• BMB Reports
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• 제30권3호
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• pp.216-221
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• 1997

Changes in pathogenicity of old and successively-cultured isolates of Fusarium oxysporum f. sp. niveum have been observed and the concept that such cultures will become attenuated is generally accepted. However, the genetic basis for this phenomenon has not been studied. In an effort to identify a DNA marker closely linked to variations, DNA methylation was investigated both before and after the successive transfers of F. o. f. sp. niveum isolates on artificial media. A sector of mycelium in F. o. f. sp. niveum race 2 isolate (TXXID) which showed variation in pigmentation and colonial morphology occurred after 18 successive weekly transfers on potato dextrose agar (PDA). The sector characteristics were stable and did not change after more successive transfers. It was shown that DNA methylation preexists in ribosomal RNA gene (rDNA) of F. o. f. sp. niveum and that additional changes in DNA methylation occurred during successive culturing.

• Mycobiology
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• 제43권2호
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• pp.107-117
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• 2015

A mycoparasite, Scytalidium parasiticum sp. nov., isolated from the basidiomata of Ganoderma boninense causing basal stem rot of oil palm in Johor, Malaysia, is described and illustrated. It is distinct from other Scytalidium species in having smaller asci and ascospores (teleomorphic stage), longer arthroconidia (anamorphic stage), hyaline to yellowish chlamydospores, and producing a fluorescent pigment. The phylogenetic position of S. parasiticum was determined by sequence analyses of the internal transcribed spacers and the small-subunit ribosomal RNA gene regions. A key to identify Scytalidium species with teleomorphic stage is provided.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.406-414
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• 2003

Phylogenetic relationships of stereoid fungi were examined by comparing nuclear small subunit ribosomal RNA gene sequences. Stereoid taxa were scattered into several groups and the traditional Stereaceae proved to be polyphyletic. Srereum and Xylobolus were classified in the Stereaceae as the core group of stereoid fungi, and Amylostereum was grouped with Echinodontium of the Echinodontiaceae. Chondrostereum and Cystosrereum were clustered in the Stereaceae sensu Donk and Cymatoderma and Podoscypha in the Podoscyphaceae Reid. Columnocystis abietinum and C. ambigua were grouped with Meripilus giganteus and proved to be not included in the Chaetodermataceae sensu Nakasone. Lopharia cinerascens and L. mirabilis were grouped together but L. spadicea was unrelated to them, indicating that Lopharia is heterogeneous at a generic level.

• International Journal of Oral Biology
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• 제45권3호
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• pp.77-83
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• 2020

In the oral cavity, complex microbial community is shaped by various host and environmental factors. Extensive literature describing the oral microbiome in the context of oral health and disease is available. Advances in DNA sequencing technologies and data analysis have drastically improved the analysis of the oral microbiome. For microbiome study, bacterial 16S ribosomal RNA gene amplification and sequencing is often employed owing to the cost-effective and fast nature of the method. In this review, practical considerations for performing a microbiome study, including experimental design, molecular analysis technology, and general data analysis, will be discussed.

• International Journal of Oral Biology
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• 제35권1호
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• pp.21-25
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• 2010

This study was undertaken to develop species-specific forward and universal reverse PCR primers for the detection of Streptococcus sobrinus. These primers target the variable regions of the 16S ribosomal RNA coding gene (rDNA) and their specificity was tested against 10 strains of S. sobrinus strains and 20 different species of oral bacteria using serial dilutions of the purified genomic DNA of S. sobrinus ATCC $33478^T$. Our data show that species-specific amplicons were obtained from all the S. sobrinus strains tested but not from other species. Both direct and nested PCR could detect as little as 400 pg and 4 fg of genomic DNA from S. sobrinus ATCC $33478^T$, respectively. This result suggests that these PCR primers are highly specific and sensitive and applicable to the detection of S. sobrinus.

• Parasites, Hosts and Diseases
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• 제40권1호
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• pp.25-31
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• 2002

We describe a riboprinting scheme for identification of unknown Acanthamoeba isolates at the species level. It involved the use of PCR-RFLP of small subunit ribosomal RNA gene (riboprint) of 24 reference strains by 4 kinds of restriction enzymes. Seven strains in morphological group I and III were identified at species level with their unique sizes of PCR product and riboprint type by Rsa 1. Unique RFCP of 17 strains in group II by Dde I. Taq I and Hae III were classified into: (1) four taxa that were identifiable at the species level. (2) a subgroup of 4 taxa and a pair of 2 taxi that were identical with each other. and (3) a species complex of 7 taxa assigned to A. castellanii complex that were closely related. These results were consistent with those obtained by 18s rDNA sequence analysis. This approach provides an alternative to the rDNA sequencing for rapid identification of a new clinical isolate or a large number of environmental isolates of Acanthamoeba.

• 생명과학회지
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• 제2권2호
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• pp.108-119
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• 1992

근년에 개발된 효소적인 DNA증폭법을 이용하면 일차구조상의 단편적인 정보만 알면 단 수시간내 해석에 필요한 양의 DNA가 증폭되어 cDNA의 염기배열결정의 신속화, 간편화가 가능하게 되었다. 그러므로 유전자증폭법으로써 PCR법에 관해 기술한다. 그리고 리보좀 RNA는 분자시계로서 생물의 계통을 논하는 데에 있어서는 최적의 조건을 갖춘 고분자화합물이다. 이에 PCR법을 이용한 16S like 리보좀DNA의 증폭법을 다루고, PCR증폭산물의 염기배열결정법에 대해 서술한다. 또한 인위적인 leading error 등을 배제하고 신속한 자동해독과 시간적인 절약이 자동 DNA sequencer의 개발과 시판으로 가능하게 되어 cDNA의 형광색소표식 염기배열결정법에 대해서도 서술한다.

• 한국응용곤충학회:학술대회논문집
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• 한국응용곤충학회 2005년도 춘계 학술발표회
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• pp.189-189
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• 2005

• 한국환경보건학회지
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• 제35권3호
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• pp.187-190
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• 2009

Cryptosporidium spp. were detected in 17 of 135 swine lagoon samples from five farms by 18S ribosomal DNA locus and PCR. Seventeen positive samples identified were included two distinctive genotypes C. suis and Cryptosporidium sp. based on a small-subunit rRNA gene-based PCR-restriction fragment length polymorphism analysis. Cryptosporidium spp. were detected out of farrowing, farrowing and nursery (mix), and finishing. Prevalence rate was 12.6% with infection rates between 3.7 and 18.5%. We concluded that Cryptosporidium oocysts can persist in treated lagoon and potentially contaminate surface water through improper discharge. This study was undertaken for the evaluation of the infection status of the genotypes of Cryptosporidium spp. in swine lagoon.

• 한국임상수의학회지
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• 제37권1호
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• pp.57-59
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• 2020

A 3-year-old, captive female river cooter was presented with a 4-day history of progressive unilateral swelling of the right side of the head, lethargy, and anorexia. History, physical examination, and radiographic examination revealed an aural abscess. After administration of antibiotics and supportive care, surgical intervention was performed. Swab samples were collected from the tympanic cavity during surgery for cytology and antimicrobial susceptibility testing. Molecular analyses of 16S ribosomal RNA gene sequences identified Citrobacter spp. and Morganella morganii. The patient was treated with ciprofloxacin and meloxicam and recovered after 2 months. This report describes the successful correction of a unilateral aural abscess that responded well to surgical intervention and a properly selected antibiotic.