• Molecules and Cells
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• v.46 no.4
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• pp.219-230
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• 2023

Down syndrome (DS) is the most common autosomal aneuploidy caused by trisomy of chromosome 21. Previous studies demonstrated that DS affected mitochondrial functions, which may be associated with the abnormal development of the nervous system in patients with DS. Runt-related transcription factor 1 (RUNX1) is an encoding gene located on chromosome 21. It has been reported that RUNX1 may affect cell apoptosis via the mitochondrial pathway. The present study investigated whether RUNX1 plays a critical role in mitochondrial dysfunction in DS and explored the mechanism by which RUNX1 affects mitochondrial functions. Expression of RUNX1 was detected in induced pluripotent stem cells of patients with DS (DS-iPSCs) and normal iPSCs (N-iPSCs), and the mitochondrial functions were investigated in the current study. Subsequently, RUNX1 was overexpressed in N-iPSCs and inhibited in DS-iPSCs. The mitochondrial functions were investigated thoroughly, including reactive oxygen species levels, mitochondrial membrane potential, ATP content, and lysosomal activity. Finally, RNA-sequencing was used to explore the global expression pattern. It was observed that the expression levels of RUNX1 in DS-iPSCs were significantly higher than those in normal controls. Impaired mitochondrial functions were observed in DS-iPSCs. Of note, overexpression of RUNX1 in N-iPSCs resulted in mitochondrial dysfunction, while inhibition of RUNX1 expression could improve the mitochondrial function in DS-iPSCs. Global gene expression analysis indicated that overexpression of RUNX1 may promote the induction of apoptosis in DS-iPSCs by activating the PI3K/Akt signaling pathway. The present findings indicate that abnormal expression of RUNX1 may play a critical role in mitochondrial dysfunction in DS-iPSCs.

• Journal of Life Science
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• v.26 no.10
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• pp.1137-1152
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• 2016

Cells sense, respond, and adapt to a low oxygen environment called hypoxia, which is widely involved in a variety of human diseases. Adaptation to low oxygen concentrations includes gene expression changes by inducing hypoxic genes and reducing aerobic genes. Recently, the mitochondrial respiratory chain has been implicated in the control of these oxygen-regulated genes when cells experience hypoxia. In order to obtain an insight into an effect of the mitochondrial respiratory chain on cellular response to hyxpoxia, we here examined whole genome transcript signatures of respiration-proficient and respiration-deficient budding yeasts exposed to hypoxia using DNA microarrays. By comparing whole transcriptomes to hypoxia in respiration-proficient and respiration-deficient yeasts, we found that there are several classes of oxygen-regulated genes. Some of them require the mitochondrial respiratory chain for their expression under hypoxia while others do not. We found that the majority of hypoxic genes and aerobic genes need the mitochondrial respiratory chain for their expression under hypoxia. However, we also found that there are some hypoxic and aerobic genes whose expression under hypoxia is independent of the mitochondrial respiratory chain. These results indicate a key involvement of the mitochondrial respiratory chain in oxygen-regulated gene expression and multiple mechanisms for controlling oxygen-regulated gene expression. In addition, we provided gene ontology analyses and computational promoter analyses for hypoxic genes identified in the study. Together with differentially regulated genes under hypoxia, these post-analysis data will be useful resources for understanding the biology of response to hypoxia.

• Animal Systematics, Evolution and Diversity
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• v.22 no.1
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• pp.87-89
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• 2006

The mitochondrial cytochrome b gene of the Korean subspecies (Falco tinnunculus interstinctus) of the common kestrel has been analyzed. According to the molecular phylogeny of six subspecies of common kestrel, six subspecies of the common kestrel were divided into two clades: the first clade is composed of the South African subspecies (F. t. rupicolus) and the second clade includes 5 subspecies (F. t. tinnunculus, F. t. rufescens, F. t. interstinctus, F. t. canariensis and F. t. dacotiae) of the common kestrel. Korean subspecies, F. t. interstinctus was closely related to F. t. rufescens and original subspecies F. t. tinnunculus.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.11
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• pp.1552-1556
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• 2005

The UCPs are members of the mitochondrial inner membrane transporter family, present in the mitochondrial inner membrane. Their main function is increasing the energy expenditure via diminishing the resulting production of ATP from mitochondrial oxidative phosphorylation instead of yielding dissipative heat. They are associated with the metabolism of fat and regulation of energy expenditure. The UCP gene can be viewed as the candidate gene for chicken fatness. In the present study, RT-PCR and Northern Blot methods were developed to investigate the expression of the UCP gene in ten tissues including heart, liver, spleen, lung, kidney, gizzard, intestine, brain, breast muscle and abdominal fat of chicken. The results of both RT-PCR and Northern Blot methods showed that the UCP gene expressed specific in breast muscle. The expression levels of UCP gene in breast muscles from egg-type and meat-type chickens of hatching, 2, 4, 6 and 8 wk of age were detected by RT-PCR assay and results showed that the expression levels of UCP gene were related to breeds. Expression level of UCP gene in layers was higher than that in broilers at various weeks of age except at 6 wk. The UCP gene's expression was higher at 6 wk and had no significant difference among other weeks of age in broilers; in layers the expression level of UCP gene had no significant difference among weeks of age. The experiment results also showed that insulin could increase the expression level of UCP gene by 40% compared with control group.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.94-99
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• 2003

Mitochondrial DNAs has been used frequently as genetic markers for the population genetic studies of salmonid fishes. Samples used in this experiment were chum salmons (Oncorhynchus keta) from Korea. We analyzed variation of mitochondrial NADH dehydrogenase subunit 3 gene (ND3) among 4 individuals of the Korea population. Genomic DNA was extracted from the liver of the chum salmon samples. Then, the ND3 gene was amplified by polymerase chain reaction (PCR) including the 3' region of cytochrome oxidase III gene (COIII) and the 5` region of NADH dehydrogenase subunit 4L gene (ND4L). The size of the PCR product was 752 Up and the sequences showed some genetic variation among those four individuals. Genetic variations were observed in 7 sites as single nucleotide polymorphism (SNP). Within the open reading frame of the ND3 gene which encodes 116 amino acids, 5 nucleotide substitutions were found. Both transitional and transversional changes occurred more frequently with transitional changes. Comparison of these sequences with the others of a Japanese chum salmon in GenBank showed 5 sites of SNPs. This study provided the basic information of SNP in ND3 gene among Korean chum salmons and demonstrated the possible use of the SNP data as a genetic marker.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.365-368
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• 2006

Yeast mitochondrial transformation has been confirmed by cell death and CFP expression (CDF: cell death factor gene). Expression vector containing CDF and CFP driven by one TPI (Triose-phosphate isomerase) promoter (called artificial operon type) was bombarded to Yeast. Interestingly, yeast cells were progressively deformed into unusual shapes and lysed inner cytoplasm resulting in ell death after all after bombarding with expression vector (CDC and GFP). Since there is no report about more than one gene expression simultaneously in a single mitochondria, this report is very important to novel type of eukaryotic gene expression. Successful yeast cell transformation in this report implies possible eukaryotic mitochodrial transformation including plants and animals and moreover two or more gene expression which can be excellent applicable protocols to pharmaceutical field including antibody production.

• ALGAE
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• v.33 no.1
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• pp.49-54
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• 2018

Red algal mitochondrial genomes (mtDNAs) can provide useful information on species identification. mtDNAs of Pyropia / Porphyra (Bangiales, Rhodophyta) have shown diverse variation in their size and gene structure. In particular, the introns and intronic open reading frames found in the ribosomal RNA large subunit gene (rnl) and cytochrome c oxidase subunit 1 gene (cox1) significantly vary the mitochondrial genome size in Pyropia / Porphyra species. In this study, we examined the exon / intron structure of rnl and cox1 genes of Pyropia yezoensis at the intraspecific level. The combined data of rnl and cox1 genes exhibited 12 genotypes for 40 P. yezoensis strains, based on the existence of introns. These genotypes were more effective to identify P. yezoensis strains in comparison to the traditional DNA barcode cox1 marker (5 haplotypes). Therefore, the variation in gene structure of rnl and cox1 can be a novel molecular marker to discriminate the strains of Pyropia species.

• Journal of Aquaculture
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• v.10 no.4
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• pp.403-407
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• 1997

Intraspecific sequence variation was detected by polymerase chain reaction (PCR) and direct sequencing of a 350-nucleotide region of the mitochondrial 12S rRNA gene of two natural populations (Han River and Nakdong River) and one hatchery stock (Jinhae Inland Fisheries Institute) of local strain common carp, one Israeli strain of common carp stock from Pukyong National University (PKU), and one hybrid between Israeli strain of common carp female and local strain common carp male from PKU stock. There is little variation in 350 bases of the mitochondrial 12S rRNA gene sequences among 2 natural and 1 hatchery local strain common carp populatins, representing abut 7 to 20 nucleotide differences (less than 6%). The sequence of specimens from Han River was more similar to that from Nakdong River (identity=98.0%) than to that from Jinhae Inland Fisheries Institute (identity=96.3%). Sequence variation between Israeli strain and wild local strain common carp was higher than the variation within natural stocks. The level of variation was ranged from 15.7 to 17.7%. The hybrid showed very similar nucleotide4 sequence of 12S rRNA gene to the sequence of Israeli strain with the identity of 98.9%.

• Molecules and Cells
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• v.28 no.3
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• pp.155-165
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• 2009

The newly sequenced complete mitochondrial genome of the brown marmorated stink bug, Halyomorpha halys($St{\aa}l$) (Hemiptera: Pentatomidae), is a circular molecule of 16,518 bp with a total A+T content of 76.4% and two extensive repeat regions in A+T rich region. Nucleotide composition and codon usage of H. halys are about average when compared with values observed in 19 other published hemipteran mitochondrial genomes. Phylogenetic analyses using these 20 hemipteran mitochondrial genomes support the currently accepted hypothesis that suborders Heteroptera and Auchenorrhyncha form a monophyletic group. The mitochondrial gene arrangements of the 20 genomes are also consistent with our results.

• Biomedical Science Letters
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• v.18 no.2
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• pp.112-122
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• 2012

A gradual change of molecules that are related in fission and fusion is occurred during aging process. Although aging effects on mitochondrial fusion and fission are investigated, it is still unclear that the extent of the change in mitochondria fusion and fission periodically. In this study we investigated the changes of mitochondrial proteins involved in fusion (Mfn2, Opa1) and fission (Drp1, Fis1) in the human gracilis muscle ranging from 10 to 50 years of age (n=40). The gracilis muscle showed a significant increase in muscle apoptotic changes in the age of 50s compared with 10s by using in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). The expression levels of Drp1 and Fis1 (P<0.01, P<0.05) mRNA were significantly elevated and the Mfn2 and Opa1 (P<0.01, P<0.05) levels were decreased from older individuals. The ratio of fission and fusion was altered and the level of increment of fission gene was greater than fusion gene decrement in the age of 50s. These findings suggest that changes of mitochondrial fusion and fission proteins related with aging might contribute to aged muscle apoptosis.