• Radiation Oncology Journal
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• v.23 no.1
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• pp.43-50
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• 2005

Purpose : A number of genes and their products are Induced early or late following exposure of cells to ionizing radiation. These radiation-Induced genes have various effects on irradiated cells and tissues. Suppression subtractive hybridization (SSH) based on PCR was used to Identify the differentially expressed genes by radiation in cervix carcinoma cells. Materials and Methods : Total RNA and poly $(A)^+$ mRNA were Isolated from Irradiated and non-irradiated HeLa cells. Forward- and reverse-subtracted cDNA libraries were constructed using SSH. Eighty-eight clones of each were used to randomly select differentially expressed genes using reverse Northern blotting (dot blot analysis). Northern blotting was used to verify the screened genes. Results : Of the 17t clones, 10 genes in the forward-subtracted library and 9 genes In the reverse-subtracted library were identified as differentially expressed radiation-induced genes by PCR-select differential screening. Three clones from the forward-subtracted library were confirmed by Northern blotting, and showed increased expression in a dose-dependent manner, including a telomerase catalytic subunit and sodium channel-like protein gene, and an ESTs (expressed sequence tags) gene. Conclusion : We Identified differentially expressed radiation-induced genes with low-abundance genes with SSH, but further characterization of theses genes are necessary to clarify the biological functions of them.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.348-354
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• 2004

The expression and antibacterial. activity of recombinant human lactoferrin (hLf) was studied from meth­ylotrophic yeast Pichia pastoris. The gene encoding hLf, isolated from human breast cDNA library, was subcloned into the expression vector, pPIC3.5K under the control of AOX1 promoter. The gene was integrated into the host chromosome and was identified by Southern blotting. The expression of the integrated gene was investigated by RT-PCR, Northern blotting, SDS-PAGE and Western blotting. Discrete band corresponding to hLf was detected from the SDS-PAGE, which was confirmed by Western blotting. The expression was also confirmed by RT-PCR and Northern blotting. The antibacterial activity of the recombinant hLf (rhLf) was investigated using Staphy­lococcus aureus ATCC 6538P and Micrococcus flavus ATCC 10240 as test organisms. The rhLf showed strong antibacterial activities against the bacteria. Furthermore, many Gram-negative animal pathogens such as E.coli ATCC8739, 25922, and Salmonella typhimurium 114 and 115, Pseudomonas fluorescens ID 963 I, P. aeruginosa KCCM 11802, and Gram-positive bacteria Bacillus mesentericus were also inhibited in their growth by the rhLf.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.136-140
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• 1993

The A. nidulans expression vector which contained trpC marker gene from A. nidulans was constructed to produce glucoamy]ase. The recombinant plasmid was introduced into auxotrophic mutant A. nidulans B17. Southern blot analysis of the genomic DNA from transformant showed that pKHG2 DNA had integrated into the A. nidulans chromosomes. Northern analysis of the total RNA from transform ant showed that mRNA of glucoamylase gene was synthesized in induction condition. Specific activity of glucoamylase was increased in transform ants. G]ucoamylase was shown to be active in non-denaturing acrylamide gel.

• Reproductive and Developmental Biology
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• v.33 no.4
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• pp.249-255
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• 2009

The miniature pig is considered to be a better organ donor breed for xenotransplantation than other pig breeds because the size of the organs of the miniature pig is similar to that of humans. In this study, we aimed at identifying differentially expressed genes in the miniature pig ovary during pregnancy. For this, we used the miniature pig ovary model, annealing control primer-based reverse transcription polymerase chain reaction (PCR), quantitative real-time PCR (qRT-PCR), and northern blotting analysis. We identified 13 genes showing differential expression on the based of pregnancy status and validated 8 genes using qRT-PCR. We also sequenced the full-length cDNA of ephrin receptor A4 (EphA4), which had a significant difference in expression level, and validated it by northern blotting. These genes may provide a better understanding of the cellular and molecular mechanisms during pregnancy in miniature pig ovary.

• Journal of Nutrition and Health
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• v.36 no.4
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• pp.376-381
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• 2003

Acyl-CoA synthetase 4 (ACS4) is an arachidonate-preferring enzyme abundant in steroidogenic tissues. We examined ACS4 in rat liver, which contains a variety of pathways that use acyl-CoAs, in order to determine subcellular locations. We demonstrate that ACS4 protein was present most abundantly in the mitochondria and to a much lesser extent in the peroxisomes and microsomes. To determined the dietary effects on the level of ACS4 mRNA, northern blotting was carried out using total RNA from the livers of adult male rats fed various diets. Fasting, high fat diet, and fat-free high sucrose diet increased the hepatic level of ACS4 mRNA approximately 2-fold. Furthermore, the levels of ACS4 mRNA were induced by DEHP[Di- (2-ethylhexyl) phthalate]. These data suggest that ACS4 expression in the liver is regulated with a variety of pathways, including $\beta$-oxidation, hormone, and insulin.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.277-285
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• 2001

Periodontal disease is characterized by inflammation and subsequent loss and/or damage to tooth-supporting tissues such as bone, cementum,and periodontal ligament. Periodontal ligament and cementum are the key tissues in the initial process of regeneration following periodontal disease. Therefore, studies on cementoblasts, which form cementum are emphasized. It is still unclear which cells cementoblast differentiate from. This study was conducted under the hypothesis that PDL fibroblast can differentiate into either cementoblast or osteoblast depending on the conditions of surrounding tissue. Clinically, with excessive traction force of orthodontic appliances or excessive occlusion hypercementosis is observed, and this has been confirmed histologically. Consequently, activation of cementoblast can be expected in rats when mechanical stimuli are given to PDL fibroblast. Therefore, the purpose of this article is to prove that PDL fibroblast differentiates into cementoblast in rats under mechanical stimuli using histologic and molecular methods. In this study, twenty rats were given hard diet. Ten of them were sacrificed after 1 week, and the others were sacrificed after two weeks. Slides were made from tooth specimen, and they were studied under the microscope. In addition, PDL fibroblast and cementum from the extracted teeth were analyzed with Northern blotting. In histologic examination, as time passed, PDL fibroblast migrated to the dentin side, differentiated into cementoblast, and formed new cementum. In Northern blotting, it was found that mRNA expression of cementoblast-specific proteins such as BSP, OC, OPN, and type I collagen were more prominent in rats sacrificed after 2 weeks of hard-diet than rats sacrificed after 1 week. From these findings we can conclude that PDL fibroblast can differentiate into cementoblast under mechanical stimuli. We think that 'Rat Models' used in this study will be beneficial to future studies regarding cementoblast.

• 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.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.109-116
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• 1999

Purpose: Insulin-like growth factor(IGF)-I and -II are peptide growth factor whose activity is modulated by interaction with the family of six IGF-binding proteins(IGFBPs). IGF-I is detected in rat kidney and has metabolic and growth effects. This study was designed to examine temporal expression of IGFBPs in kidney during renal development and postischemic regeneration in rat. Method: The expression of IGFBPs in kidney during renal development from 15th day of gestation to adult life by using Northern blot analysis. We also examined the renal IGF-IGFBP axis in uremic rat by using Northern blot and immunohistochemistry. Results: The mRNA of IGFBP-1 and -3 were not or barely detected in fetal stages. However, the mRNA level of IGFBP-1 and -3 were increased gradually from day 7 after birth to adult. In contrast, the mRNA of IGFBP-2 and -5 were highly expressed in fetal stages and maintained almost same levels until day 7 (IGFBP-2) or day 30 (IGFBP-5) after birth, then their levels decreased markedly. The mRNA of IGFBP-4 were expressed moderately in fetal kidney and increased gradually after birth. Interestingly, the mRNA of IGFBP-1 and-4 were induced up to 3-5 fold during maximum regeneration period and were recovered to normal levels after acute ischemic injury. In contrast, the mRNA level of IGFBP-3 and-IGFBPrP-1 were decreased slightly at 1 day after ischemic injury, then recovered to normal level during maximum regeneration period. Conclusion: There were differential expressions of IGFBPs in kidney that can modulate IGF action on developing, differentiating, maintaining, and regenerating renal structure and function.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.373-379
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• 1993

The heat shock protein (HSP) genes are expressed at various stages of the Drosophila life cycle even under non-heat-shock conditions. In the present study, developmental changes of HSP23 gene expression and the role of 20-hydroxyecdysone (2OHE) on the HSP23 gene expression were investigated in Drosophila melanogaster. The Northern blot and Western blot analyses showed that HSP23 gene expression occurred at the early third instar larval stage, reached the highest with a sharp peak in the white prepupa, and then decreased throughout the pupal period. When the HSP23 gene expression was compared with the secretion of 20HE, there is a slmiladty between 20HE synthesis and HSP23 gene expression during the third instar larval-prepupal period. It appears that 2OHE regulates expression of HSP23 gene at larva-pupa molting period, and that, 2OHE is also involved in the control the metamorphosis in some part through the HSP23.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.141-142
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• 2005