• Parasites, Hosts and Diseases
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• 제51권3호
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• pp.363-367
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• 2013

The prevalence of Toxoplasma gondii infection in birds has epidemiological significance because birds are indeed considered as a good indicator of environmental contamination by T. gondii oocysts. In this study, the prevalence of T. gondii in 313 house sparrows in Lanzhou, northwestern China was assayed by the modified agglutination test (MAT). Antibodies to T. gondii were positive in 39 (12.46%) of 313 samples (MAT titer ${\geq}$ 1:5). Tissues of heart, brain, and lung from the 39 seropositive house sparrows were tested for T. gondii DNA, 11 of which were found to be positive for the T. gondii B1 gene by PCR amplification. These positive DNA samples were typed at 9 genetic markers, including 8 nuclear loci, i.e., SAG1, 5'- and 3'-SAG2, alternative SAG2, SAG3, GRA6, L358, PK1, c22-8 and an apicoplast locus Apico. Of them, 4 isolates were genotyped with complete data for all loci, and 2 genotypes (Type II variants; ToxoDB #3 and a new genotype) were identified. These results showed that there is a potential risk for human infection with T. gondii in this region. To our knowledge, this is the first report of T. gondii seroprevalence in house sparrows in China.

• 생명과학회지
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• 제18권7호
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• pp.907-911
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• 2008

무(Raphanus sativus L.)는 세계적으로 중요한 작물 중의 하나이다. 십자화과 식물 종자 생산에서 원하지 않은 내교잡에 의한 종자 결실로 오염이 발생하므로 씨의 순수성 검증은 매우 중요하다. 재배종 진주 대평 무(R. sativus cv. Daepeng)와 백자 무(R. sativus cv. Backza)의 교잡 분석을 실시하였다. 알로자임으로 상업적으로 이용되는 잡종 제1세대($F_1$) 무에 있어서 씨의 순수성을 평가하였다. 웅성과 자성 양친 360개체에 27개 대립유전자좌위를 조사하였다. 특히 Par-1 ($aa{\times}bb$), Lap-1($aa{\times}bb$), Est-1 ($aa{\times}bb$)에서 명확한 잡종 밴드를 나타내었다. Est-1 대립유전자좌위에서 자성 배우체로부터 기원된 것이 15개체(8.3%)가 발견되었고, 웅성 배우체로부터 기원된 것이 26개체(14.4%)가 발견되었다. 또한 다양도 측면에서 양친 계통에 비해 잡종 계통에서 높은 유전적 다양도를 유지하고 있었다. 샤논의 정보지수(Shannon's index)를 이용한 표현형 다양도는 교잡 계통이 가장 높았다. 알로자임에 의한 무 계통의 교잡에 의한 종자 생성에서 씨에 대한 순수성 검증이 효과적으로 탐지되어 육종 연구에 기여할 수 있을 것으로 판단된다.

• Applied Biological Chemistry
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• 제50권3호
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• pp.137-146
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• 2007

지구 온난화의 주 원인인 온실가스의 배출을 감소시키기 위해서 바이오연료에 대한 필요성 및 중요성이 제기되어 왔다. 이미 유럽을 중심으로 오래전부터 바이오디젤 연료에 대한 연구가 시작되어 왔으며 지금은 상용화 단계에 접어들고 있는 반면, 국내 바이오디젤 연료에 대한 연구 수준은 이제 시작단계에 불과한 실정이다. 바이오디젤 연료로 사용가능한 유지작물의 지방산 조성에 따라 자동차 엔진 성능이 저하될 수 있다는 문제가 제기되었고, 이를 해결하고자 표준화된 바이오디젤 품질 규격서가 마련되어졌다. 유럽에서 마련된 바이오디젤 규격에 의하면 올레인산 함량이 높은 기름이 바이오디젤 연료로 적합하며, 유채기름이 다른 유지작물의 기름에 비하여 바이오디젤 연료에 적합하다고 알려져 있다. 따라서 국내 유지작물의 바이오디젤 연료화를 위한 품질 개량과 생산량 증대를 위해 생명공학기술을 이용한 품종 개량에 관한 연구 전략에 대해 고찰하였다.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.246-252
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• 2008

Tumor tissue is usually contaminated by normal tissue components, which reduces the sensitivity of analysis for exploring genetic alterations. Although microdissection has been adopted to minimize the contamination of tumor DNA with normal cell components, there is a concern over the amount of microdissected DNA not enough to be applied to array-CGH reaction. To amplify the extracted DNA, several whole genome amplification (WGA) methods have been developed, but objective comparison of the array-CGH outputs using different types of WGA methods is still scarce. In this study, we compared the performance of non-amplified microdissected DNA and DNA amplified in 2 WGA methods such as degenerative oligonucleotide primed (DOP)-PCR, and multiple strand displacement amplification (MDA) using Phi 29 DNA polymerase. Genomic DNA was also used to make a comparison. We applied those 4 DNAs to whole genome BAC array to compare the false positive detection rate (FPDR) and sensitivity in detecting copy number alterations under the same hybridization condition. As a result microdissected DNA method showed the lowest FPDR and the highest sensitivity. Among WGA methods, DOP-PCR amplified DNA showed better sensitivity but similar FPDR to MDA-amplified method. These results demonstrate the advantage and applicability of microdissection for array-CGH analysis, and provide useful information for choosing amplification methods to study copy number alterations, especially based on precancerous and microscopically invaded lesions.

• Ocean and Polar Research
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• 제33권3호
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• pp.303-308
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• 2011

Polar psychrophiles which thrive under extreme conditions such as cold temperature, high salinity, and high dose ultraviolet light, emerge as novel targets for biotechnology. To prevent genetic drift and the possibility of contamination by subculturing, cryopreservation was employed for two psychrophilic microalgae, Porosira sp. (KOPRI AnM0008) and Pyramimonas sp. (KOPRI AnM0046), which have anti-freeze activities. Five cryoprotectants (dimethyl sulphoxide, ethylene glycol, glycerol, methanol and propylene glycol) showed toxicity at 20-30% (v/v). The optimal cryoprotectant concentration and equilibration time were less than 20% and 10 min, respectively. Cryopreservation was carried out in the presence of cryoprotectants either by direct freezing in liquid nitrogen ($LN_2$) or controlled freezing using a controlled rate freezer followed by storage in the $LN_2$ tank. As a result, Pyramimonas sp. (KOPRI AnM0046), a psychrophilic chlorophyta was revived. Cryopreserved Porosira sp. was not revived from either freezing protocols probably due to the silicic cell wall and its relatively large cell size. In the case of Pyramimonas sp. (KOPRI AnM0046), the controlled freezing method showed higher revival yield than the direct freezing method.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1896-1907
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• 2018

Salmonellosis is commonly associated with meat and poultry products, but an increasing number of Salmonella outbreaks have been attributed to contaminated vegetables and fruits. Enteric pathogens including Salmonella enterica spp. can colonize diverse produce and persist for a long time. Considering that fresh vegetables and fruits are usually consumed raw without heat treatments, Salmonella contamination may subsequently lead to serious human infections. In order to understand the underlying mechanism of Salmonella adaptation to produce, we investigated the transcriptomics of Salmonella in contact with green vegetables, namely cabbage and napa cabbage. Interestingly, Salmonella pathogenicity island (SPI)-1 genes, which are required for Salmonella invasion into host cells, were up-regulated upon contact with vegetables, suggesting that SPI-1 may be implicated in Salmonella colonization of plant tissues as well as animal tissues. Furthermore, Salmonella transcriptomic profiling revealed several genetic loci that showed significant changes in their expression in response to vegetables and were associated with bacterial adaptation to unfavorable niches, including STM14_0818 and STM14_0817 (speF/potE), STM14_0880 (nadA), STM14_1894 to STM14_1892 (fdnGHI), STM14_2006 (ogt), STM14_2269, and STM14_2513 to STM14_2523 (cbi operon). Here, we show that nadA was required for bacterial growth under nutrient-restricted conditions, while the other genes were required for bacterial invasion into host cells. The transcriptomes of Salmonella in contact with cabbage and napa cabbage provided insights into the comprehensive bacterial transcriptional response to produce and also suggested diverse virulence determinants relevant to Salmonella survival and adaptation.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1079-1082
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• 2007

Chromosome microdissection and the reverse FISH technique is one of the most useful methods for the identification of structurally abnormal chromosomes. In particular, the laser microbeam microdissection (LMM) method allows rapid isolation of a target chromosome or a specific region of chromosomes without damage of genetic materials and contamination. Isolated chromosomes were directly amplified by the degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), and then the FISH probes labeled with spectrum green- or spectrum red-dUTP were generated by nick-translation. Whole chromosome painting (WCP) probes were successfully generated from only 5 copies of the chromosome. With this method, we produced 24 WCP probes for each human chromosome. We also tried to characterize a marker chromosome, which seemed to be originated from chromosome 11 on conventional banding technique. The marker chromosomes were isolated by the LMM method and analyzed by reverse FISH. We elucidated that the marker chromosome was originated from the short arm of chromosome 5 ($5p11{\to}pter$). A fully automated and computer-controlled LMM method is a very simple laboratory procedure, and enables rapid and precise characterization of various chromosome abnormalities.

• 한국산림과학회지
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• 제24권1호
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• pp.53-61
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• 1974

전남(全南) 신안군(新安郡) 흑산면(黑山面) 홍도리(紅島里)에 위치(位置)하고 있는 홍도(紅島)의 적송집단(赤松集團)을 대상(對象)으르 개체(個體)의 수형(樹型), 분지각(分枝角), 수피색(樹皮色), 추재율(秋材率) 침엽장(針葉長), 수지도(樹脂道)의 위치(位置)와 수(數) 등이 조사(調査)되었다. 홍도(紅島)에 자라는 송류(松類)는 적송(赤松)이 대부분(大部分)으로 필자(筆者)는 조사(調査)도중 단일주(單一株)의 해송치수(海松稚樹)를 발견(發見)하였을 뿐이다. 20년생(年生) 이상의 적송(赤松) 14개체(個體)의 침엽(針葉)을 검경(檢鏡)한바 어느 정도(程度)의 해송인자(海松因子)가 혼입(混入)되어 있었다. 밀엽형개체(密葉型個體)와 소엽형개체(疎葉型個體)를 볼 때 부수지도(副樹脂道)의 수(數)가 현저하게 적은 것이 특징(特徵)이며 특히 소엽형(疎葉型)의 경우 부수지도(副樹脂道)의 수(數)가 1.3 이라는 평균치(平均値)를 보였다. 현 단계로서는 과거부터 홍도(紅島)에 해송(海松)이 있었던 것으로 보기 어렵고 해안일대(海岸一帶)에 분포(分布)하는 해송(海松)으로부터 화분(花粉) 비산공여(飛散供與)되는 것으로 생각된다.

• Parasites, Hosts and Diseases
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• 제47권4호
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• pp.337-344
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• 2009

In a previous study, we reported our discovery of Acanthamoeba contamination in domestic tap water; in that study, we determined that some Acanthamoeba strains harbor endosymbiotic bacteria, via our molecular characterization by mitochondrial DNA restriction fragment length polymorphism (Mt DNA RFLP). Five (29.4%) among 17 Acanthamoeba isolates contained endosymbionts in their cytoplasm, as demonstrated via orcein staining. In order to estimate their pathogenicity, we conducted a genetic characterization of the endosymbionts in Acanthamoeba isolated from domestic tap water via 16S rDNA sequencing. The endosymbionts of Acanthamoeba sp. KA/WP3 and KA/WP4 evidenced the highest level of similarity, at 97% of the recently published 16S rDNA sequence of the bacterium, Candidatus Amoebophilus asiaticus. The endosymbionts of Acanthamoeba sp. KA/WP8 and KA/WP12 shared a 97% sequence similarity with each other, and were also highly similar to Candidatus Odyssella thessalonicensis, a member of the $\alpha$-proteobacteria. The endosymbiont of Acanthamoeba sp. KA/WP9 exhibits a high degree of similarity (85-95%) with genus Methylophilus, which is not yet known to harbor any endosymbionts. This is the first report, to the best of our knowledge, to show that Methylophilus spp. can live in the cytoplasm of Acanthamoeba.

• International Journal of Industrial Entomology and Biomaterials
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• 제23권1호
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• pp.167-174
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• 2011

The large bumblebee $Bombus$ $terrestris$, indigenous to Europe and adjacent areas and used extensively for high-value crop pollination, has been artificially introduced to several parts of the world. Here we show the occurrence of interspecific hybridization between the bumblebee species $B.$ $hypocrita$ $sapporoensia$ and $B.$ $terrestris$ under laboratory conditions. The mating and oviposition percentages resulting from the interspecific hybridization of a $B.$ $terrestris$ queen with a $B.$ $h.$ $sapporoensis$ male were higher than those resulting from the intraspecific mating of $B.$ $h.$ $sapporoensis$. Furthermore, a competitive copulation experiment indicated that the mating of $B.$ $h.$ $sapporoensis$ males with $B.$ $terrestris$ queens was 1.2-fold more frequent than the mating of these males with $B.$ $h.$ $sapporoensis$ queens. The interspecific hybridization of a $B.$ $terrestris$ queen with a $B.$ $h.$ $sapporoensis$ male produced either $B.$ $terrestris$ workers or the $B.$ $terrestris$ male phenotype, and the hybridization of a $B.$ $h.$ $sapporoensis$ queen with a $B.$ $terrestris$ male produced $B.$ $h.$ $sapporoensis$ males. Our results indicated that interspecific hybridization occurred between $B.$ $h.$ $sapporoensis$ and $B.$ $terrestris$. These results suggest that such hybridization will have a negative competitive impact and will cause genetic contamination of native bumblebees.