• 대한의생명과학회지
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• 제11권4호
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• pp.465-471
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• 2005

Ofloxacin has antimycobacterial activity that possibly contributes a pivotal role in the second-line drug regimens that are used for the treatment of multidrug-resistant tuberculosis. However, in some communities, the resistance rate of Mycobacterium tuberculosis to this agent is surging. Therefore, a rapid and accurate method that can be used to determine the resistance of M tuberculosis to the ofloxacin can be very useful for effective treatment of the patients. As an effort to develop such a method, this study was set up to reveal general types of mutations that are related to ofloxacin resistance of M tuberculosis. From previous studies, it has been well known that ofloxacin resistance is associated with mutations in a gene encoding the gyrase A subunit protein. In this study, we obtained 43 ofloxacin-resistant and 50 ofloxacin-susceptible M tuberculosis clinical isolates from Masan National TB Hospital, and sequences of DNA fragment of 320 bp, region of gyrA corresponding to the ofloxacin resistance-determining region were analyzed. In brief, the results showed that a total of seven mutation types were found at gyrA. Theses mutations were all clustered within nucleotides 2574 to 2586 of the gyrA gene (codons 88 to 94). Codon 94 was the most frequently substituted site. Twenty-four of the 43 isolates had mutations at this position resulting in a total of five different types of amino acid changes $(Asp{\to}Ala,\;Asp{\to}Gly,\;Asp{\to}His,\;Asp{\to}Tyr,\;and\;Asp{\to}Asn)$. Five isolates contained a mutation at codon 90 resulting $Ala{\to}Val$ change. Four isolates had mutations at codon 91 causing a $Ser{\to}Pro$ change at this site. Two isolates contained a mutation at codon 88 and each of them resulted in different types of amino acid changes $(Gly{\to}Cys,\;Gly{\to}Ala)$. On the other hand, polymorphic site at codon 95 was found in both ofloxacin-resistant and ofloxacin-susceptible isolates. From these results, we concluded that the rate of mutations present in gyrA among ofloxacin-resistant M. tuberculosis in Korea is similar to the general rates of mutations found throughout the world. Subsequently, an oligonucleotide probe was designed based on the results of sequence analysis and was used to develop a dot blot hybridization assay system to determine ofloxacin-resistance of M tuberculosis. To evaluate this probe, dot-blot hybridization was carried out using other 57 clinical isolates, and the results showed that the dot-blot hybridization assay is good for detecting sequence alterations atgyrA gene.

• Journal of Microbiology
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• 제44권1호
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• pp.54-63
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• 2006

Ferritin is a major eukaryotic protein and in humans is the protein of iron storage. A partial gene fragment of ferritin (255 bp) taken from the total RNA of Periserrula leucophryna, was amplified by RT-PCR using oligonucleotide primers designed from the conserved metal binding domain of eukaryotic ferritin and confirmed by DNA sequencing. Using the $^{32}P-labeled$ partial ferritin cDNA fragment, 28 different clones were obtained by the screening of the P. leucophryna cDNA library prepared in the Uni-ZAP XR vector, sequenced and characterized. The longest clone was named the PLF (Periserrula leucophryna ferritin) gene and the nucleotide and amino acid sequences of this novel gene were deposited in the GenBank databases with accession numbers DQ207752 and ABA55730, respectively. The entire cDNA of PLF clone was 1109 bp (CDS: 129-653), including a coding nucleotide sequence of 525 bp, a 5' -untranslated region of 128 bp, and a 3'-noncoding region of 456 bp. The 5'-UTR contains a putative iron responsive element (IRE) sequence. Ferritin has an open reading frame encoding a polypeptide of 174 amino acids including a hydrophobic signal peptide of 17 amino acids. The predicted molecular weights of the immature and mature ferritin were calculated to be 20.3 kDa and 18.2 kDa, respectively. The region encoding the mature ferritin was subcloned into the pT7-7 expression vector after PCR amplification using the designed primers and included the initiation and termination codons; the recombinant clones were expressed in E. coli BL21(DE3) or E. coli BL21(DE3)pLysE. SDS-PAGE and western blot analysis showed that a ferritin of approximately 18 kDa (mature form) was produced and that by iron staining in native PAGE, it is likely that the recombinant ferritin is correctly folded and assembled into a homopolymer composed of a single subunit.

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.13-25
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• 1999

P. endodontalis which was known to be associated with the infected root canals and periapical lesions is very difficult to detect by culture methods or traditional methods. Detection of bacteria using polymerase chain reaction(PCR) for 16S ribosomal DNA(rDNA) is fast, simple, and accurate with relatively small amount of target cells. 16S rDNA consist of conserved regions those are same to all species, and variable regions which represent species specificity. The 16S rDNA sequences of P. endodontalis and P. gingivalis were aligned and two highly variable regions were selected as a pair of species specific oligonucleotide primers for P. endodontalis. And then the pair of primers for PCR amplification was synthesized to identify P. endodontalis. The sequences of the species specific primers for the 16S rDNA of P. endodontalis were as follows ; sense primer[endo1]: 5'-CTATATTCTTCTTTCTCCGCATGGAGGAGG-3' antisense primer[endo2]: 5'-GCATACCTTCGGTCTCCTCTAGCATAT-3' In this study, for the identification of P. endodontalis without culture from the mixed clinical samples, PCR was done with species specific primers for the 16S rDNA sequences of P. endodontalis. The results were as follows : 1. The species specificity of the primers for the 16S rDNA of P. endodntalis was determined by the PCR methods. About 490bp amplicon which was specific only for P. endodntalis was produced with P. endodontalis. No amplicon was produced by PCR with other strains similar to P. endodontalis. 2. The synthesized species specific primers reacted with conventionally identified P. endodontalis which we have in conservative dentistry laboratory. 3. The identification of P. endodontalis using PCR technique with samples collected from infected root canals or periapical lesions was more sensitive than that of culture methods. 4. Seven samples revealed including P. endodontalis by PCR technique. Five of them were related with pains, two of them with sinus tract, three of them with foul odor, and three of them with purulent drainage. P. endodontalis was shown to have great relation with pains.

• 한국약용작물학회지
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• 제10권3호
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• pp.194-199
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• 2002

한국과 중국 동북부 지역에서 수집한 16종의 더덕으로부터 genomic DNA를 추출한 후, Bioneer사로부터 구입한 random primer(10-mer)를 이용하여 PCR을 수행하였다. 총 49종의 primer를 스크린 한 결과 재현성이 있으면서 polymorphism을 보이는 20개의 primer를 선발하였다. 선발한 primer로부터 PCR에 의해 증폭된 DNA의 크기는 125 bp에서 2.0 kb 내외였으며, 총 148개의 band가 관찰되어 평균 band 수는 7.4개였다. 이들 중에서 polymorphism을 보이는 band의 수는 73개이었으며 (49.3%), polymorphism은 각 primer별로 $1{\sim}9$개로써 다양하였다. 16개 수집종의 유사계수 범위는 0.682에서 0.959로써 유전적 유연정도는 크지 않았다. UPGMA 분석에 의한 수집종들의 유연관계를 dendrogram으로 나타낸 바, 수집종들간의 유전적 거리는 $0.133{\sim}0.400$이었으며, 국내 수집종과 중국 수집종간에는 확실하게 두 그룹으로 분류되었고, 유전적 거리는 약 0.281이었으며, 이들은 모두 지역적인 차이를 보였다. 한편, 중국의 '통화현(通化縣)'과 '류하현(柳河縣)' 수집종이 다른 지역의 수집종보다 유전적 거리가 가장 크게 나타났다.

• 미생물학회지
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• 제28권2호
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• pp.91-97
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• 1990

생체내의 유해산소를 제거하는 superoxide dismutase (superoxide : superoxide oxidoreductase E.C.1.15.1.1) 중 세포질내에서 그 활성을 지니는 인체의 세포질 superoxide dismuta~ie (SODl) 유전자를 사람의 간 cDNA library로부터 동위원소로 표지된 oligonucleotide probe를 이용, in situ plaque hybridization 방법으로 선별 분리하여 내장균 벡터로 클로닝하였다. 이 클론은 SOD1 유전자의 5"L"TR과 3’UTR을 포함한 1.6 kb 정도의 cDNA였다 SOD1 구조유전자만을 선택적으로 분리하기 위해서 ATG를 포함하는 sense strand primer와 3’UTR 부위의 antisense strand primer를 이용하여 중합효소연쇄반응(Polymerase Chain Reaction) 방법을 써서 SOD1 구조유전자 부위만을 선택적으로 증폭시켰다. Taq DNA polymerase에 의해 증폭된 DNA를 벡터 pUCl9의 multiple cloning site (MCS) 내의 Hinc II 위치에 넣였으며 이 insert DNA를 M13 mp19으로 옮겨 dideoxy chain termination 방법으로 sequenase를 사용하여 염기서열을 결정하였다. 클론닝된 cDNA는 153개의 아미노산을 포함하고 있는 하나의 open reading frame (ORF)을 가셨다. 중합효소연쇄반응에 의해 이때 증폭된 SOD1 구조유전자를 $\lambda P_{L}$ 프로모터를 포함하고 있는 발현 벡터 pUPL에 옮긴 후 대장균에서 대량으로 발현시켰다. 이때 발현된 단백질 SOD1은 고유의 효소활성을 가지고 있었다.

• Applied Biological Chemistry
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• 제37권1호
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• pp.56-63
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• 1994

오이모자이크 바이러스(CMV)의 외피단백질 유전자의 일정한 염기서열을 보유하는 부분과 CMV RNA에 대항한 헤머헤드(hammerhead) 구조의 ribozyme을 만드는 올리고뉴클 레오타이드(oligonucleotide, nt)를 DNA 합성기를 이용하여 제조하였다. 올리고뉴클레오타이드의 양쪽가닥을 서로 합친 후 제한효소 BamHl과 SacI으로 처리하여 플라스미드 pBS SK(+)에 삽입하였고 CMV 기질과 ribozyme 클론의 염기서열을 결정하여 확인하였다. 기질과 ribozyme 클론 $1\;{\mu}g$ BssHII이나 SspI으로 처리한후 T7 RNA 합성효소를 이용하여 튜브내에서 전사반응을 실시하였다. 제한효소 BssHII를 처리한 경우 만들어진 기질 RNA의 크기는 176 nt 였는데 50 nt의 CMV RNA 염기, 6 nt의 Xbal 제한효소 염기, 120 nt의 벡터에서 비롯된 염기를 포함한다. Ribozyme RNA의 크기는 164 nt인데 38 nt의 ribozyme 염기부분과 그외는 기질의 것과 같은 염기를 포함한다. CMV 기질 RNA는 ribozyme RNA에 의하여 특이적으로 절단되어 96 nt와 80 nt 두개의 조각을 만들었다. 이러한 특이적 절반은$37^{\circ}C$ 보다 $55^{\circ}C$에서 더 빠르게 일어났다. SspI으로 처리한 경우 만들어진 기질 RNA(2234 nt)도 역시 위치 ribozyme에 의해 두조각으로 절반되었으며 SspI 처리 후 만들어진 ribozyme RNA(2222 nt)에 의해서 특이적으로 절단되었다.

• Applied Biological Chemistry
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• 제45권4호
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• pp.185-189
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• 2002

우리나라의 유전자변형농산물 의무 표시제가 시행됨에 따라 수입 유전자변형농산물 중 유전자변형 콩의 혼입유무를 판별할 수 있는 검정기술 개발이 요구되고 있다. 근사미(glyphosate)제초제에 저항성을 나타내는 토양미생물인 Agrobacterium CP4 유래의 5-enolpyruvyl shikimate-3-phosphate synthase(EPSPS) 유전자의 도입여부를 PCR로 진단할 수 있는 특이프라이머를 제작하여 제초제저항성 콩(Roundup Ready Soybean, RRS)을 검정할 수 있는 PCR조건을 확립하였으며 콩의 내재유전자인 lectin유전자와 RRS특이 프라이머를 이용하여 duplex PCR에 의한 제초제저항성 콩의 검정법을 확립하였다. 또한 수입 콩 및 콩나물에 대하여 근사미 제초제 처리로 저항성 개체를 판별하는 생물검정법도 확립하여 저항성 개체의 잎에서 분리한 genomic DNA에 대하여 EPSPS특이 프라이머를 이용하여 분석한 결과 RRS특이적인 PCR밴드를 확인하였다. 또한 수입 콩의 백립중과 종실의 제색을 고려할 때 단일품종이 아닌 여러 품종이 혼합되어 있음을 확인하였다.

• Clinical and Experimental Reproductive Medicine
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• 제21권1호
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• pp.121-130
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• 1994

Expression of gonadotropin releasing hormone(GnRH) has been described in the rat ovary. It remains, however, unkown whether GnRH is synthesized as a prohormone. Therefore, this study was performed to verify the expression of pro-GnRH by in situ hybridization and further to investigate the effect of gonadotropin on GnRH or GnRH mRNA in rat ovary by immunohistochemical and in situ hybridization techniques. Adult female Sprague-Dawely rats were used and the estrous cycle was synchronized by intraperitoneal injection of pregnant mare's serum gonadotropin(PMSG). Ovaries were fixed with 4% paraformaldehyde and embedded with G.C.T. compound and cut by cryostat. For immunohistochemistry, avidin-biotin peroxidase complex(ABS) method was employed and for in situ hybridization, $^{35}S$-end labeled oligonucleotide was used and followed by autoradiography. By in situ hybridization using GnRH oligomer and GAP(GnRH associated protein) oligomer, GnRH mRNA and GAP mRNA were co-localized in the fullicular cells, luteal cells, interstitial cells and theca cells. GnRH or GnRH mRNA signals in the ovary increased by human chorionic gonadotropin(hCG) injection. At the 3 and 6 hrs after hCG injection, the number of GnRH and GnRH mRNA containing cells increased rapidly and the density of GnRH and GnRH mRHA culminated at 9 hrs after heG injection. With the follicular development, the high expression of GnRH and GnRH mRNA was also observed within the follicles. After ovulation, the density of GnRH or GnRH mRNA decreased in the follicles but increased in the corpus lutea.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1107-1112
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• 2009

The separation of X and Y chromosome-bearing sperm is of use in many aspects of livestock maintenance. In this study, we sought to determine the difference in DNA content between X- and Y-bearing sperm, separate sperm into X- and Y-enriched pools, and assess the efficacy of sorting. Sperm collected from Duroc and miniature pigs were stained with 20.8 $\mu{M}$ Hoechst 33342 and analyzed using a high-speed cell sorter. Measurement of the fluorescence intensity of stained sperm nuclei revealed that the X-bearing sperm of Duroc and miniature pigs respectively contain 2.75% and 2.88% more DNA than Y-bearing sperm. In total, 50.18% of the sperm were assigned to the X-sorted sample and 49.82% was assigned to the Y-sorted sample for Duroc pigs. For miniature pigs, the Xsorted sample represented 50.19% of the population and the Y-sorted represented 49.81% of the population. Duplex PCR was used to evaluate accuracy of sorting. A fast and reliable method for porcine sexing was developed through amplification of the sex-determining region of the Y chromosome gene (SRY). Oligonucleotide primers were designed to amplify the conserved porcine SRY high motility group (HMG) box sequence motif. We found that the primer pair designed in this study was 1.46 times more specific than previously reported primers. Thus, this study shows that the present method can be applied in porcine breeding programs to facilitate manipulation of the sex ratio of offspring and to achieve precise sexing of porcine offspring by amplification of the HMG box of the SRY gene.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권6호
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• pp.581-590
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• 2000

Alterations in the cellular genome affecting the expression or function of genes controlling cell growth and differentiation are considered to be the main cause of cancer. Over 30 oncogenes can be activated by insertional mutagenesis, single point mutations, chromosomal translocations and gene amplification. The ras oncogenes have been detected in $15{\sim}20%$ of human tumors that include some of the most common forms of human neoplasia and are known to acquire their transforming properties by single point mutations in two domains of their coding sequences, most commonly in codons 12 and 61. The ras gene family consists of three functional genes, N-ras, K-ras and H-ras which encode highly similar proteins of 188 or 189 amino acid residues generically known as P21. ras proteins have been shown to bind GTP and GTP, and possess intrinsic GTPase activity. Experimental study was performed to observe the mutational change of the ras gene family and apply the results to the clinical activity. 36 Golden Syrian Hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek (control side) was treated with mineral oil as the same manner of the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were completely dissected by microdissection and DNA from both tissue were isolated by proteinase K/phenol/chloroform extraction. Segments of the K-ras and H-ras gene were amplified by PCR using the oligonucleotide primers corresponding to the homologous region (codon 12 and 61) of the hamster gene, and then confirmational change of ras genes was observed by SSCP and autosequencing analysis. The results were as follows : 1. Malignant lesion could be found in the experimental side from the experimental six weeks. 2. One hamster among six showed point mutation of the H-ras codon 12($G{\rightarrow}A$ transition) at the experimental 10 and 14 weeks. 3. One of six at 6 weeks, two of six at 8 weeks and one of six at 12 weeks revealed the confirmational change of the H-ras codon 61($A{\rightarrow}T$ transversion). 4. The incidence of point mutation of H-ras codon 12 and 61 were 5.5%(2 of 36) and 11%(4 of 36) respectively. 5. Point mutation of the K-ras could not be seen during the whole experimental period. Form the above results, these findings strongly support the concept that H-ras oncogenes may have the influence of the DMBA induced carcinoma of hamster buccal pouch.