• The Korean Journal of Zoology
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• v.37 no.2
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• pp.232-239
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• 1994

RecA protein plans a central role in homologous recombination and DNA repair in Escherichia cofi (E. colD. The function 8nd structure of this protein are universal in prokarvotes and also conserved in eukaryotes such as yeast. The RecA-like protein with 74 lInDa in size has already been identified and purified from a fission yeast Schizosaccharomyces pombe (5. pommel (Lee, 19911. From this study it was revealed that the RecA-like protein of 5. pombe was highly inducible to various DNA damaging agents and inhibitors of nucleotide pool svnthesizins enzymes. The cellular level of the 5. pombe RecA-like protein wi,u markedly increased, upto 5- to 10-fold, by treatment with various DNA-damains agents including ultraviolet (UV) light, methyl methanesulfonate WS),4-nitroquinoline-1-oxide (4-NQO), and mitomycin-C (MMC), similar to E. cofi RecA protein. Interestingly, the protein level was also increased by inhibitors of nucleotide pool forming enzlwnes such as methotrexate (MTX) and hvdroxvurea (HU). The most effective doses for the inducibility of 4-NQO, MMS, W, MMC, MTX, and HU were 0.2 Ug/ml, 30 mM, 200 J/ma, 0.4 $\mus/ml,$ 1 Ug/ml, and 100 mM, respectively. The range of effective duration time for the inducibilitv of RecA-like protein was from 270 to 450 mins. These results suggest that the 5. pombe RecA-like protein also platys an imortant role in cellular responses to DNA damage as in E. coli system.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.281-287
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• 2021

Bioinformatics is formed with a blend of biology and informatics technologies and it employs the statistical methods and approaches for attending the concerning issues in the domains of nutrition, medical research and towards reviewing the living environment. The ceaseless growth of DNA sequencing technologies has resulted in the production of voluminous genomic data especially the DNA sequences thus calling out for increased storage and bandwidth. As of now, the bioinformatics confronts the major hurdle of management, interpretation and accurately preserving of this hefty information. Compression tends to be a beacon of hope towards resolving the aforementioned issues. Keeping the storage efficiently, a methodology has been recommended which for attending the same. In addition, there is introduction of a competent algorithm that aids in exact matching of small pattern. The DNA representation sequence is then implemented subsequently for determining 2 bases to 6 bases matching with the remaining input sequence. This process involves transforming of DNA sequence into an ASCII symbols in the first level and compress by using LZ77 compression method in the second level and after that form the grid variables with size 3 to hold the 100 characters. In the third level of compression, the compressed output is in the grid variables. Hence, the proposed algorithm S_Pattern DNA gives an average better compression ratio of 93% when compared to the existing compression algorithms for the datasets from the UCI repository.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6535-6539
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• 2015

This study was designed to assess, whether a new chemotherapeutic microtubule inhibitor, Epothilone B (EpoB, Patupilone), can induce DNA damage in normal ovarian cells (MM14.Ov), and to evaluate if such damage could be repaired. The changes were compared with the effect of paclitaxel (PTX) commonly employed in the clinic. The alkaline comet assay technique and TUNEL assay were used. The kinetics of DNA damage formation and the level of apoptotic cells were determined after treatment with IC50 concentrations of EpoB and PTX. It was observed that PTX generated significantly higher apoptotic and genotoxic changes than EpoB. The peak was observed after 48 h of treatment when the DNA damage had a maximal level. The DNA damage induced by both tested drugs was almost completely repaired. As EpoB in normal cells causes less damage to DNA it might be a promising anticancer drug with potential for the treatment of ovarian tumors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.109-110
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• 2007

Pyrrole and DNA can be used for synthesis of conducting nanowires. Protonated pyrrole and negatively charged DNA are absorbed by electrostatic interaction. The level of absorbance is related to pH of pyrrole. Therefore, DNA immobilized and aligned on the 3-aminopropyltrimethoxysi1ane (APTES) modified Si surface. Positive pyrrole monomers was deposited on aligned DNA for the synthesis of nanowire in various pH condition. And polypyrrole nanowires were synthesized by polimerization with ammonium persulfate (APS). These polypyrrole nanowires were measured by AFM, and then we found optimal pH level for the synthesis of nanowires.

• Journal of Nutrition and Health
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• v.32 no.5
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• pp.526-532
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• 1999

The aim of this study was to observe whether the dietary supplementation of docosahexaenoic acid(DHA). In growing rats requires extra supplementation of arachidonic acid(AA) for brain development. Sprague-Dawley rats were divided into three groups, each fed a different diet. In the FO group, dams were fed a DHA-rich FO diet during pregnancy and lactation and pups were fed the same diet until 10 weeks old. In the AO group dams and pups were similarly fed a FO diet after weaning. DHA and AA were most effetively deposited in the developing brain during pregnancy and lactation in rats. However, FO-W pups showed significantly lower level of DHA at 0-3 weeks compared with the FO and AO groups and than slowly increased DHA levels to about 87% of other groups at 10 weeks with the introduction of the FO diet after weaning. The total amount of DNA in whole brain rapidly reached a maximum level at 3 weeks and then was sustained at a constant level after 5 weeks of age. The DNA content was positively correlated with DHA level but not with AA level in the developing brain. DNA content was significantly lower in the FO-W group compared to the FO and AO group at 3 weeks of age. However, the DNA content of brain in FO-W pups increased to 80% of the FO group level at 10 weeks after feeding the FO diet after weaning. The relative percentage of AA in brain lipids was significantly reduced in the early stage of brain development when only DHA was supplemented. However, DHA supplementation had no significant effect on the incorporation of AA when the approximately 35% of LA in the FO diet was substituted by preformed AA. These results suggest that large quantities of DHA could interfere with the normal conversion of LA to AA if LA is not supplemented enough together with DHA. Therefore, high DHA supplementation may require preformed AA in the diet even though AA has no significant correlation with the DNA content in brain. DHA supplementation after weaning also improved the incorporation of DHA into brain and content of DNA even though brain development was almost completed, suggesting that a low level of DHA supplementation without AA addition might be necessary to improve brain development during infancy as well as during pregnancy and lactation.

• Molecules and Cells
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• v.41 no.2
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• pp.127-133
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• 2018

Chromatin remodeling factors are involved in many cellular processes such as transcription, replication, and DNA damage response by regulating chromatin structure. As one of chromatin remodeling factors, remodeling and spacing factor 1 (RSF1) is recruited at double strand break (DSB) sites and regulates ataxia telangiectasia mutated (ATM) -dependent checkpoint pathway upon DNA damage for the efficient repair. RSF1 is overexpressed in a variety of cancers, but regulation of RSF1 levels remains largely unknown. Here, we showed that protein levels of RSF1 chromatin remodeler are temporally upregulated in response to different DNA damage agents without changing the RSF1 mRNA level. In the absence of SNF2h, a binding partner of RSF1, the RSF1 protein level was significantly diminished. Intriguingly, the level of RSF1-3SA mutant lacking ATM-mediated phosphorylation sites significantly increased, and upregulation of RSF1 levels under DNA damage was not observed in cells overexpressing ATM kinase. Furthermore, failure in the regulation of RSF1 level caused a significant reduction in DNA repair, whereas reconstitution of RSF1, but not of RSF1-3SA mutants, restored DSB repair. Our findings reveal that temporal regulation of RSF1 levels at its post-translational modification by SNF2h and ATM is essential for efficient DNA repair.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.5
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• pp.551-556
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• 2004

According to revealing the DNA sequence of human and living things, it increases that a demand on a new computational processing method which utilizes DNA sequence information. In this paper we propose a classification algorithm based on negative selection of the immune system to classify DNA patterns. Negative selection is the process to determine an antigenic receptor that recognize antigens, nonself cells. The immune cells use this antigen receptor to judge whether a self or not. If one composes n group of antigenic receptor for n different patterns, they can classify into n patterns. In this paper we propose a pattern classification algorithm based on negative selection in nucleotide base level and amino acid level.

• YAKHAK HOEJI
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• v.33 no.5
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• pp.300-307
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• 1989

Expression of transferrin gene in various organs of rat was studied using rat transferrin cDNA. The hybridization method of $[^{35}S]-labeled$ transferrin cDNA with transferrin mRNA in cytoplasmic preparations was used to measure the level of transferrin mRNA. The rat from 15-day old fetus to 21-day old postnatal were employed as an animal model. In the liver, the level of transferrin mRNA increased with increasing age. However, the level of transferrin mRNA in brain was significantly lower than that in liver and the level did not increase with age.

• Journal of Yeungnam Medical Science
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• v.19 no.1
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• pp.1-10
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• 2002

With the establishment of rapid sequence analysis of 16S rRNA and the recognition of its potential to determine the phylogenetic position of any prokaryotic organism, the role of 16S rRNA similarities in the present species definition in bacteriology need to be clarified. Comparative studies clearly reveal the limitations of the sequence analysis of this conserved gene and gene product in the determination of relationship at the pathogenic strain level for which DNA-DNA reassociation experiments still constitute the superior method. Since today the primary structure of 16S rRNA is easier to determine than hybridization between DNA strands, the strength of the sequence analysis is to recognize the level at which DNA pairing studies need to be performed, which certainly applies to similarities of 97% and higher.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.1
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• pp.8-13
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• 2019

Objective: Density gradient centrifugation (DGC) is frequently used to isolate high-motility fractions of spermatozoa. We compared the efficacy of four DGC media in terms of the percentage of morphologically normal spermatozoa, DNA fragmentation level, and hyaluronic acid (HA) binding ability. Methods: Thirty men with a total motile spermatozoa count > 80 million participated. Semen samples were divided into four aliquots, which were processed using PureSperm, PureCeption, Sidney, and SpermGrad media, respectively. The DNA fragmentation level was measured using the Halosperm assay kit and HA binding ability was measured using the HBA assay kit. Results: The mean percentage of morphologically normal spermatozoa was significantly enhanced after DGC using all four media (10.3%, 9.9%, 9.8%, and 10.7%, respectively; p< 0.05 for each when compared with 6.9% in raw semen). The DNA fragmentation level was significantly reduced after DGC using PureSperm, PureCeption, and SpermGrad media (6.0%, 6.5%, and 4.9%, respectively; p< 0.05 for each when compared with 11.2% in raw semen), but not after DGC using Sidney media (8.5%, p> 0.05). HA binding ability did not change after DGC using any of the four media. Conclusion: The four media were equally effective for obtaining a sperm fraction with highly motile, morphologically normal sperm. PureSperm, PureCeption, and SpermGrad media were equally effective for acquiring a sperm fraction with less DNA fragmentation.