• The Korean Journal of Zoology
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• v.37 no.3
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• pp.318-323
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• 1994

The association of replication origins/termini with nuclear matrix during S phase was investigated by DNase digestion of halo structures in synchronized mouse LPI-1 cells. The binding of parental DNA to nuclear matrix was constant throughout S phase. When nuclear matrix was isolated from the cells pulse-labeled with 3H-thvmidine at various stases of S phase, total 3H-labels associated with nuclear matrix were specifically higher at So, Sa and Ss stages than other stases of S phase, suggesting that the newly synthesized DNAs at those stages are not excluded out of nuclear matrix. Similar patterns were obsenred from the pulse-chase experiments, in which cells were pulse-labeled at each stage of S phase and further incubated for 1 hr. These results suggest that the replication origins and termini are fixed at the nuclear matrix, and that the nuclear matrix binding fractions of DNA at 3C-pause may contain a large population of replication origins and termination sites.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.07a
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• pp.69-73
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• 1999

In plants as well as in other multicellular organisms, programmed cell death plays essential roles in the abortion or formation of specific cells and tissues during development to organize the plant [11, 15, 18]. A typical example of developmentally programmed cell death in plants is the death during differentiation of tracheary elements which are components of vessels and tracheids, a water-conducting system. The programming of cell death during tracheary element differentiation has been revealed to be unique to plant cells by using the in vitro Zinnia mesophyll cell culture system. In particular, new biosynthesis of autolysis-related enzymes such as cysteine proteases and nucleases, their accumulation of the vacuole and the programmed collapse of the vacuole are essential to the death of tracheary elements and differ greatly from the process of the apoptotic cell death in animals.

• Journal of Plant Biology
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• v.27 no.1
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• pp.7-13
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• 1984

Activities of corn endosperm adenylate cyclase and phosphodiesterase were found right after germination, and phosphodiesterase activity was shown to increase steadily. Protease activity was also found. Corn peptide fraction purified by using Sephadex G-25 column was shown to enhance corn phosphodiesterase activity buy inhibit bovine phosphodiesterase activity. And the fraction inhibits corn adenylate cyclase activity. Trypsintreated peptide fraction was shown to enhance phosphodiesterase activity 80% compared to that of native peptide fraction. However, in case of DNase phosphodiesterase was shown to be innocuous. According to cumulative results, it is more likely that peptide fraction produced by protease inhibits adenylate cyclase activity and enhance phosphodiesterase, decreasing cAMP level.

• Animal cells and systems
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• v.2 no.2
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• pp.287-295
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• 1998

The Saccharomyces cerevisiae MGMT gene encodes a O6-methylguanine DNA methyltransferase that protects cells from mutation or death by DNA alkylating agents. Using an in vitro transcription system, we analyzed its promoter region to find regulatory elements for transcription initiation. DNase I footprinting and a transcription assay showed that a functional TATA box, 5'-TGATATAGCA-3', is located in the region spanning from -25 to -34. We also found one upstream repressing sequence (URS), -333 to -213, by promoter deletion and competition analysis. Gel mobility shift assays and Southwestern blot analysis using URS region indicate specific complex formations. These results indicate that several cis-acting and trans-acting elements might be involved in the transcriptional regulation of the S. cerevisiae MGMT gene.

• Journal of Life Science
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• v.17 no.11
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• pp.1587-1592
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• 2007

Locus control region (LCR) is a cia-acting element which regulates the transcription of genes in developmental stage and/or tissue-specific pattern. Typically, LCR consists of several DNase I hypersensitive sites (HSs), where the binding motifs for transcriptional activators are present. The binding of activators to the HSs recruits chromatin modifying complexes to the LCR, opening chromatin structure and modifying histones covalently through the locus. LCR forms close physical contact with target gene located at a distance by looping away intervening region. In addition, non-coding RNA is transcribed from LCR toward target genes in continuously acetylated active domain. These structural and functional features of LCR suggest that the LCR plays many roles in chromatin activation and transcriptional regulation.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.38-45
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• 2013

In this study, euryhaline marine microorganism, Bacillus sp. strain EBW4 isolated from polychaete (Perinereis aibuhitensis) of Suncheon Bay was physiologically, biochemically and genetically characterized. Based on 16S rRNA sequence, EBW14 was found to share 98.25% similarity with Bacillus hemicentroti $JSM076093^T$, 97.96% similarity with Bacillus hwajinponensis SW-$72^T$ and 96.28% similarity with B. algicoa $KMM3737^T$, respectively. The temperature range for the growth of strain EBW4 was $4-40^{\circ}C$, NaCl concentration range 0-17% and pH range pH 5-9, revealing that EBW4 was euryhaline bacterium. Major fatty acids in strain EBW4 were composed of anteiso $C_{15:0}$ (48.2%), iso $C_{16:0}$ (12.1%), anteiso $C_{17:0}$ (11.6%) and iso $C_{14:0}$ (9.4%). EBW4 was found to have DNase, amylase, protease and lipase for the degradation of macromolecules such as DNA, carbohydrates, proteins, lipids, etc. The enzyme activities of alkaline phosphatase, esterase (C4), leucine arylamidase and ${\alpha}$-chymotrypsin were also found in strain EBW4. Analysis of the biodegradation ability of EBW4 for organic hydrocarbons under different salinity conditions using synthetic water waste revealed that EBW4 exhibited the ability to degrade organic hydrocarbons very quickly, suggesting strain EBW4 may be a good candidate for the application to various industries.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.105-112
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• 1993

Plesiomonas shigelloides distributed in the aquatic systems was isolated and identified in this study and compared with the c1inica] isolates in view of their physiological characteristics, Biochemica] charactristics of the isolates of P. shigelloides one sample taken from Gupo and two samples taken from Mu]gum, were studied. However, none was isolated in Haeundae, Dadaepo, Kangdong and Nakdong estuary. The isolated bacteria had an optimum growth condition in peptone water of $25~35^{\circ}C$, pH 7.5-8.0 and 1% NaCI concentration. The cell grew most properly on the selective enrichment media which were made from adding inositol to peptone water. DNase was s]owly produced and the results were different from those of other studies. The components of the fatty acid were 3% of 3-hydroxy]ated fatty acid containing $C_{12}~C_{18}$. 0-10% cyclopropane ($C_{17:0}$), 25~30% hexadecanoic acid ($C_{16:0}$), 32~43% hexadecenoic acid ($C_{16:1}$), 1~2% octadecanoic acid ($C_{16:0}$), and 9~14% octadecenoic acid ($C_{18:1}$). Bacterio]ogica] characteristics, susceptibility of antibiotics, and the components of fatty acid of the c1inica] isolates were similar to those of the strains isolated from the aquatic systems. The strains isolated from c1inica] sources degraded lactose more fast than those isolated from the aquatic systems. There existed resistant bacteria to chlorampenicol in the strains from patients, but there were no resistant bacteria in the strains from the aquatic systems. The components of fatty acid of the clinical isolates were 0~2% $C_{17:0 cyclo}$ and 2~3% $C_{18:0}$, but those of the strains from the aquatic systems were 2~10% and 1~2%, respectvely, which showed the quantitative difference between both components.

• Development and Reproduction
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• v.8 no.1
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• pp.27-33
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• 2004

To investigate the mechanism of germ cell death in postnatal stage of mouse, the involvement of apoptotic executioners, caspase-3 and caspase-activated DNase(CAD), and apoptotic initiators, Bax Fas and Fas ligand, in the germ cell death has been studied. Immune-labels of active caspase-3 and CAD were located in TUNEL-positive, apoptotic, oocytes as well as normal oocytes of primary or secondary follicles. CAD immune-labels were also detected in the nucleus of TUNEL-positive oocytes. Most of oocytes showing positive immune-labeling of active caspase-3 or CAD had vacuoles in their cytoplasm, which is the morphological characteristic of oocyte during folliclar atresia. Bax immune-stains were detected in the atretic oocytes which showed the vacuole in their cytoplasm. Positive immune-labels for Fas ligand was localized in TUNEL-positive or atretic oocytes. Presence of immunoreactivity of active caspase-3 and CAD in TUNEL-positive germ cells implicate that active raspase-3 and CAD might play a role in germ cell apoptosis during early development of mouse ovarian follicle. Immunohistochemical localization of Bax and Fas ligand in TUNEL-positive oocytes suggests that these might be the most plausible modulator of oocyte apoptosis.

• Journal of Life Science
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• v.19 no.3
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• pp.305-310
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• 2009

Plasmid pGKV21 contains a 229-nucleotide (nt) single-strand DNA initiation (ssi) signal. Using asymmetric PCR, we prepared a small single-stranded (ss) DNA fragment of the ssi signal and, using the 229-nt ssDNA fragment, determined the requirements of RNA polymerase for priming and DNA-protein interaction. The ssi fragment prepared was able to generate primer RNAs with almost the same efficiency as the $M13{\Delta}lac182/229$ phage DNA. However, the cssi (complementary strand of the ssi signal) fragment could not synthesize primer RNAs. This result suggests that the 229-nt ssi signal functions in a strand specific manner. Gel retardation and DNase I footprinting demonstrated that the synthesized ssi fragment could interact with both E. coli RNA polymerase and SSB protein to synthesize primer RNA. In Escherichia coli [pWVAp], an addition of rifampicin resulted in an accumulation of ssDNA, indicating that the host-encoded RNA polymerase is involved in the conversion of ssDNA to double-stranded plasmid DNA.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.101-111
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• 2001

The present study was conducted to develop an in vitro culture system that would support bovine follicle growth from preantral to antral stage, oocyte maturation, fertilization, and embryonic development. Bovine preantral follicles (150$\pm$1.2 ${\mu}{\textrm}{m}$) surrounded by theca cell were isolated ezymatically and mechanically from ovarian cortical slides in Leibovitz L-l5 medium containing 1 mg/$m\ell$ collagenase and 0.2 mg/$m\ell$ DNase I and cultured for 25 days in the presence of different concentrations of bovine FSH and LH in $\alpha$MEM medium. The survival and growth rates of follicles cultured in the presence of FSH (10~150 ng/$m\ell$) were significantly higher than those of control group (P ＜ 0.001), but no significant differences were observed in survival and growth rates of follicles between the LH treatment groups (1~125 ng/$m\ell$) and the control. The survival (40%) and growth (244 $\pm$ 0.5 $\mu\textrm{g}$) of follicles cultured with FSH (90 ng/$m\ell$) and LH (25 ng/$m\ell$) were higher than those of control (25%, 160 $\pm$1.0 $\mu\textrm{g}$). Finally, 50% percent of healthy antral follicles were obtained, and almost 60% of them has complete meiotic division with 1st polar body (18.1%) and 10.0% have developed to the cleaved embryo and blastocyst stage. These results suggest that bovine preantral follicle with intact theca cell can grow to the antral stage using these culture conditions, and that oocytes from in vitro-matured bovine preantral follicle may acquire meiotic competence and can undergo fertilization and development.