• Clinical and Experimental Reproductive Medicine
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• v.33 no.4
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• pp.253-263
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• 2006

Objective: Identification of the regulatory mechanism for arrest and initiation of primordial follicular growth is crucial for female fertility. Previously, we found 15 expressed sequence tags (ESTs) that were specifically abundant in the day-S-subtracted cDNA library and that the B357 clone was novel. The present study was conducted to obtain the whole sequence of the novel gene including B357 and to characterize its mRNA and protein expression in mouse ovary and testis. Methods: The extended sequence of the 2,965-bp cDNA fragment for the clone B357 was named ${\underline{5}}-{\underline{d}}ay-{\underline{o}}vary-{\underline{s}}pecific\;gene-{\underline{1}}$ (5DOS1) and submitted to GenBank (accession number ${\underline{AY751521}}$). Expression of 5DOS1 was characterized in both female and male gonads at various developmental stages by Northern blotting, real-time RT-PCR, in situ hybridization, Western blotting, and immunohistochemistry. Results: The 5DOS1 transcript was highly expressed in the adult testis, brain, and muscle as compared to the other tissues. In the ovary, the 5DOS1 transcript was detected in all oocytes from primordial to antral follicles, and highly expressed at day 5 after birth and decreased thereafter. In contrast, expression of 5DOS1 showed a gradual increase during testicular development and its expression was limited to various stages of male germ cells except spermatogonia. Conclusions: This is the first report on the expression and characterization of the 5DOS1 gene in the mouse gonads. Further functional analysis of the 5DOS1 protein will be required to predict its role in gametogenesis.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.52-58
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• 2005

In Korea, little attention has been paid to microbial perchloroethylene (PCE) and/or trichloroethylene (TCE) dechlorination activity and identification of microorganisms involved in PCE reductive dechlorination at a PCE-contaminated aquifer. We performed microcosm tests using the groundwater samples from 4 different contaminated sites (i.e. Changwon A, Changwon B, Bucheon and Yangsan) to assess PCE reductive dechlorination activity. We also adapted molecular techniques to screen what types of known reductive dechlorinators are present at the PCE-contaminated aquifers. In the Changwon A and Changwon B active microcosms where potential electron donors such as sodium propionate, sodium lactate, sodium butyrate, and sodium fumarate, were added, ethylene, an end-product of complete reductive dechlorination of PCE, was detected after a period of 90 days of incubation. In the Bucheon and Yangsan active microcosms, cis-1,2-dichloroethylene (c-DCE) was accumulated without the production of vinyl chloride (VC) and ethylene. Molecular techniques were used to evaluate the microbial community structures in the Changwon B and Yangsan aquifer. We found two sequence types that were closely related to a known PCE to ethylene dechlorinator, named uncultured bacterium clone DCE47, in the Changwon B site clone library. However, in the Yangsan site clone library, no sequence type was closely related to known PCE dechlorinators reported. It is plausible that microorganisms being capable of completely dechlorinating PCE to ethylene may be present in the Changwon B site aquifer. In this study we find that complete PCE reductive dechlorinators are present at some PCE-contaminated sites in Korea. In an engineering point of view this information makes it feasible to apply a biological reductive dechlorination process for remediating PCE- and/or TCE-contaminated aquifers in Korea.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.127-130
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• 2004

Grapevine leaf roll-associated virus 3 (GLRaV-3) is one of the most important viral diseases of grapevine in the world. In this study, GLRaV-3 Ampelovirus was identi-fied from grapevines in Korea by analyzing viral coat protein size, nucleotide, and amino acid sequences. The molecular weight of viral coat protein from virus-infected in vitro plantlets was determined by western blot using a commercial GLRaV-3 polyclonal antibody. Western blot analysis showed a coat protein of about 43 kDa. RT-PCR product of about 942 bp which encoded the coat protein (CP) gene was amplified with specific primers. When the viruses existed at low titers in the host plant, the dsRNA had very specific template in RT- PCR amplification of fruit tree viruses. Especially, small-scale dsRNA extraction method was very reliable and rapid. Sequence analysis revealed that the CP of the GLRaV-3 Ko consisted of 942 bp nucleotide, which encoded 314 amino acid residues. The CP gene of GLRaV-3 Ko had 98.9% nucleotide sequence and 98.7% amino acid sequence identities with earlier reported GLRaV-3. This is the first report on molecular assay of GLRaV-3 Ampelovirus identified from Korea. The GLRaV-3 Ko CP clone would be very useful for breeding of virus resistant grapevines.

• Genomics & Informatics
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• v.4 no.1
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• pp.11-15
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• 2006

The aim of this study is to identify hRad21-binding sites in human chromosome, the core component of cohesin complex that held sister chromatids together. After chromatin immunoprecipitation with an hRad21 antibody, it was cloned the recovered DNA and sequenced 30 independent clones. Among them, 20 clones (67%) contained repetitive elements including short interspersed transposable elements (SINE or Alu elements), long terminal repeat (LTR) and long interspersed transposable elements (LINE), fourteen of these twenty (70%) repeats clones had Alu elements, which could be categorized as the old and the young Alu Subfamily, eleven of the fourteen (73%) Alu elements belonged to the old Alu Subfamily, and only three Alu elements were categorized as young Alu subfamily. There is no CpG island within these selected clones. Association of hRad21 with Alu was confirmed by chromatin immunoprecipitation-PCR using conserved Alu primers. The primers were designed in the flanking region of Alu, and the specific Alu element was shown in the selected clone. From these experiments, it was demonstrated that hRad21 could bind to SINE, LTRs, and LINE as well as Alu.

• Biomedical Science Letters
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• v.23 no.1
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• pp.1-7
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• 2017

It is known that acute myeloid leukemia (AML) is a heterogeneous blood cancer, which is enormously propagated by self-renewing leukemia stem cells (LSCs). The persistence of LSCs after chemotherapy can contribute to minimal residual disease and relapse by LSCs can be evoked promptly. Elucidating special molecules and cellular activity of LSCs is an extremely important to eliminate AML. Despite an increasing understanding of the origin of LSCs by incessant study, AML still remains a notorious disease with high mortality. An exact identification of the LSCs that sustain the proliferation of neoplastic clone is a fundamental issue in AML treatment. CD34+CD38- conventional phenotype is overall regarded as LSCs, but it has a limitation that is still hard to demarcate exactly due to similarity with normal hematopoietic stem cells (HSCs). Not all primary blasts and progenitors have equal function, thus a bona fide marker for identifying LSCs from HSCs is needed in hematologic malignancy, especially in AML. These findings have direct important implications in both in mechanistic study of LSCs as well as in the strategies of more effective therapies. In this review, I briefly summarized current advances in LSCs biology, focusing on membrane markers and a functional behavior of LSCs in AML treatment with monoclonal antibodies. Ultimately, it may be helpful in overviewing the status of LSC research, while expecting the clinic benefits of target therapy by specific inhibition.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.71.2-71
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• 2003

Ralstonia solancearum infects many solanaceous plants, however race 3 infects only potato and tomato weakly. To identify genes responsible for race specificity of R. solanacearum, we mobilized genomic library of LSD2029 (race 3) into LSD341 (race 1) and inoculated 1,000 transconjugants into hot pepper. One transconjugant that did not induce wilt symptom in hot pepper was isolated. We found that a cosmid clone, pRSl, conferred avirulence to LSD341. By deletion and mutational analyses of pRSl, we found the 0.9-kb PstI/Hindlll fragment carries avirulence functions. We sequenced the fragment and identified one possible open reading frame, a rsal gene, possibly encoding 110 amino acids. The rsal was preceded with a plant-inducible promoter (PIP) box, indicating that the gene might be regulated by HrpB. Interestingly, the promoter region of the rsal homolog in the strain GM11000 (race 1) did not have the PIP box. Rsal did not show any significant homologies with proteins in the database, indicating th e protein is different from the previously reported avirulence proteins. When we mutated the rsal gene by marker-exchange in LSD2029, the mutant was less virulent in potato.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.508-513
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• 2002

Human endogenous retroviral long terminal repeats (LTRs) have been found to be coexpressed with sequences of genes located nearby. It has been suggested that the LTR elements have contributed to the structural change or genetic variation of human genome connected to various diseases. The HERV-W family has been identified in the cerebrospinal fluids and brains of individuals with schizophrenia. Using a cDNA library derived from a human brain, the HERV-W LTR elements were examined and five new LTR elements were identified. These elements were examined using a YAC clone panel from the Xq21.3 region linked to psychosis that was replicated on the Y chromosome after the separation of the chimpanzee and human lineages. Fourteen elements of the HERV-W LTR were identified in that region. Those LTR elements showed a high degree of sequence similarity ($91.8-99.5\%$) with previously reported HERV-W LTR. A phylogenetic tree obtained from the neighbor-joining method revealed that new HERV-W LTR elements were closely related to the AXt000960, AF072504, and AF072506 from the GenBank database. The data indicates that several copy numbers of the HERV-W LTR elements exist on the Xq21.3 region and are also expressed in the human brain. These LTR elements need to be further investigated as potential leads to neuropsychiatric diseases.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.835-842
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• 2014

Haloperoxidase (HPO, E.C.1.11.1.7) is a metal-containing enzyme oxidizing halonium species, which can be used in the synthesis of halogenated organic compounds, for instance in the production of antimicrobial agents, cosmetics, etc., in the presence of halides and $H_2O_2$. To isolate and evaluate a novel non-metal HPO using a culture-independent method, a cassette PCR library was constructed from marine seawater in Japan. We first isolated a novel HPO gene from Pseudomonas putida ATCC11172 by PCR for constructing the chimeric HPO library (HPO11172). HPO11172 showed each single open-reading frame of 828 base pairs coding for 276 amino acids, respectively, and showed 87% similarity with P. putida IF-3 sequences. Approximately 600 transformants screened for chimeric genes between P. putida ATCC11173 and HPO central fragments were able to identify 113 active clones. Among them, we finally isolated 20 novel HPO genes. Sequence analyses of the obtained 20 clones showed higher homology genes with P. putida or Sinorhizobium or Streptomyces strains. Although the HPO A9 clone showed the lowest homology with HPO11172, clones in group B, including CS19, showed a relatively higher homology of 80%, with 70% identy. E. coli cells expressing these HPO chimeric genes were able to successfully bioconvert chlorodimedone with KBr or KCl as substrate.

• Animal cells and systems
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• v.13 no.2
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• pp.119-125
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• 2009

Mammalian hibernation is a type of natural adaptation that allows organisms to avoid harsh environment and to increase the possibility of survival. To investigate the molecular link between circadian and hibernating rhythms in the greater tube-nosed bats, Murina leucogaster, we set out to identify circadian genes that are expressed in bats, with specific focus on the PAS domain by using PCR-based screens. We could isolate a eDNA clone, designated as LPAS1, that encodes a protein of 521 amino acid residues. LPAS1 is closely related with CLOCK family with the highest homology to human CLOCK. Based on RT-PCR analyses, LPAS1 transcripts are ubiquitously present in tissues from both summer active and winter dormant periods. Given that LPAS1 is a member of the bHLH-PAS protein superfamily but lacks polyglutamine transactivation domains, it is likely to function as a repressor for endogenous CLOCK to hinder its roles in promoting transcription. Our result will open a new avenue to further examine the functional interconnection between the circadian clock and the circannual clock such as mammalian hibernation.

• International Journal of Oral Biology
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• v.39 no.4
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• pp.215-220
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• 2014

Toothbrushes play an essential role in oral hygiene. However, they can be significant in microbial transmission and can increase the risk of infection, since they can serve as a reservoir for microorganisms in healthy, oral-diseased and medically ill adults. This study was conducted to evaluate toothbrush contamination in six toothbrushes donated from four people. Two participants each supplied two toothbrushes - one used in the bathroom and one used in the workplace. The other two people each donated two toothbrushes used in the workplace. Polymerase chain reaction was used to construct a 16S rRNA clone library. Sequences of cloned DNA were compared with those from the reference organisms provided by GenBank. A total 120 clones, representing 20 clones for each toothbrush, were analyzed. They are composed of six pylum, 46 genera and 79 species. The most dominant species were Streptococcus oralis, Streptococcus parasanguinis and Haemophilus parainfluenzae. Enterobacter and Escherichia were recovered from toothbrushes used domestically. Toothbrushes used in the workplace did not contain Enterobacteria.