantly inhibited the protein expression of APP. Since mitochondrial dysfunction has been shown to be one of the major pathological events in PD, we also focused on the role of miR-144-3p and APP in regulating mitochondrial functions. Our study demonstrated that up-regulation of miR-144-3p increased expression of the key genes involved in maintaining mitochondrial function, including peroxisome proliferator-activated receptor ${\gamma}$ coactivator-$1{\alpha}$(PGC-$1{\alpha}$), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM). Moreover, there was also a significant increase in cellular ATP, cell viability and the relative copy number of mtDNA in the presence of miR-144-3p overexpression. In contrast, miR-144-3p silencing showed opposite effects. We also found that APP overexpression significantly decreased ATP level, cell viability, the relative copy number of mtDNA and the expression of these three genes, which reversed the effects of miR-144-3p overexpression. Taken together, these results show that miR-144-3p plays an important role in maintaining mitochondrial function, and its target gene APP is also involved in this process.

• Journal of Life Science
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• v.26 no.7
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• pp.749-757
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• 2016

This study was carried out to reveal the genetic population structure of the Jeju Island population and the phylogenetic relationship of East Asian populations of the large-footed bat (Myotis macrodactylus) based on the genetic polymorphisms of mitochondrial cytochrome B (CYTB) and NADH dehydrogenase subunit 1 (ND1) gene sequences. A total of fourteen and nine haplotypes were found in the CYTB and ND1 sequences from East Asian bats, respectively. Haplotype distribution showed locality specific patterns. The results from ND1 haplotype analysis showed that the Jeju Island population has four haplotypes: the Mt. Halla and Western subpopulations have three ND1 haplotypes, but the Eastern subpopulation has just a single haplotype Nd03, which is commonly found on this island. The neighbor-joining (NJ) tree showed the closer relationship between Jeju Island and Japan rather than that between Jeju and Gangwon-do Province. The divergence time between the maternal ancestor lineages of Japanese and Chinese populations was estimated to be 0.789±0.063 MYBP. The secondary divergence between Jeju and Japanese bats was calculated about to be 0.168±0.013 MYBP. The Jeju population has immigrated to the island at least fifty thousand years ago. In addition, ND1 haplotype analysis suggested that the insular bats have experienced at least two further genetic differentiation events within this island. Consequently, these findings suggested that the results of this study may play a critical role in understanding the phylogenetic relationship among East Asian bat populations of M. macrodactylus. To prepare more explainable information on evolutionary correlation, analysis is still required to examine using expanded samples from China, Russia, and southern parts of the Korean Peninsula.

• Ocean and Polar Research
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• v.36 no.2
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• pp.189-197
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• 2014

The pearl-spot damsel, Chromis notata, is one of the important fishery species in Korea. While C. notata has been commonly harvested in southern Korea, the increasing number of C. notata in higher latitudes has crucial ecological, economic and evolutionary implications under conditions where the climate is rapidly changing. Here we examined the morphological and genetic characteristics of C. notata to assess patterns of geographical variations among the groups from three different sites. The groups were clearly distinguishable in the analysis of morphological characteristics. On the other hand, the groups were genetically indistinguishable. All individuals fell within a single clade in the neighbor-joining tree but appeared scattered in the haplotype network. Several haplotypes are shared among the sampling sites (Jejudo-Ulleungdo; Hap 9, Wangdolcho-Ulleungdo; Hap 28, Hap 33, Hap 34). Although control region markers did not elucidate the spatial patterns in genetic characteristics, Wangdolcho and Ulleungdo groups appear to exhibit a more robust gene flow between the two groups than with Jejudo group. Integrative approaches such as those combining morphological and genetic analyses minimize potential errors caused by limited perspectives of each analysis and can provide useful information for discovering functional DNA regions attributable to morphological characteristics expressions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.146-153
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• 2022

The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.281-289
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• 2019

Since 2013, more than 100 Entoloma (Entolomataceae, Agaricales) collections have been made during field investigations of mushroom flora in Korea. Among these collections, three Entoloma species were identified as new records from Korea. Morphological examinations were made based on the macro- and micro-morphological features of the isolates collected during field visits. To ensure the identity of the isolates at the species level, DNA sequences from four gene regions (rpb2, ITS, 28S, and mtSSU) were compared. To the best of our knowledge, these are the first records of E. aprile, E. chytrophilum, and E. hirtipes in Korea. Comprehensive descriptions, photographs, and phylogenetic examinations are presented here.

• Animal Systematics, Evolution and Diversity
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• v.29 no.2
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• pp.184-187
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• 2013

Korean species of the genus Elampus Spinola is taxonomically reviewed. Korean fauna of the genus Elampus was known by one sepcies, Elampus bidens (F$\ddot{o}$rster). This study reports new discover of another Korean species E. musashinus (Tsuneki). This species was described based on male, and the female has been still unknown. With comparison of partial mitochondrial cytochrome c oxidase I gene sequences, the sex-association of this species is established, the Korean specimens of both sexes completely identical in their sequences targeted. Herein the female description of E. musashinus is presented for the first time. A key to the Korean species, as well as diagnosis and digital images are provided.

• Journal of Species Research
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• v.12 no.3
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• pp.240-243
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• 2023

The genus and species, Diekeana insignis(Gorham), is reported for the first time in Korea. Male adults were collected from Geoje Island and Changwon-si, located in the southern part of South Korea. The species of D. insignis(Gorham) is characterized by the following morphological characteristics: body length about 9.4mm; pronotum with transverse black marking in the middle part; each elytron with seven large black markings; penis long, slightly bent at apical part, truncate at apex; parameres narrow and as long as penis guide; penis guide narrow and pointed at apex. We herein provide habitus photographs, illustrations of morphological characters, male genitalia, and a detailed diagnosis. A partial sequence of the mitochondrial COI gene was obtained and provided mtDNA information for this species.

• Journal of Species Research
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• v.12 no.1
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• pp.27-37
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• 2023

Kushia zosteraphila Harris V.A. & Iwasaki, 1996 is newly collected and described from macroalgae in the intertidal region of Gijang-gun, along the southeastern coastal region of Korea. Kushia zosteraphila can be distinguished from congeners by following morphological characteristics: the length of the first dorsal seta similar with the second dorsal seta of female P5, the length to width ratio of the female caudal ramus, and the presence of a conspicuous comb on the accessory lobe of the male antennule. Although there are some minor discrepancies, the main diagnostic characteristics of the specimen from the study area are well-matched with the original description. We herein provide detailed morphological descriptions and illustrations of this species. According to a survey of the location of the reported porcellidiid species in Korea, this specimen is the second record in Korean waters of the genus Kushia. A key to species of the family Porcellidiidae in Korea is provided. A partial sequence of the mitochondrial COI gene was obtained and provided as a DNA barcode for this species.