• Mycobiology
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• 제49권2호
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• pp.122-132
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• 2021

The reexamination of the fungal genus Botryosphaeria on 12 plant species of 10 families was carried out based on molecular phylogenetic analyses using the regions of translation elongation factor 1-α, β-tubulin, DNA-directed RNA polymerase II subunit, and internal transcribed spacer region of rDNA and morphological characteristics. Japanese isolates were divided into five clades and include Botryosphaeria dothidea, B. qingyuanensis, B. sinensis, and Botryosphaeria spp. Two species, B. qingyuanensis and B. sinensis have been newly added to the Japanese mycoflora, but their host plants are not specified. Botryosphaeria tenuispora isolated from Leucothoe fontanesiana and insect galls on fruits of Aucuba japonica has been proposed as a new species.

• Animal cells and systems
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• 제8권3호
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• pp.231-233
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• 2004

Sequences of cytochrome b gene and control region of mitochondrial DNA from Korean common otters (Lutra lutra lutra L.) were examined to provide the genetic information for the conservation of this subspecies. Two haplotypes and one haplotype were revealed in cytochrome b gene and control region, respectively. The available sequences of European common otter (L. l. lutra) from GenBank were compared together with those of Korean common otter in order to determine the degree of sequence variation between them. In cytochrome b gene sequences, two haplotypes from Korea and two haplotypes of Europe showed differences in 12 of 1,045 sites. The Tamura-Nei nucleotide distances between two European haplotypes was 0.10% and those between two Korean haplotypes was also 0.10%, but those between Korean haplotypes and European ones ranged from 0.96% to 1.16%. In the control region, one Korean haplotype and seven European ones showed differences in seven of 300 sites; the Tamura-Nei distances among seven European haplotypes were 0.34% to 1.01%, but those between Korean haplotype and European ones ranged from 1.01% to 1.69%. Although further molecular and morphological studies with specimens from eastern Asia including Amur region and northeast China are needed, it is possible that the Korean common otter might be closer or identical to the far-eastern Asian common otter, L. l. amurensis Dybowski.

• 한국미생물·생명공학회지
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• 제34권1호
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• pp.23-27
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• 2006

본 연구에서는 국내시장에서 유통되는 육류, 냉동식품, 생우유, 조개류 등과 같은 식품으로부터 L. monocytogenes들을 분리하고 혈청형을 결정하였다. RAPD 결과를 통해서 L. monocytogenes는 Listeria 속의 다른 균주들과 전체 밴드의 수와 크기에서 구별이 되었다. 또한, L. monocytogenes는 2개 그룹으로 구별되었으며, 그룹 I은 L. monocytogenes 1/2b, 4e, 4b, 그룹 II는 L. monocytogenes 1/2a, 1/2c, 3 혈청형 그룹별로 분류되었다. 결론적으로 RAPD 방법과 serotyping은 L. monocytogenes를 분류하는 데에 있어서 기존의 방법의 단점을 보완한 새로운 가능성을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.471-476
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• 2007

Little is known about the origin and genetic diversity of swamp buffaloes in China. To obtain more knowledge on genetics of the water buffalo in China, the complete mitochondrial D-loop sequences of 30 samples from 6 native types were investigated. The results revealed 12 mitochondrial haplotypes with 50 polymorphic sites. Among these polymorphic sites, there were 49 transitions and 1 transversion. The average nucleotide diversity and haplotype diversity estimated from mtDNA D-loop region in 6 Chinese water buffalo types were 0.00684 and 0.798, respectively, showing rather abundant mitochondrial genetic diversity. The Neighbor-Joining (NJ) tree of mtDNA of Chinese water buffaloes was constructed according to the 12 haplotypes. The NJ tree indicated two lineages being designated lineage A and lineage B, in which lineage A was predominant, and lineage B was at low frequency. The new lineage B was first discovered and defined in 6 Chinese water buffalo types. These results showed that two different maternal lineages were involved in the origin of domestic swamp buffaloes in China and the lineage B was probably an introgression from Southeast Asian buffaloes.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.244-252
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• 2007

Escherichia coli has a PhoR-PhoB two-component regulatory system to detect and respond to the changes of environmental phosphate concentration. For the E. coli W3110 strain growing under phosphate-limiting condition, the changes of global gene expression levels were investigated by using DNA microarray analysis. The expression levels of some genes that are involved in phosphate metabolism were increased as phosphate became limited, whereas those of the genes involved in ribosomal protein or amino acid metabolism were decreased, owing to the stationary phase response. The upregulated genes could be divided into temporarily and permanently inducible genes by phosphate starvation. At the peak point showing the highest expression levels of the phoB and phoR genes under phosphate-limiting condition, the phoB- and/or phoR-dependent regulatory mechanisms were investigated in detail by comparing the gene expression levels among the wild-type and phoB and/or phoR mutant strains. Overall, the phoB mutation was epistatic over the phoR mutation. It was found that PhoBR and PhoB were responsible for the upregulation of the phosphonate or glycerol phosphate metabolism and high-affinity phosphate transport system, respectively. These results show the complex regulation by the PhoR-PhoB two-component regulatory system in E. coli.

• Journal of Periodontal and Implant Science
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• 제25권1호
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• pp.153-166
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• 1995

54 clinical isolates of Actinobacillus actinomycetemcomitans showed distinct hybrdization patern(DAN fingerprinting patterns) when the bacterial DNA were hybridized with randomly cloned 4.7 - kb DNA probe. The frequency of the genotypic distribution demonstrated that type C was the most prevalent genotype, the next being D, NT, A, B, and E in the descending order. The most prevalent serotype was serotype c, the next being a, nd, and b in the descending order. It was noted that the one serotype can represent more than two different genotypes and that multiple genotypic variants can also exist in the periodontal pockets within the sam subject.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.352-357
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• 1999

Enterobacter sp. B54 inhibited growth of the fungus Phytophthora capsici on potato dextrose agar (PDA). Three mutants with antifungal activities (denoted M54-47, M54-113, and M54-329) which were lost or increased, through Pl::Tn5 lac mutagenesis, were used to isolate genes responsible for fungal inhibition on PDA. Two clones were selected from the partially EcoR1-digested genomic library of the wild-type strain by probing with genomic flanking sequences of each mutant. We have isolated a 20-kb EcoR1 genomic DNA fragment from this strain that contains genes involved in hyphal growth inhibition of P. capsici on PDA. Subcloning and expression analysis of the above DNA fragment identified a 8-kb region which was necessary for antifungal activities. A 8-kb HindⅢDNA fragment covers three genomic loci inserted by Tn5 lac in each mutant. This suggested that all genes which are related to antifungal activities might be clustered in simple forms of at least 5-8 kb sizes.

• 한국미생물·생명공학회지
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• 제14권2호
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• pp.133-137
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• 1986

원생동물인 Tetrahymena thermophila의 17S-rDNA구조 및 hygromycin 내성 기구에 대한 연구의 일부로서 hygromycin 내성변이주 hmr3의 17S-rDNA를 대장균의 vector pBR 322에 cloning하였다. 우선 rDNA는 hot phenol-cresol 용액으로 추출하여 제한효소 Hind III 처리로서 약 2.2kbp의 17S-rDNA를 agarose 전기영동상에서 분리하였다. 이를 pBR 322에 cloning하여 wild type의 17S-rDNA probe와 colony hybridization시켜 선별하였다. 그중 5-19 균주의 recombinant plasmid로부터 17S-rDNA 의 전사 orientation위치가 pBR322의 tetracyline내성 유전자 쪽으로 삽입되어 있는 것을 확인하였다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.254-254
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• 2006

The sensitivity of plasmid DNA (pDNA) to S1 nuclease, an enzyme to cleave a single-strand DNA, was dramatically modulated through a supramolecular assembly (polyion complex micelle) with a synthetic block copolymer, poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL). The pDNA condensed in stoichiometric charge ratio was cleaved into 7 fragments each being 10/12, 9/12, 8/12, 6/12, 4/12, 3/12, and 2/12 of the original DNA length, on the other hand, the pDNA condensed in higher charge ratios (>4), were digested into non-specific manner. Condensation of the pDNA was investigated from two viewpoints that how does the rigid DNA molecules fold and condense and how does the condensation influence their biological activity.

• Journal of Gastric Cancer
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• 제7권1호
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• pp.9-15
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• 2007

목적: DNA 메틸화는 암 발생과정에 있어 중요한 기전 중 하나이다. DNA 메틸화는 DNMT (DNA methyltransferase)에 의해 매개되는데 이중 DNMT3b가 암세포에서 주로 암억제 유전자의 메틸화 정도롤 조절하는 것으로 알려져 있다. 저자들은 DNMT3b 유전자의 촉진자의 다형성과 한국인에서 위암발생의 연관성을 알아보고자 하였다. 대상 및 방법: 2001년 12월에서 2002년 12월까지 가톨릭대학교 성모병원에서 위암으로 진단받고 위 절제술을 받은 사람 중에서 176명과 같은 기간동안 내시경 검사를 시행했던 사람들 중 위암과 관련이 없는 경우 70명을 대상으로 하였다. DNMT3b 촉진자 다형성은 연쇄효소중합반응과 제한분절 길이 다형성 분석으로 유전형을 관찰하였다. 위암 환자에서 대립유전자 및 유전자형을 대조군과 비교하여 이런 다형성이 한국인에서 위암의 감수성을 증가시키는가에 대하여 연구하였다. 결과: DNMT3b 촉진자의 유전형은 환자군에서 14.8% (CC), 71.6% (CT), 13.6% (TT)를 보였고, 대조군에서 40% (CC), 42.9% (CT), 17.1% (TT)를 보였다. CT 이종접합체군에서 약 4.5배(OR 2.13; 95% CI, 2.324~8.803), TT 동종접합체군에서는 약 2.2배(교차비 1.42; 95% 신뢰구간, 0.899~5.165)의 위암발생률의 증가를 보였다. T 변이체 전체로는 약 3.8배의 위험률 증가를 보였다(교차비 1.88; 95%신뢰구간 2.040~7.251). 위암의 병기나 조직학적 소견, Helicobacter pylori 감염과는 유의한 관계를 보이지 않았다. 결론: DNMT3b 촉진자의 다형성은 T 변이체에서 한국인에서 위암 발생 위험도를 증가시킨다. 이러한 다형성과 위암의 병기, 조직학적 유형, Helicobacter pylori 감염과는 관련이 없었다.