• 한국식물병리학회지
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• 제14권5호
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• pp.519-525
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• 1998

Intraspecific genetic diversity of Korean isolates of Phytophthora drechsleri was investigated based on PCR-RFLP of rDNA along with closely related species in the genus; P. cryptogea, P. melonis, P. erythroseptica, P. cinnamomi, P. cambivora and P. cactorum. Gene regions of nuclear small subunit and internal transcribed spacer (ITS) in rDNA were amplified with polymerase chain reaction and digested with 9 restriction enzymes. Phytophthora species was readily differentiated from each other based on the digestion patterns, however, P. cryptogea was not separable from some isolates of P. drechsleri. Twenty one isolates of P. drechsleri originated from 15 host plants were divided into three distinct groups designated as PdG1, PdG2 and PdG3, respectively. Four isolates in PdG1 were originated from green vegetables and tomato and nine isolates in PdG2 were mainly isolated from medicinal plants. The two groups showed 95.3% homology and four isolates of P. cyptogea came under the groups. However, Eight isolates in PdG3 collected from cucurbits were clearly differentiated from those of PdG1 and PdG2 by 66.5% homology, but completely matched with a Taiwan isolate of P. melonis. Results indicated that three distinct groups exist in Korean isolates of P. drechleri and each group has host preference. In addition, reclassification of the cucurbits isolates are reserved because of their distinct genetic characters from other intraspecific groups in P. drechsleri.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.26-28
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• 2003

"Epigenetics" means the study of heritable changes in gene-activity without changes in DNA sequences. Methylation of the cytosine residue in a CpG dinucleotide sequence is a characteristic of the vertebrate genome. In vertebrates, methylation of DNA mainly occurs at the 5′-position of cytosine in a CpG dinucleotide forming 5-methylcytosine. Methylation of DNA plays a profound role in transcriptional repression of gene expression through several mechanisms. Generally, DNA of inactive genes is more heavily methylated than that of active ones; conversely demethylation of DNA reactivates gene expression in vivo and in vitro.

• 식물병연구
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• 제17권1호
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• pp.99-101
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• 2011

자낭균인 Taphrina wiesneri는 한국의 공원과 가로수에 주로 식재되는 왕벚나무에 빗자루병을 일으키는 병원균이다. 한국과 일본에서 분리한 13개의 병원균에 대해 18S rDNA 염기서열 분석을 통한 계통학적 분석과 rDNA-IGS 영역에 대한 RFLP 분석을 실시하였다. 18S rDNA 염기서열 분석을 통한 계통도 분석결과 병원균은 2그룹으로 분류되었다. Hha I 제한효소를 이용한 rDNA-IGS 영역에 대한 RFLP 분석결과 B, C, D, G 4개의 패턴으로 나타났으며, 그중 G 패턴은 새로운 패턴이었다.

• Archives of Pharmacal Research
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• 제22권1호
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• pp.25-29
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• 1999

Psammaplin A, a natural bromotyrosine derivative from an associated form of two sponges (Poecillastra sp. and jaspis sp.) was found to possess the antimicrobial effect on the Gram-positive bacteria, especially on methicillin-resistant Staphylococcus aureus (MRSA). The minimal inhibitory concentration of psammaplin A against twenty one MRSAs ranged from 0.781 to 6.25 ${\mu}g/ml$, which that of ciprofloxacin was 0.391~3.125${\mu}g/ml$. Psammaplin A could not bind to penicillin binding protein, but inhibited the DNA synthesis and the DNA gyrase activity with the respective 50% (DNA synthesis) and 100% (DNA gyrase) inhibitory concentration 2.83 and 100 ${\mu}g/ml$. These results indicate that psammaplin A has a considerable antibacterial activity, although restricted to a somewhat narrow range of bacteria, probably by inhibiting DNA gyrase.

• 한국식품영양과학회지
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• 제39권6호
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• pp.805-812
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• 2010

본 연구에서는 조리법에 따른 마늘의 항 유전 독성 효과를 확인하기 위해 생마늘, 구운 마늘, 초절임 마늘의 에탄올 또는 메탄올 추출물을 백혈구에 처리한 후 comet assay를 수행하였다. 그 결과 조리 방법, 추출 용매에 상관없이 모든 추출물에서 DNA 손상 억제 효과가 것으로 나타났으며 활성산소인 $H_2O_2$에 대한 DNA 손상 억제 효과는 생마늘 메탄올 추출물에서, 지질과산화물인 HNE에 대한 DNA 손상 억제 효과는 구운 마늘 메탄올 추출물에서 높은 것으로 나타났다. 또한 $H_2O_2$로 유도한 스트레스에서는 마늘 추출물의 농도를 1, 5, 10, 50 ${\mu}g$/mL으로 증가시킬수록 DNA 손상 억제능이 좋은 것으로 나타난 반면 HNE로 스트레스를 유도한 군에서는 저농도인 1 ${\mu}g$/mL에서 오히려 높은 효능이 나타났다. 따라서 마늘의 항 유전 독성 효과는 한국인의 일반적인 마늘 섭취 형태인 생마늘, 구운 마늘, 초절임 마늘에 상관없이 탁월한 것을 알 수 있었다. 이와 같은 마늘의 항 유전 독성효과는 식재료로써의 마늘의 소비 및 의약품 소재로써의 이용성을 증진시킬 수 있는 자료가 될 것으로 사료된다.

• 한국발생생물학회지:발생과생식
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• 제14권1호
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• pp.13-19
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• 2010

We developed a novel dicistronic system for the expression of target cDNA sequences in the milk of transgenic animals using goat beta-casein/hGH fusion construct, pGbc5.5hGH (Lee, 2006) and internal ribosome entry site (IRES) sequences of encephalomyocarditis virus (EMCV). Granulocyte colony-stimulating factor (hG-CSF) cDNA was linked to 3' untranslated region of hGH gene in the pGbc5.5hGH via EMCV IRES sequences. Transgenic mice were generated by microinjection and transgene expression was examined in the milk and mammary gland of transgenic mice at 10 days of lactation. Northern blot analysis showed that hGH gene and hG-CSF cDNA were transcribed as a single dicistronic mRNA. The hG-CSF and hGH proteins were independently translated from the dicistronic mRNA and secreted into the milk of transgenic mice. The highest concentration of hG-CSF and hGH in the milk of transgenic mice were $237{\mu}g/m{\ell}$ and $8,990{\mu}g/m{\ell}$, respectively. In contrast, another hG-CSF expression cassette, in which hG-CSF genomic sequences were inserted into a commercial milk-specific expression vector (pBC1), generated a lower level ($91{\mu}g/m{\ell}$) of hG-CSF expression in the milk of transgenic mice. These results demonstrated that the novel pGbc5.5hGH-based dicistronic construct could be useful for an efficient cDNA expression in the milk of transgenic animals.

• 한국수산과학회지
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• 제20권6호
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• pp.569-572
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• 1987

지질산화생성물의 DNA 손상작용기구를 밝힐 목적으로 자동산화시킨 linoleic acid로부터 과산화물을 분리하고 DNA와 $37^{\circ}C$에서 반응시켜 경시적인 관산화물이 DNA 원상작용을 조사한 결과는 다음과 같다. 과산화물의 농도가 증가함에 따라 DNA가크게 송상되었으며, 반응 2일째에는 $422{\mu}g$ 이상의 농도에서는 DNA가 더욱 크게 손상을 받아 gel plate 상에서는 DNA band가 검출되지 않았다. 또, 이러한 DNA 손상능을 정량적으로 분석한 결과, 반응 1일에 대조구가 $30\%$의 감소율을 나타낸 반면, $844{\mu}g$의 농도에서는 2배량인 $60\%$의 감소율을 나타내었다. 과산화물과 DNA의 반응계에 각종 활성산소소거제를 첨가한 결과, 과산화물의 DNA 손상작용에 대한 활성산소종의 영향은 나타나지 않았다.

• Genomics & Informatics
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• 제8권1호
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• pp.58-61
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• 2010

CpG is the pair of nucleotides C and G, appearing successively, in this order, along one DNA strand. It is known that due to biochemical considerations CpG is relatively rare in most DNA sequences. However, in particular subsequences, which are a few hundred to a few thousand nucleotides long, the couple CpG is more frequent. These subsequences, called CpG islands, are known to appear in biologically more significant parts of the genome. The ability to identify CpG islands along a chromosome will therefore help us spot its more significant regions of interest, such as the promoters or 'start' regions of many genes. In this respect, I developed the CpG islands search tool, CpG Islands Detector, which was implemented in JAVA to be run on any platform. The window-based graphical user interface of CpG Islands Detector may facilitate the end user to employ this tool to pinpoint CpG islands in a genomic DNA sequence. In addition, this tool can be used to highlight potential genes in genomic sequences since CpG islands are very often found in the 5' regions of vertebrate genes.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7043-7048
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• 2014

Inhibition of heat shock protein 90 (Hsp90) leads to inappropriate processing of proteins involved in DNA damage repair pathways after DNA damage and may enhance tumor cell radio- and chemotherapy sensitivity. To investigate the potentiation of antitumor efficacy of lidamycin (LDM), an enediyne agent by the Hsp90 inhibitorgeldanamycin (GDM), and possible mechanisms, we have determined effects on ovarian cancer SKOV-3, hepatoma Bel-7402 and HepG2 cells by MTT assay, apoptosis assay, and cell cycle analysis. DNA damage was investigated with H2AX C-terminal phosphorylation (${\gamma}H2AX$) assays. We found that GDM synergistically sensitized SKOV-3 and Bel-7402 cells to the enediyne LDM, and this was accompanied by increased apoptosis. GDM pretreatment resulted in a greater LDM-induced DNA damage and reduced DNA repair as compared with LDM alone. However, in HepG2 cells GDM did not show significant sensitizing effects both in MTT assay and in DNA damage repair. Abrogation of LDM-induced $G_2/M$ arrest by GDM was found in SKOV-3 but not in HepG2 cells. Furthermore, the expression of ATM, related to DNA damage repair responses, was also decreased by GDM in SKOV-3 and Bel-7402 cells but not in HepG2 cells. These results demonstrate that Hsp90 inhibitors may potentiate the antitumor efficacy of LDM, possibly by reducing the repair of LDM-induced DNA damage.

• Toxicological Research
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• 제12권1호
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• pp.17-20
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• 1996

The effect of Fumonisin B1, a mycotoxin produced by Fusarium moniliforme on bacterial viruses P1 and Lambda, was investigated by the virus plaque assay. Fumonisin B1 inhibited the P1 viral multiplication in the concentration range from $100{\mu}g$/ml to $400{\mu}g$/ml. The inhibition was Fumonisin B1 concentration-dependent. Another bacterial virus Lambda multiplication was also inhibited by lower concentration of Fumonisin B1 ($10{\mu}g$/ml~$50{\mu}g$/ml). This inhibition was dependent on Fumonisin B1 and on virus-Fumonisin B1 reaction time. Sensitivity of bacteriophage Lambda to Fumonisin B1 was higher than that of P1 virus. Lambda vital DNA was treated in vitro with Fumonisin B1 at various concentration. Significant DNA fragmentation by Fumonisin 191 was observed in the agarose gel electrophoresis. Lambda viral DNA was partially digested even in the Fumonisin B1 $10{\mu}g$ and the level of its fragmentation was dependent on Fumonisin B1 amount up to $30{\mu}g$ per assay.