• Childhood Kidney Diseases
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• v.12 no.1
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• pp.1-10
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• 2008

Nucleic scids transfer the genetic information for serving a central biological purpose. The nucleic acids are polymers of nucleotides and they are mainly ribonucleic acid(RNA) and deoxyribonucleic acid(DNA). The nucleotides are stoichiometrically composed of five-carbon sugars, nitrogeneous bases, and phosphoric acids. The chemistry of nucleic acids and characteristics of different genomes are decribed for further study. Most of DNA genomes tend to be circular including bacterial genomes and eukaryotic mitochondrial DNA. Eukaryotic chromosomes in cells, in contrast, are generally linear. The ends of linear chromosomes are called telomeres. The genomes of different species, such as mammals, plants, invertebrates can be compared with the chromosome ends. The telomeric complex allows cells to distinguish the random DNA breaks and natural chromosomal ends. The very ends of chromosomes cannot be replicated by any ordinary mechanisms. The shortening of telomeric DNA templates in semiconservative replication is occurred with each cell division. The short telomere length is critically related to aging, tumors and dieases.

• Nutrition Research and Practice
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• v.11 no.2
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• pp.121-129
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• 2017

BACKGROUND/OBJECTIVES: The study was conducted to evaluate the effects of dietary leucine supplementation on mitochondrial biogenesis and energy metabolism in the liver of normal birth weight (NBW) and intrauterine growth-retarded (IUGR) weanling piglets. MATERIALS/METHODS: A total of sixteen pairs of NBW and IUGR piglets from sixteen sows were selected according to their birth weight. At postnatal day 14, all piglets were weaned and fed either a control diet or a leucine-supplemented diet for 21 d. Thereafter, a $2{\times}2$ factorial experimental design was used. Each treatment consisted of eight replications with one piglet per replication. RESULTS: Compared with NBW piglets, IUGR piglets had a decreased (P < 0.05) hepatic adenosine triphosphate (ATP) content. Also, IUGR piglets exhibited reductions (P < 0.05) in the activities of hepatic mitochondrial pyruvate dehydrogenase (PDH), citrate synthase (CS), ${\alpha}$-ketoglutarate dehydrogenase (${\alpha}$-KGDH), malate dehydrogenase (MDH), and complexes I and V, along with decreases (P < 0.05) in the concentration of mitochondrial DNA (mtDNA) and the protein expression of hepatic peroxisome proliferator-activated receptor-${\gamma}$ coactivator $1{\alpha}$ (PGC-$1{\alpha}$). Dietary leucine supplementation increased (P < 0.05) the content of ATP, and the activities of CS, ${\alpha}$-KGDH, MDH, and complex V in the liver of piglets. Furthermore, compared to those fed a control diet, piglets given a leucine-supplemented diet exhibited increases (P < 0.05) in the mtDNA content and in the mRNA expressions of sirtuin 1, PGC-$1{\alpha}$, nuclear respiratory factor 1, mitochondrial transcription factor A, and ATP synthase, $H^+$ transporting, mitochondrial F1 complex, ${\beta}$ polypeptide in liver. CONCLUSIONS: Dietary leucine supplementation may exert beneficial effects on mitochondrial biogenesis and energy metabolism in NBW and IUGR weanling piglets.

• Molecules and Cells
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• v.38 no.4
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• pp.356-361
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• 2015

Mitochondrial dysfunction is associated with insulin resistance and diabetes. We previously showed that retinoid X receptor ${\alpha}$ ($RXR{\alpha}$) played an important role in transcriptional regulation of oxidative phosphorylation (OXPHOS) genes in cells with mitochondrial dysfunction caused by mitochondrial DNA mutation. In this study, we investigated whether mitochondrial dysfunction induced by incubation with OXPHOS inhibitors affects insulin receptor substrate 1 (IRS1) mRNA and protein levels and whether $RXR{\alpha}$ activation or overexpression can restore IRS1 expression. Both IRS1 and $RXR{\alpha}$ protein levels were significantly reduced when C2C12 myotubes were treated with the OXPHOS complex inhibitors, rotenone and antimycin A. The addition of $RXR{\alpha}$ agonists, 9-cis retinoic acid (9cRA) and LG1506, increased IRS1 transcription and protein levels and restored mitochondrial function, which ultimately improved insulin signaling. $RXR{\alpha}$ overexpression also increased IRS1 transcription and mitochondrial function. Because $RXR{\alpha}$ overexpression, knock-down, or activation by LG1506 regulated IRS1 transcription mostly independently of mitochondrial function, it is likely that $RXR{\alpha}$ directly regulates IRS1 transcription. Consistent with the hypothesis, we showed that $RXR{\alpha}$ bound to the IRS1 promoter as a heterodimer with peroxisome proliferator-activated receptor ${\delta}$ ($PPAR{\delta}$). These results suggest that $RXR{\alpha}$ overexpression or activation alleviates insulin resistance by increasing IRS1 expression.

• Development and Reproduction
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• v.2 no.1
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• pp.39-43
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• 1998

The synthesis of steroid hormone starts from cholesterol. Steroidogenic acute regulatory protein(StAR) transfers cholesterol acutely from the outer mitochondrial membranes to the inner in the early step of steroidogenesis. Many kinds of steroid hormones are mainly synthesized in adrenal grand, ovary and testis. The purpose of this study is to determine the distribution of StAR mRNA in the rat ovary and adrenal gland and to confirm the functions of StAR in these organs. In the ovary, StAR mRNAs were strongly expressed in the corpus luteum, where progesterone is synthesized, and these were weakly expressed in the theca layer of follicles, where androgen is synthesized. However, StAR mRNAs were not detected in the estrogen producing granulosa cells of growing follicles. In the corpus luteum, StAR mRNAs were strongly loclized in the zona fasciculata and zona reticularis, where glucocorticoid is mainly synthesized. StAR mRNAs were weakly expressed in the zona gromerulosa, where mineralcorticoid is synthesized. StAR mRNAs were not detected in the adrenal medulla. In our results, StAR mRNAs were expressed differentially in the steroidogenic cells of ovary and adrenal gland according to the types of steroid hormones, and the statges of corpus luteum development. We conclude that StAR is involved in the steroidogenesis at the very early step of steroid synthesis cascade.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.226-239
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• 2021

Sebastes minor, Sebastes trivittatus, Sebastes owstoni, and Sebastes steindachneri are indigenous fish species inhabiting the central part of the East Sea, Korea. In order to understand the molecular evolution of these four rockfishes, we sequenced the complete mitochondrial genomes (mitogenomes) of S. minor and S. trivittatus. To further analyze the phylogeny of Sebastes species, the mitogenomes of 16 rockfishes were comparatively investigated. The complete mitochondrial DNA (mtDNA) nucleotide sequences of S. minor and S. trivittatus were 16,408 bp and 16,409 bp in length, respectively. A total of 37 genes were found in mtDNA of S. minor and S. trivittatus, including 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, which exhibited similar characters with other Sebastes species in the East Sea, Korea. In addition, we detected a conserved motif "ATGTA" in the control region of the four Sebastes species, but no tandem repeat units. Comparative analyses of the congeneric mitochondrial genomes were performed, which showed that control regions were more variable than the concatenated protein-coding genes. As a result of analysing phylogenetic relationships of four Sebastes species by using concatenated nucleotide sequences of 13 protein-coding genes, S. minor, S. trivittatus, S. owstoni and S. steindachneri were clustered into three clades. The phylogenetic tree exhibited that S. minor and S. steindachneri shared a closer relationship, whereas S. trivittatus and S. vulpes formed another distinct clade. Our results contribute to a better understanding of evolutionary patterns of Sebastes species inhabiting the middle East Sea, Korea.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.541-549
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• 2022

Potato late blight caused by Phytophthora infestans is a destructive disease in Korea. To elucidate the genomic variation of the mitochondrial (mt) genome, we assembled its complete mt genome and compared its sequence among different haplotypes. The mt genome sequences of four Korean P. infestans isolates were revealed by Illumina HiSeq. The size of the circular mt genome of the four major genotypes, KR_1_A1, KR_2_A2, SIB-1, and US-11, was 39,872, 39,836, 39,872, and 39,840 bp, respectively. All genotypes contained the same 61 genes in the same order, comprising two RNA-encoding genes, 16 ribosomal genes, 25 transfer RNA, 17 genes encoding electron transport and ATP synthesis, 11 open reading frames of unknown function, and one protein import-related gene, tatC. The coding region comprised 91% of the genome, and GC content was 22.3%. The haplotypes were further analyzed based on sequence polymorphism at two hypervariable regions (HVRi), carrying a 2 kb insertion/deletion sequence, and HVRii, carrying 36 bp variable number tandem repeats (VNTRs). All four genotypes carried the 2 kb insertion/deletion sequence in HVRi, whereas HVRii had two VNTRs in KR_1_A1 and SIB-1 but three VNTRs in US-11 and KR_2_A2. Minimal spanning network and phylogenetic analysis based on 5,814 bp of mtDNA sequences from five loci, KR_1_A1 and SIB-1 were classified as IIa-6 haplotype, and isolates KR_1_A2 and US-11 as haplotypes IIa-5 and IIb-2, respectively. mtDNA sequences of KR_1_A1 and SIB-1 shared 100% sequence identity, and both were 99.9% similar to those of KR_2_A2 and US-11.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.384-396
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• 2014

Vegetative compatibility groups (VCGs) are determined for many fungi to test for the ability of fungal isolates to undergo heterokaryon formation. In several fungal plant pathogens, isolates belonging to a VCG have been shown to share significantly higher genetic similarity than those of different VCGs. In this study we sought to examine the relationship between VCG and genetic similarity of an important cool season turfgrass pathogen, Sclerotinia homoeocarpa. Twenty-two S. homoeocarpa isolates from the Midwest and Eastern US, which were previously characterized in several studies, were all evaluated for VCG using an improved nit mutant assay. These isolates were also genotyped using 19 microsatellites developed from partial genome sequence of S. homoeocarpa. Additionally, partial sequences of mitochondrial genes cytochrome oxidase II and mitochondrial small subunit (mtSSU) rRNA, and the atp6-rns intergenic spacer, were generated for isolates from each nit mutant VCG to determine if mitochondrial haplotypes differed among VCGs. Of the 22 isolates screened, 15 were amenable to the nit mutant VCG assay and were grouped into six VCGs. The 19 microsatellites gave 57 alleles for this set. Unweighted pair group methods with arithmetic mean (UPGMA) tree of binary microsatellite data were used to produce a dendrogram of the isolate genotypes based on microsatellite alleles, which showed high genetic similarity of nit mutant VCGs. Analysis of molecular variance of microsatellite data demonstrates that the current nit mutant VCGs explain the microsatellite genotypic variation among isolates better than the previous nit mutant VCGs or the conventionally determined VCGs. Mitochondrial sequences were identical among all isolates, suggesting that this marker type may not be informative for US populations of S. homoeocarpa.

• Animal cells and systems
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• v.6 no.1
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• pp.13-18
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• 2002

Phylogenetic relationships of Korean Acidiella species were tested using mitochondrial 16S ribosomal RNA gene sequences. We used 16 published sequences as outgroup, and 10 new sequences for nine Korean Acidiella species as ingroup. The number of aligned sites was 1,281 bp, but 1,135 bp were used for the analysis after excluding sites with missing data or gaps. Among these 1,135 sites, 464 sites were variable and 340 were informative for parsimony analysis. Phylogenetic information was extracted from this data set using neighbor-joining, maximum likelihood and maximum parsimony methods and compared to a morphology-based phylogenetic hypothesis. Our molecular data suggest that: (1) the tribe Trypetini appears to be monophyletic even when the nine additional Acidiella species are added to our previous phylogenetic analysis; (2) all the Korean Acidiella species belong to the Trypeta group, but the genus Acidiella is not supported as monophyletic; (3) the close relationship of A. circumvaga, A. issikii, and A. sapporensis is supported; (4) the close relationship of A. pachypogon and two additional new Acidiella species is strongly supported; and (5) the possible presence of two or more cryptic species among the specimens previously identified as A. obscuripennis is suggested. Sequence data from the mitochondrial 16S rDNA allowed us to better understand the systematic status of Korean Acidiella species. They indicated that the current concept about the genus Acidiella is insufficient and needs to be refined further. This study also showed a few interesting relationships, that had not been recognized by morphological study alone. Based on this study, we were able to plan further experiments to analyze relationships within the Trypeta Group.

• 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.