• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1290-1296
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• 2020

Recently, it was reported that entire mammalian mtDNA genomes could be transplanted into the mitochondrial networks of yeast, where they were accurately and stably maintained without rearrangement as intact genomes. Here, it was found that engineered mtDNA genomes could be readily transferred to and steadily maintained in the mitochondria of genetically modified yeast expressing the mouse mitochondrial transcription factor A (Tfam), one of the mitochondrial nucleoid proteins. The transferred mtDNA genomes were stably retained in the Tfam-expressing yeast cells for many generations. These results indicated that the engineered mouse mtDNA genomes introduced in yeast mitochondria could be relocated into the mitochondria of other cells and that the transferred genomes could be maintained within a mitochondrial environment that is highly amenable to mimicry of the biological conditions in mammalian mitochondria.

• Genomics & Informatics
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• v.8 no.2
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• pp.86-89
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• 2010

Closely related species share large genomic segments called syntenic regions, where the genomic elements such as genes are arranged co-linearly among the species. While synteny is an important criteria in establishing orthologous regions between species, non-syntenic regions may display species-specific features. As the first step in cataloging human- or primate- specific genomic elements, we surveyed human genomic regions that are not syntenic with any other non-primate mammalian genomes sequenced so far. Based on the data compiled in Ensembl databases, we were able to identify 10 such regions located in eight different human chromosomes. Interestingly, most of these highly human- or primate- specific loci are concentrated in subtelomeric or pericentromeric regions. It has been reported that subtelomeric regions in human chromosomes are highly plastic and filled with recently shuffled genomic elements. Pericentromeric regions also show a great deal of segmental duplications. Such genomic rearrangements may have caused these large human- or primate- specific genome segments.

• Genomics & Informatics
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• v.3 no.2
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• pp.52-54
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• 2005

Visualization of the homology information is an important method to analyze the evolutionary and functional meanings of genes. With a database containing model genomes of Homo sapiens, Mus muculus, and Rattus norvegicus, we constructed a web­based comparative analysis tool, BioCovi, to visualize the homology information of mammalian sequences on a very large scale. The user interface has several features: it marks regions whose identity is greater than that specified, it shows or hides gaps from the result of global sequence alignment, and it inverts the graph when total identity is higher than the threshold specified.

• Journal of Plant Biotechnology
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• v.44 no.2
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• pp.107-114
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• 2017

Implementation of crop improvement programs relies on genetic diversity. To overcome the limited occurrence of natural mutations, researchers and breeders applied diverse methods, ranging from conventional crossing to classical bio-technologies. Earlier generations of knockout and gain-of-function technologies often result in incomplete gene disruption or random insertions of transgenes into plant genomes. The newly developed editing tool, CRISPR/Cas9 system, not only provides a powerful platform to efficiently modify target traits, but also broadens the scope and prospects of genome editing. Customized Cas9/guide RNA (gRNA) systems suitable for efficient genomic modification of mammalian cells or plants have been reported. Following successful demonstration of this technology in mammalian cells, CRISPR/Cas9 was successfully adapted in plants, and accumulating evidence of its feasibility has been reported in model plants and major crops. Recently, a modified version of CRISPR/Cas9 with added novel functions has been developed that enables programmable direct irreversible conversion of a target DNA base. In this review, we summarized the milestone applications of CRISPR/Cas9 in plants with a focus on major crops. We also present the implications of an improved version of this technology in the current plant breeding programs.

• Genomics & Informatics
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• v.12 no.3
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• pp.105-113
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• 2014

A subset of mammalian genes differ functionally between two alleles due to genomic imprinting, and seven such genes (Peg3, Usp29, APeg3, Zfp264, Zim1, Zim2, Zim3) are localized within the 500-kb genomic interval of the human and mouse genomes, constituting the Peg3 imprinted domain. This Peg3 domain shares several features with the other imprinted domains, including an evolutionarily conserved domain structure, along with transcriptional co-regulation through shared cis regulatory elements, as well as functional roles in controlling fetal growth rates and maternal-caring behaviors. The Peg3 domain also displays some unique features, including YY1-mediated regulation of transcription and imprinting; conversion and adaptation of several protein-coding members as ncRNA genes during evolution; and its close connection to human cancers through the potential tumor suppressor functions of Peg3 and Usp29. In this review, we summarize and discuss these features of the Peg3 domain.

• Molecules and Cells
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• v.41 no.6
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• pp.506-514
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• 2018

The transcriptional regulation of genes determines the fate of animal cell differentiation and subsequent organ development. With the recent progress in genome-wide technologies, the genomic landscapes of enhancers have been broadly explored in mammalian genomes, which led to the discovery of novel specific subsets of enhancers, termed super-enhancers. Super-enhancers are large clusters of enhancers covering the long region of regulatory DNA and are densely occupied by transcription factors, active histone marks, and co-activators. Accumulating evidence points to the critical role that super-enhancers play in cell type-specific development and differentiation, as well as in the development of various diseases. Here, I provide a comprehensive description of the optimal approach for identifying functional units of super-enhancers and their unique chromatin features in normal development and in diseases, including cancers. I also review the recent updated knowledge on novel approaches of targeting super-enhancers for the treatment of specific diseases, such as small-molecule inhibitors and potential gene therapy. This review will provide perspectives on using super-enhancers as biomarkers to develop novel disease diagnostic tools and establish new directions in clinical therapeutic strategies.

• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.291-296
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• 2011

The karyotype of the domestic dog is widely accepted as one of the difficult mammalian karyotypes to work. In contrast to many other animals, knowledge about the canine karyotype is quite sparse. The dog has a total of 78 chromosomes; all 76 autosomes are acrocentric in morphology and show only a gradual decrease in length. But appear to be quite small and difficult to identify unambiguously. To purchased standardization of chromosome in Korea native dog, there were analyzed by conventional trypsin/Giemsa staining (GTG-banding techniques), and were compared with 4, 6, 8, 11, 13, 17 chromosome. There were no variations in karyotypes which were analyzed by conventional GTG-banding techniques, but differences were observed in G-banding patterns with Sapsaree, Jindo, Gyeongju DongGyeong dogs, Welshi-Corgi. It is not clear that these disagreements in G-banding patterns between strains of dog were caused by chromosome polymorphism or a difference in interpretation. Comparative analysis of the distribution patterns of conserved segments defined by dog paints in the genomes of the Korea native dogs demonstrates that their differences in the karyotypes of these three species could have resulted from acrocentric banding patterns.

• Molecules and Cells
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• v.22 no.3
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• pp.360-363
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• 2006

Human endogenous retroviruses (HERVs) contribute to various kinds of genomic instability via rearrangement and retrotransposition events. In the present study the formation of a new human-specific solo-LTR belonging to the HERV-H family (AP001667; chromosome 21q21) was detected by a comparative analysis of human chromosome 21 and chimpanzee chromosome 22. The solo-LTR was formed as a result of an equal homologous recombination excision event. Several evolutionary processes have occurred at this locus during primate evolution, indicating that mammalian-wide interspersed repeat (MIR) and full-length HERV-H elements integrated into hominoid genomes after the divergence of Old World monkeys and hominoids, and that the solo-LTR element was created by recombination excision of the HERV-H only in the human genome.

• Molecules and Cells
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• v.40 no.12
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• pp.954-965
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• 2017

Mammalian genomes are well established, and highly conserved regions within odorant receptors that are unique from other G-protein coupled receptors have been identified. Numerous functional studies have focused on specific conserved amino acids motifs; however, not all conserved motifs have been sufficiently characterized. Here, we identified a highly conserved 18 amino acid sequence motif within transmembrane domain seven (CAS-TM7) which was identified by aligning odorant receptor sequences. Next, we investigated the expression pattern and distribution of this conserved amino acid motif among a broad range of odorant receptors. To examine the localization of odorant receptor proteins, we used a sequence-specific peptide antibody against CAS-TM7 which is specific to odorant receptors across species. The specificity of this peptide antibody in recognizing odorant receptors has been confirmed in a heterologous in vitro system and a rat-based in vivo system. The CAS-TM7 odorant receptors localized with distinct patterns at each region of the olfactory epithelium; septum, endoturbinate and ectoturbinate. To our great interests, we found that the CAS-TM7 odorant receptors are primarily localized to the dorsal region of the olfactory bulb, coinciding with olfactory epithelium-based patterns. Also, these odorant receptors were ectopically expressed in the various non-olfactory tissues in an evolutionary constrained manner between human and rats. This study has characterized the expression patterns of odorant receptors containing particular amino acid motif in transmembrane domain 7, and which led to an intriguing possibility that the conserved motif of odorant receptors can play critical roles in other physiological functions as well as olfaction.

• Journal of Life Science
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• v.32 no.12
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• pp.956-961
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• 2022

Plant Chloroplast have several advantages as an expression platform of biopharmaceuticals over conventional expression platforms such as mammalian cells, yeast and bacteria. First, plants do not serve as a host for mammalian infectious virus and have endotoxin like bacteria which can cause anaphylactic shock. In addition, high copy number of chloroplast genome allows for chloroplast transformants to reach the high level of expression of heterologous genes. Moreover, the integration of transgenes into specific region of chloroplast genomes makes chloroplast transformants unaffected by positional effect which can be frequently observed from nuclear transformants, resulting in loss of transgene expressions. Antimicrobial peptides (AMPs) are a kind of innate immunity which is found from bacteria to humans. Unlike conventional antibiotics, very less dosage of AMPs can have catastrophic effect on bacterial survival. Further, the repeated use of AMPs does not trigger the development of bacterial resistance. Moricin, one of the AMPs, was isolated from Bombyx mori, a silkworm moth. The C-terminal of moricin consists largely of basic amino acids, and the N-terminal has an α-helix structure. Moricin was chosen and expressed in a SUMO/SUMOase without leaving any unwanted amino acids which could potentially affect the anti-bacterial activity of the moricin. The transformation vector used in this study has already been created in this lab for the expression in both prokaryotic systems such as E. coli and chloroplast. The expressed moricin was purified using Ni columns and SUMOase, and the antibacterial activity of the purified moricin was confirmed using an agar diffusion assay.