• 한국해양학회지:바다
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• 제15권1호
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• pp.25-35
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• 2010

플랑크톤의 종다양성은 특정 지역의 수계환경 변화 모니터링에 있어 중요 생태지표로써, 환경 평가에 유용한 정보로 사용되고 있다. 기존의 종다양성 평가는 주로 형태학적 형질에 근거한 종동정을 통해 이루어졌으나, 많은 시간과 전문성을 필요로 하고 연구자의 주관적 판단에 의존하는 단점이 있다. 따라서, 본 연구에서는 채수된 환경시료에 대해 보다 빠르고 정확한 플랑크톤 종다양성을 파악하기 위하여 분자마커를 활용한 분자모니터링 기법을 도입하였다. 서낙동강(김해교)과 남해 연얀(남해도) 정점에서 각각 채수된 환경시료에서 DNA를 추출한 후 18S nuclear ribosomal RNA 유전자를 대상으로 중합효소연쇄반응을 수행하였다. 클로닝 과정을 통해 만들어진 각각의 클론 라이브러리에서 클론을 무작위로 선택하여 제한효소절편다형성 패턴분석을 한 후 특이성을 가지는 클론을 선별하였다. 김해교에서는 60개 블론을 대상으로 44개의 특이적 클론을 선별하였고 남해에서는 150개 클론을 대상으토 27개의 클론을 선별하였다. 이틀 클론틀에 대한 염기서열 분석결과 다양한 계통분류군에 속승하는 플랑크톤의 종조성 결과를 보여주었다(김해교: Heterokontophyta(7), Ciliophora(23), Dinophyta(l), Chytridiomycota(l), Rotifera(I), Arthropoda (11), 남해: Ciliophora( 4), Dinophyta(3), Crγptophyta(l)，Arthropoda(19)). 본 연구를 통하여 분자마커를 활용한 분자모니터링 기법이 기존 형태학적 형질에 근거한 분석이 가지는 한계를 보완하여 채수된 환경시료의 종조성 분석에 효율적으로 사용될 수 있다고 판단된다.

• Parasites, Hosts and Diseases
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• 제53권2호
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• pp.237-242
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• 2015

Analysis of ancient DNA (aDNA) extracted from Ascaris is very important for understanding the phylogenetic lineage of the parasite species. When aDNAs obtained from a Joseon tomb (SN2-19-1) coprolite in which Ascaris eggs were identified were amplified with primers for cytochrome b (cyt b) and 18S small subunit ribosomal RNA (18S rRNA) gene, the outcome exhibited Ascaris specific amplicon bands. By cloning, sequencing, and analysis of the amplified DNA, we obtained information valuable for comprehending genetic lineage of Ascaris prevalent among pre-modern Joseon peoples.

• 원예과학기술지
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• 제34권2호
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• pp.294-304
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• 2016

Members of the genus Brassica, which are known as oil crops or cruciferous vegetables, are widely cultivated in Canada, Australia, Asian and Europe. Because Brassica species have high yields, are well adapted to their environments, and are self-incompatible, the germplasm is abundant. Previous studies have reported abundant genetic diversity even within Brassica subspecies. In Korea, fresh cabbage leaves are eaten with roast meat, and to meet the current popular demand, new varieties are being increasingly bred. To determine the genetic diversity and relationships among the cabbage vegetables in Korea, we evaluated the genetic variation of 18 accessions based on 5S and 18S ribosomal RNA (rRNA) gene sequences. We detected many variable nucleotide sites, especially in the 5S rRNA gene sequences. Because the length of the 18S rRNA gene might influence the dissimilarity rate statistics, we used both the 5S and 18S sequences to analyze the phylogenetic relationships. S7 (B. oleracea) showed the most distant phylogenetic relationship with the other Brassica species. Interestingly, B2 (B. oleracea), B15, and B18 (B. campestris) have three different types of leaf profiles, and were divided into one group, and the other Brassica species formed another group. Statistical analysis of interspecies and intraspecies genetic distances revealed that B. campestris L. showed higher genetic diversity than B. oleracea L. This work provides additional data that facilitates the evaluation of the genetic variation and relationships among Brassica species. The results could be used in functional plant breeding programs to improve Brassica crops.

• 한국약용작물학회지
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• 제14권3호
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• pp.178-182
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• 2006

둥굴레 유전자원의 유연관계를 위한 기초 자료를 얻고자 둥굴레속 식물 수집종 10종에서 18S ribosomal RNA를 암호화하는 18S rDNA 영역의 염기서열을 결정하고 그 특성을 분석한 결과를 요약하면 다음과 같다. 둥굴레속 10종의 18S rDNA 영역 전체의 길이는 $913{\sim}914bp$로 비슷하였으나, 총 8개 지점에서 염기의 치환 및 결실에 의한 변이가 발생하였다. 전위는 $T{\rightarrow}C$전위가 4개 지점에서 발생하였고, $A{\rightarrow}G$ 전위가 1개 지점에서 발생하였으며, 전좌는 $C{\rightarrow}A$ 전좌가 1개 지점에서 발생하여 전위가 전좌보다 5배 만큼 발생하였다. 결실은 2개 지점에서 발생하였다. 18S rDNA의 염기의 조성은 adenine $23.09{\sim}23.33%$, guanine $23.33{\sim}23.52%$, thymine $25.60{\sim}25.85%$, cytosine $27.38{\sim}27.79%$로 pyrimidine계가 purine계보다 많았다. 18S rDNA의 A + T 함량은 $48.80{\sim}49.18%$로 평균 48.99%였고, G+C 함량은 $50.82{\sim}51.20%$로 평균51.01%였다. 다중 정렬에 의해 염기서열을 비교한 결과 $99.7{\sim}100%$ 일치하여 종간에 차이가 적었다.

• 대한임상검사과학회지
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• 제48권4호
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• pp.327-334
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• 2016

최근 사람과 가축에 항균제의 과도한 사용으로 감염병을 일으키는 병원성 세균들의 항균제 내성이 증가하고 있다. 본 연구에서는 PCR과 염기서열분석법을 이용하여 충청지역 일개의 대학병원에 의뢰된 임상검체와 같은 지역에서 사육된 닭으로부터 분리된 P. mirabilis 균주를 대상으로 16S ribosomal RNA methyltransferase(RMTase) 유전자와 integron을 조사하였다. 또한 Repetitive extragenic palindromic sequence-based PCR (REP-PCR)을 이용하여 P. mirabilis 균주들의 역학적 연관성 조사하였다. 총 38균주의 P. mirabilis 중에서 임상검체로부터 분리된 7균주 (18.4%)만이 RMTases 유전자를 가지고 있었는데 이들은 모두 amikacin, tobramycin, 및 gentamicin에 내성을 나타냈다. 또한 대상균주 중 23균주(60.5%)가 class 1 integron을 가지고 있는 것으로 나타났으며 class 2 및 class 3 integron은 검출되지 않았다. 본 연구에서 확인된 integrons에는 aminoglycoside 내성유전자(aadA2, aadA5, aadA7, 및 aacCA5), ${\beta}$-lactmam 내성유전자($bla_{PSE}$), erythromycin 내성유전자(ereA), lincosamides 내성유전자(linF), 및 trimethoprim 내성유전자(dfrA12, dfrA17 및 dfrA32)등이 유전자 카세트로 포함되어 있었다. 본 연구결과 RMTase 유전자는 임상검체로부터 분리된 P. mirabilis 균주에만 확산되어 있었던 반면 class 1 integrons는 임상검체와 닭으로부터 분리된 P. mirabilis 균주에 광범위하게 확산되어 있음을 확인할 수 있었다. 게다가 닭으로부터 분리된 균주 중에는 동일한 REP-PCR 밴드패턴을 보인 균주들이 있었는데 이는 닭들 사이에서 P. mirabilis 균주가 수평확산 되었음을 의미한다. P. mirabilis 균주에서 항균제 내성유전자의 확산을 막기 위해서는 내성유전자 지속적인 모니터링과 감시가 필요할 것으로 사료된다.

• 대한의생명과학회지
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• 제18권3호
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• pp.299-306
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• 2012

Recently, the prevalence of 16S rRNA methylase conferring high-level resistance to aminoglycosides has been increasing in Gram-negative bacilli globally. We determined the prevalence and genotype of these methylase-producing bacteria, and characterized the co-resistance to ${\beta}$-lactam antibiotics and quinolone in Gram-negative clinical isolates collected in 2010 at a hospital in Korea. Among 65 amikacin-resistant isolates screened from 864 Gram-negative bacilli (GNB), 16S rRNA methylase genes were detected from 49 isolates, including Acinetobacter baumannii (43), Klebsiella pneumoniae (2), Proteus mirabilis (2) and Serratia marcescens (1), Empedobacter brevis (1). All of the 16S rRNA methylase genotype was armA and no variant sequences of amplified PCR products for armA were noted. The 16S rRNA methylase producing bacteria showed much higher resistance to aminoglycoside for Enterobacteriaceae and glucose non-fermenting (NF)-GNB and to imipenem for glucose NF-GNB, than the non-producing isolates. All of the 16S rRNA methylase producing Enterobacteriaceae had the extended-spectrum-${\beta}$-lactamase. In addition, two K. pneumoniae concurrently produced both plasmid-mediated AmpC ${\beta}$-lactamase and qnrB gene. All of the amikacin-resistant A. baumannii (43) co-harbored armA 16S rRNA methylase and $bla_{OXA-23}$ carbapenemase. In conclusion, 16S rRNA methylase producing bacteria were very prevalent among GNB in South Korea, and were commonly associated with co-resistance, including carbapenem and quinolone.

• The Plant Pathology Journal
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• 제40권2호
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• pp.171-191
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• 2024

Identification of Helicotylenchus species is very challenging due to phenotypic plasticity and existence of cryptic species complexes. Recently, the use of rDNA barcodes has proven to be useful for identification of Helicotylenchus. Molecular markers are a quick diagnostic tool and are crucial for discriminating related species and resolving cryptic species complexes within this speciose genus. However, DNA barcoding is not an error-free approach. The public databases appear to be marred by incorrect sequences, arising from sequencing errors, mislabeling, and misidentifications. Herein, we provide a comprehensive analysis of the newly obtained, and published DNA sequences of Helicotylenchus, revealing the potential faults in the available DNA barcodes. A total of 97 sequences (25 nearly full-length 18S-rRNA, 12 partial 28S-rRNA, 16 partial internal transcribed spacer [ITS]-rRNA, and 44 partial cytochrome c oxidase subunit I [COI] gene sequences) were newly obtained in the present study. Phylogenetic relationships between species are given as inferred from the analyses of 103 sequences of 18S-rRNA, 469 sequences of 28S-rRNA, 183 sequences of ITS-rRNA, and 63 sequences of COI. Remarks on suggested corrections of published accessions in GenBank database are given. Additionally, COI gene sequences of H. dihystera, H. asiaticus and the contentious H. microlobus are provided herein for the first time. Similar to rDNA gene analyses, the COI sequences support the genetic distinctness and validity of H. microlobus. DNA barcodes from type material are needed for resolving the taxonomic status of the unresolved taxonomic groups within the genus.

• Parasites, Hosts and Diseases
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• 제54권5호
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• pp.631-636
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• 2016

This study aimed to develop a multiplex-touchdown PCR method to simultaneously detect 3 species of protozoan parasites, i.e., Cryptosporidium parvum, Giardia lamblia, and Cyclospora cayetanensis, the major causes of traveler's diarrhea and are resistant to standard antimicrobial treatments. The target genes included the Cryptosporidium oocyst wall protein for C. parvum, Glutamate dehydrogenase for G. lamblia, and 18S ribosomal RNA (18S rRNA) for C. cayetanensis. The sizes of the amplified fragments were 555, 188, and 400 bps, respectively. The multiplex-touchdown PCR protocol using a primer mixture simultaneously detected protozoa in human stools, and the amplified gene was detected in > $1{\times}10^3$ oocysts for C. parvum, > $1{\times}10^4$ cysts for G. lamblia, and > 1 copy of the 18S rRNA gene for C. cayetanensis. Taken together, our protocol convincingly demonstrated the ability to simultaneously detect C. parvum, G. lamblia, and C. cayetanenesis in stool samples.

• 식물분류학회지
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• 제53권1호
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• pp.32-37
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• 2023

Spiraea prunifolia f. simpliciflora Nakai is a perennial shrub widely used for horticultural and medicinal purposes. We simultaneously obtained the complete plastid genome (plastome) and nuclear ribosomal gene transcription units, 45S nuclear ribosomal DNA (nrDNA) and 5S nrDNA of S. prunifolia f. simpliciflora, using Illumina short-read data. The plastome is 155,984 bp in length with a canonical quadripartite structure consisting of 84,417 bp of a large single-copy region, 18,887 bp of a short single-copy region, and 26,340 bp of two inverted repeat regions. Overall, a total of 113 genes (79 protein-coding genes, 30 tRNAs, and four rRNAs) were annotated in the plastome. The 45S nrDNA transcription unit is 5,848 bp in length: 1,809 bp, 161 bp, and 3,397 bp for 18S, 5.8S, and 26S, respectively, and 261 bp and 220 bp for internal transcribed spacer (ITS) 1 and ITS 2 regions, respectively. The 5S nrDNA unit is 512 bp, including 121 bp of 5S rRNA and 391 bp of intergenic spacer regions. Phylogenetic analyses showed that the genus Spiraea was monophyletic and sister to the clade of Sibiraea angustata, Petrophytum caespitosum and Kelseya uniflora. Within the genus Spiraea, the sections Calospira and Spiraea were monophyletic, but the sect. Glomerati was nested within the sect. Chamaedryon. In the sect. Glomerati, S. prunifolia f. simpliciflora formed a subclade with S. media, and the subclade was sister to S. thunbergii and S. mongolica. The close relationship between S. prunifolia f. simpliciflora and S. media was also supported by the nrDNA phylogeny, indicating that the plastome and nrDNA sequences assembled in this study belong to the genus Spiraea. The newly reported complete plastome and nrDNA transcription unit sequences of S. prunifolia f. simpliciflora provide useful information for further phylogenetic and evolutionary studies of the genus Spiraea, as well as the family Rosaceae.

• 식물분류학회지
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• 제52권4호
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• pp.262-268
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• 2022

The complete chloroplast genome (cp genome) sequence of Clematis calcicola J. S. Kim (Ranunculaceae) is 159,655 bp in length. It consists of large (79,451 bp) and small (18,126 bp) single-copy regions and a pair of identical inverted repeats (31,039 bp). The genome contains 92 protein-coding genes, 36 transfer RNA genes, eight ribosomal RNA genes, and two pseudogenes. A phylogenetic analysis based on the cp genome of 19 taxa showed high similarity between our cp genome and data published for C. calcicola, which is recognized as a species endemic to the Korean Peninsula. The complete cp genome sequence of C. calcicola reported here provides important information for future phylogenetic and evolutionary studies of Ranunculaceae.