• Journal of The Korean Society of Inherited Metabolic disease
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• v.24 no.1
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• pp.1-9
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• 2024

Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episode (MELAS) is a rare maternally inherited disorder primarily caused by mutations in mitochondrial DNA, notably the m.3243A>G mutation in the MT-TL1 gene. This mutation impairs mitochondrial function crucial for cellular energy production, particularly in high-energy-demanding organs such as the brain and muscles. MELAS manifests as recurrent stroke-like episodes, seizures, diabetes mellitus, cardiomyopathy, and other multisystemic symptoms that are often present in childhood. The diagnosis combines genetic testing, clinical evaluation, and neuroimaging, with elevated lactate levels and characteristic magnetic resonance imaging (MRI) findings as key indicators. Treatment focuses on symptomatic management and enhancement of mitochondrial function through L-arginine, coenzyme Q10, high-dose vitamins, and taurine supplementation. Studies have identified additional genetic variants linked to MELAS, including mutations in POLG and other mitochondrial genes, further complicating the genetic landscape. Emerging therapies, particularly gene therapy and mitochondria-targeting drugs, offer promising avenues for addressing the underlying genetic defects and improving mitochondrial functioning. Furthermore, ongoing studies continue to enhance our understanding and management of MELAS, with the aim of reducing its burden and improving patient outcomes and quality of life. This review summarizes the current knowledge on the genetics, clinical features, diagnosis, and treatment of MELAS, highlighting the latest advancements and future directions for therapeutic interventions.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.407-418
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• 2016

In this study, the phylogenetic relationship of Korean Hydrangea was evaluated by using sequenced three chloroplast regions and ITS region, including the 7 taxa. The result of phylogenetic analysis indicated that Korean Hydrangea, 7 taxa formed the monophyletic group. This analysis also revealed that subsect. Macrophyllae of Korea was separated into two groups; H. serrata f. acuminate and H. macrophylla group. The H. serrata f. acuminta group was included with H. serrata f. buergeri and H. serrata f. fertilis. These three species form a monophyletic clade, with no significant differences between their nucleotide sequences. The H. serrata f. acuminta group showed a monophyletic group with H. serrata f. buergeri and H. serrata f. fertilis and there is significant differences between their nucleotide sequences. H. macrophylla group was an independent clade distinguished by H. serrate f. acuminate group. Subsect. Petalanthe, Heteromallae and Calyptranthae form a monophyletic group. H. petiolaris which is located in Subsect. Calyptranthae was separated into two subgroups; First subgroup: Jeju island (except for Mt. Halla) and Second subgroup: Ulleung island and Japan. Additional studies of two subgroups of H. petiolaris should be conducted a geographical study and add more samples.

• Journal of Species Research
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• v.3 no.2
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• pp.127-166
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• 2014

Moniligastrids are an important yet often ignored earthworm group commonly found in cultivated soils, especially paddy, in the tropical East. Seven new taxa are: Drawida koreana austri, D. koreana nanjiro, D. koreana shindo, D. odaesan, D. jeombongsan, D. companio and D. csuzdii Blakemore spp. or sub-spp. nov. from Korea. Drawida csuzdii is the first new species from North Korea since Lumbricidae Eisenia koreana (Zicsi, 1972). Historical East Asian moniligastrids are reviewed chronologically and Drawida barwelli (Beddard, 1886), D. japonica (Michaelsen, 1892) and D. siemsseni Michaelsen, 1910 are compared on their museum types. These three taxa were thought similar and related to D. nepalensis Michaelsen, 1907 and its possible synonym D. burchardi Michaelsen, 1903 (priority!) and both of these to prior D. uniqua (Bourne, 1887). Indian Drawida calebi Gates, 1945 is compared to new material of D. japonica from Japan, and D. willsi Michaelsen, 1907 to the new sub-species of D. koreana Kobayashi, 1938 from Korea. Where available, mtDNA COI gene barcodes are provided to help objective determinations and a phylogram is provided with outgroup Ocnerodrilidae Eukerria saltensis (Beddard, 1895) itself found in rice paddy/irrigation. The challenge now is comparison of all early taxa in their various homelands in order to assess the genetic variability and taxonomic boundaries acceptable, especially for unpigmented D. barwelli and also for pink/grey D. japonica and blue/grey D. koreana. A checklist of moniligastrids is appended showing 22 species from China (including Hainan and Taiwan), 21 from Korea, nine from Japan and the Drawida ghilarovi Gates, 1969 species-complex from far eastern Russian (Siberia). Recent Drawida dandongensis Zhang & Sun, 2014 from Sino-Korean border is misdescribed and cannot be meaningfully compared to any other Drawidas.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.112-118
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• 2006

We report mitochondrial cytochrome b (cyt b) genes from greenling Hexagrammos otakii (Jordan et Starks) and spotty belly greenling, H. agrammus (Temminck et Schlegel) within Hexagrammidae, two species of aquaculture importance. Of 489 bp of the cytochrome b gene, a little variation occurred between species (96% similarity). The pairwise distance (0.0342) between greenling and spotty belly greenling in term of the Neighbor-joining method indicated that two species was close in molecular phylogenetic consideration. These findings are applicable to aquaculture, fisheries genetics and molecular phylogenetics in the genus Hexagrammos.

• Korean Journal of Poultry Science
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• v.39 no.4
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• pp.311-315
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• 2012

The increasing demand for Korean native chicken meat indicates that the discovery of haplotypes is very important from both economic and conservation points of view. In this study, mtDNA D-loop sequences from two crossbred Korean native chicken populations of 138 individuals were investigated. Twenty six nucleotide substitutions were identified from sequence analysis and were classified into 12 haplotypes. The haplotype H_8 represents 73.47% of Woorimatdag (chicken population) sequences, which were identified in all five Woorimatdag chicken populations investigated. The H_7 haplotype (Dhap1) for D population covers 45% sequences, which indicate maternal inheritance from black Korean native chicken. On the other hand, Chap3 and Chap4 for C population are specific haplotypes, as H_5 and H_2, respectively. Based on the network profiles, six SNPs (C199T, A239G, G242A, A291G, T330C and C391A) of the D-loop region are effective markers for discrimination between Woorimatdag and Hanhyup chicken populations. Also, the phylogenetic analyses of Woorimatdag and Hanhyup chicken populations were used to identify the genetic relationships among the haplotypes. The results presented here can be used for developing molecular markers to discriminate between two commercial Korean native chickens.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3863-3868
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• 2012

In this study mitochondrial D-Loop variations in Iranian prostate cancer and benign prostatic hyperplasia (BPH) patients were investigated. Tumour samples and corresponding non-cancerous prostate tissue from 40 prostate cancer patients and 40 age-matched BPH patients were collected. The entire mtD-loop region (16024-576) was amplified using the PCR method and products were gel-purified and subjected to direct nucleotide sequencing. A total of 129 variations were found, the most frequent being 263A${\rightarrow}$G and 310T${\rightarrow}$C among both BPH and prostate cancer patients. Variation of 309 C${\rightarrow}$T was significantly more frequent in prostate cancer patients (P value<0.05). Four novel variations were observed on comparison with the MITOMAP database. Novel variations were np16154delT, np366G${\rightarrow}$A, np389G${\rightarrow}$A and 56insT. There was no correspondence between the different variations and the age of subjects. Considering that D-loop variations were frequent in both BPH and prostate cancer patients in our study, the fact that both groups had high average age can be a possible contributing factor. D-loop polymorphisms and microsatellite instability can influence cell physiology and result in a benign or malignant phenotype. Significantly higher frequency of 309 C${\rightarrow}$T variation in cancer patients is a notable finding and must be a focus of attention in future studies.

• Animal cells and systems
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• v.6 no.1
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• pp.45-51
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• 2002

We compared the complete mitochondrial cytochrome b gene sequences of Korean and European cobitids to provide independent evidence for assessment of systematic and biogeographic relationships of species in the genus Cobitis. The data suggested monophyly of the genus Cobitis and the inclusion of Korean Cobitis species within the group having one lamina circularis, a primitive condition. Also, all the phylogenetic analyses using maximum parsimony, maximum likelihood, and neighbor joining methods showed a monophyletic relationship among Cobitis. The basal position of the Caspian C. cf. sibirica reported here reflects the eastern Asiatic origin cf. the European Cobitis and establishes C. cf. sibirica as an independent lineage. The Korean C. pacifica diverged next to C. cf. sibirica in basal group from the genus Cobitis. This result is in agreement with the hypothesized Asiatic origin of some European freshwater fish lineages. The phylogenetic relationships in this study showed a close affinity between C. zanadreai and C. sinensis. Two new species, C. tetralineata and C. pacifica in Korea also are closely related to monophyletic group clustering the type species of the Acanestrinia subgenus (C. elongata) with all the endemic Italian species (C. bilineata and C. zanandreai). This may suggest that the affinity between the Korean and Danubian-Italian imply genetic convergence or genetic plesiomorphic state between allopatric species that are separated for the Miocene. The mtDNA-based phylogeny for the species of the genus Cobitis from Kores and Europe permits phylogenetic assessment of the morphological transitions of Iamina circularis.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1993-1998
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• 2016

The effects of carbon-ion irradiation on cancer cell telomere function have not been comprehensively studied. In our previous report cancer cells with telomere dysfunction were more sensitive to carbon-ion irradiation, but the underlying mechanisms remained unclear. Here we found that telomerase activity was suppressed by carbon-ion irradiation via hTERT down-regulation. Inhibition of telomere activity by MST-312 further increased cancer cell radiosensitivity to carbon-ion radiation. hTERT suppression caused by either carbon-ion irradiation or MST-312 impaired mitochondrial function, as indicated by decreased membrane potential, mtDNA copy number, mitochondrial mass, total ATP levels and elevated reactive oxygen species (ROS). PGC-$1{\alpha}$ expression was repressed after carbion-ion irradiation, and hTERT inhibition by MST-312 could further exacerbate this effect. Lowering the mitochondrial ROS level by MitoTEMPO could partially counteract the induction of cellular senescence induced by carbon-ion radiation and MST-312 incubation. Taken together, the current data suggest that telomere-mitochondrion links play a role in the induction of senescence in MCF-7 cells after carbon-ion irradiation.

• Molecules and Cells
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• v.28 no.2
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• pp.105-109
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• 2009

We reported previously that overexpression of a salicylic acid (SA) methyltransferase1 gene from rice (OsBSMT1) or a SA glucosyltransferase1 gene from Arabidopsis thaliana (AtSAGT1) leads to increased susceptibility to Pseudomonas syringae due to reduced SA levels. To further examine their roles in the defense responses, we assayed the transcript levels of AtBSMT1 or AtSAGT1 in plants with altered levels of SA and/or other defense components. These data showed that AtSAGT1 expression is regulated partially by SA, or nonexpressor of pathogenesis related protein1, whereas AtBSMT1 expression was induced in SA-deficient mutant plants. In addition, we produced the transgenic Arabidopsis plants with RNAi-mediated inhibition of AtSAGT1 and isolated a null mutant of AtBSMT1, and then analyzed their phenotypes. A T-DNA insertion mutation in the AtBSMT1 resulted in reduced methyl salicylate (MeSA) levels upon P. syringae infection. However, accumulation of SA and glucosyl SA was similar in both the atbsmt1 and wild-type plants, indicating the presence of another SA methyltransferase or an alternative pathway for MeSA production. The AtSAGT1-RNAi line exhibited no altered phenotypes upon pathogen infection, compared to wild-type plants, suggesting that (an)other SA glucosyltransferase(s) in Arabidopsis plants may be important for the pathogenesis of P. syringae.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.189-195
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• 2006

We investigated the genetic variation in Stewartia koreana Nakai by examining 61 I-SSR amplicons in 120 individuals distributed among six natural populations in Korea. The overall percentage of polymorphic I-SSR amplicons was 81.9% and mean number of amplicons per I-SSR primer was 12.2. Levels of genetic diversity within 6 populations were similar each other[Shannon's Index $0.358{\sim}0.467$(mean: 0.407)]. The Mt. Obong population had the highest level of genetic diversity and was most distinctive from the other populations. Most variation existed among individuals within population(88.2%). Genetic differentiation among populations(${\phi}_{ST}$) was 0.118. The UPGMA dendrogram based on the genetic distance failed in showing decisive geographic relationships.