• Parasites, Hosts and Diseases
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• 제37권4호
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• pp.197-213
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• 1999

Phylogeny is the evolutionary history of a group or the lineage of organisms and is reconstructed based on morphological, molecular and other characteristics. The genealogical relationship of a group of taxa is often expressed as a phylogenetic tree. The difficulty in categorizing the phylogeny is mainly due to the existence of frequent homoplasies that deceive observers. At the present time, cladistic analysis is believed to be one of the most effective methods of reconstructing a phylogenetic tree. Excellent computer program software for phylogenetic analysis is available. As an example, cladistic analysis was applied for nematode genera of the family Acuariidae, and the phylogenetic tree formed was compared with the system used currently. Nematodes in the genera Nippostrongylus and Heligmonoides were also analyzed, and the validity of the reconstructed phylogenetic trees was observed from a zoogeographical point of view. Some of the theories of parasite evolution were briefly reviewed as well. Coevolution of parasites and humans was discussed with special reference to the evolutionary relationship between Enterobius and primates.

• 식물병연구
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• 제28권2호
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• pp.57-60
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• 2022

Leaves of Chionanthus retusus were found to be damaged by leaf spot disease associated with a fungus in Iksan, Korea. Leaf spots were angular to irregular, vein-limited, scattered, 1-8 mm diameter, brownish-gray to dark brown when dry, with heavy fructification. The pathogen causes premature defoliation of C. retusus plant and was identified as Pseudocercospora chionanthi-retusi based on morphological and molecular-phylogenetic analyses. The phylogenetic tree was constructed using multi-locus DNA sequence data of partial actin (actA), partial translation elongation factor 1-alfa (tef1), partial DNA-directed RNA polymerase II second largest subunit (rpb2) genes, and internal transcribed spacer regions. Current study provides detail morphological description of P. chionanthi-retusi on C. retusus in Korea, with supports of phylogenetic analysis and pathogenicity test.

• 정보처리학회논문지D
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• 제10D권6호
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• pp.897-906
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• 2003

전통적인 동물 계통수(系統樹)는 초기발생 혈질에 기초하여 몸 구조가 단순한 것에서 복잡한 것으로 동물문(animal phylum)들을 배열하는 것이다. 현재 활발하게 연구 진행되는 분자수준에서의 분자계통 분류학(Molecular Systematics) 연구들이 이런 경향을 재평가하고 새로운 계통과 진화의 의미를 제시하고 있다. 본 논문에서는 한 염기서열로부터 획득할 수 있는 특성 값들을 추출하여 트레이닝 데이터를 생성하고, 생성된 데이터를 기반으로 데이터마이닝 기법중의 하나인 분류기법(classification) 을 사용하여 계통수를 생성하였다. 실험용 데이터는 미토콘드리아 염기서열을 사용하였으며 생물학분야에서 사용하는 분석 프로그램인 MEGA 프로그램을 사용하여 이를 증명하였다. 비록 마이닝을 수행한 결과는 생물학적 실험을 거쳐 정확성을 검증 받아야 하지만 인터넷상에 떠다니는 무수한 유전체들에 대한 유효한 분류기준을 제시할 수 있고 계통수 제작을 위한 실험에 소요되는 많은 시간과 노력들을 줄일 수 있다.

• 미생물학회지
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• 제24권4호
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• pp.400-405
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• 1986

이미 발표된 각 시료들의 tRNAAn 염기 서열을 이용하여 세통학적 연구플 하였나. archaebacterium안 H. volcano가 진핵생물과 연계된 결과는 진핵생물이 eubacteria와의 공통척 조상에셔 분화되지 않았음을 세시하며 Phage $T_{4}$와 $T_{s}$,의 연계 순서는 그들이 각각 독럽적으로 숙주로부터 분화되였음을 내타낸다. tRNA의 염기 순서의 상관관계를 이용한 연구 결과가 기존의 다른 연구 결고 및 고생물학적 기록들과도 일치함을 알 수 있었다.

• 한국동물위생학회지
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• 제36권1호
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• pp.23-30
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• 2013

An avian rotavirus (AvRV-2) was isolated from feces of broilers suffering from acute gastroenteritis in 2011. It was the first avian rotavirus isolated in Korea. To investigate the molecular characteristics of AvRV-2, the VP4, VP6, VP7 and NSP4 gene nucleotide sequences were determined and compared with those of rotavirus strains available in the GenBank database. The phylogenetic tree of VP7 gene showed that AvRV-2 had a high degree of nucleotide sequence homology (93.4% to 94.7%) with those of rotaviruses belonging to genotype G19 cluster. The phylogenetic tree of the VP4 gene revealed a high degree of nucleotide sequence homology (95.8% to 95.9%) with genotype P[30] rotaviruses isolated from chickens. The VP6 and NSP4 gene nucleotide sequences showed the highest identities with those of avian strains with 95.3% to 96.4% and 90.3% to 92.2%, respectively. Genetic characterization of the VP4, VP6, VP7 and NSP4 showed that AvRV-2 strain was most closely related to chicken rotavirus strains from Germany and Japan. Comparative nucleotide sequences and phylogenetic analysis indicated that avian rotavirus isolated from broilers belonged to genotype G19P[30] and it was the first report on avian rotavirus infection in Korea.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.643-649
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• 2010

Evaluation of the primary etiologic agents that cause aseptic meningitis outbreaks may provide valuable information regarding the prevention and management of aseptic meningitis. In Korea, an outbreak of aseptic meningitis caused by echovirus type 30 (E30) occurred from May to October in 2008. In order to determine the etiologic agent, CSF and/or stool specimens from 140 children hospitalized for aseptic meningitis at Soonchunhyang University Cheonan Hospital between June and October of 2008 were tested for virus isolation and identification. E30 accounted for 61.7% (37 cases) and echovirus 6 accounted for 21.7% (13 cases) of all the human enteroviruses (HEVs) isolates (60 cases in total). For the molecular characterization of the isolates, the VP1 gene sequence of 18 Korean E30 isolates was compared pairwise using the MegAlign with 34 reference strains from the GenBank database. The pairwise comparison of the nucleotide sequences of the VP1 genes demonstrated that the sequences of the Korean strains differed from those of lineage groups A, B, C, D, E, F, and G. Reconstruction of the phylogenetic tree based on the complete VP1 nucleotide sequences resulted in a monophyletic tree, with eight clustered lineage groups. All Korean isolates were segregated from other lineage groups, thus suggesting that the Korean strains were a distinct lineage of E30, and a probable cause of this outbreak. This manuscript is the first report, to the best of our knowledge, of the molecular characteristics of E30 strains associated with an aseptic meningitis outbreak in Korea, and their respective phylogenetic relationships.

• Journal of Ecology and Environment
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• 제41권1호
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• pp.9-18
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• 2017

Background: Species in the heterokont genus Synura are colonial and have silica scales whose ultrastructural characteristics are used for classification. We examined the ultrastructure of silica scales and molecular data (nuclear SSU rDNA and LSU rDNA, and plastid rbcL sequences) to better understand the taxonomy and phylogeny within the section Petersenianae of genus Synura. In addition, we report the first finding of newly recorded Synura species from Korea. Results: We identified all species by examination of scale ultrastructure using scanning and transmission electron microscopy (SEM and TEM). Three newly recorded species from Korea, Synura americana, Synura conopea, and Synura truttae were described based on morphological characters, such as cell size, scale shape, scale size, keel shape, number of struts, distance between struts, degree of interconnections between struts, size of base plate pores, keel pores, base plate hole, and posterior rim. The scales of the newly recorded species, which belong to the section Petersenianae, have a well-developed keel and a characteristic number of struts on the base plate. We performed molecular phylogenetic analyses based on sequence data from three genes in 32 strains (including three outgroup species). The results provided strong statistical support that the section Petersenianae was monophyletic, and that all taxa within this section had well-developed keels and a defined number of struts on the base plate. Conclusions: The phylogenetic tree based on sequence data of three genes was congruent with the data on scale ultrastructure. The resulting phylogenetic tree strongly supported the existence of the section Petersenianae. In addition, we propose newly recorded Synura species from Korea based on phylogenetic analyses and morphological characters: S. americana, S. conopea, and S. truttae.

• ALGAE
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• 제21권3호
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• pp.283-286
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• 2006

This study carried out phylogenetic analysis of dinoflagellate Gonyaulax polygramma which was responsible for a harmful algal bloom episode in Korea in 2004. Molecular phylogenetic tree inferred from the partial LSU rDNA data showed that G. polygramma came up among the monophyletic Gonyaulax clade, but did not have apparent genetic affiliation to other Gonyaulax species. This result appears to be consistent with characteristic morphological features of G. polygramma such as epitheca sharply tapering to the apex and thecal plates ornamented with numerous longitudinal striations.

• 한국환경생태학회지
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• 제32권6호
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• pp.566-574
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• 2018

한국산 나문재속 식물에 대한 계통학적 유연관계를 밝히고, 분자계통학적 연구를 통해 나문재속 종간 유연관계를 확인할 수 있는 분자마커를 찾아내기 위해 연구를 수행하였다. 핵 리보솜 DNA ITS와 엽록체 DNA matK, psbA-trnH 그리고 trnL-trnF를 분자마커로 사용하였다. ITS 영역은 칠면초와 해홍나물 그리고 해홍나물과 방석나물을 구분하지 못하였다. psbA-trnH와 trnL-trnF 영역의 염기서열은 칠면초와 방석나물을 구분하지 못하였다. 그러나 4종의 분자마커 영역을 조합하여 분석한 결과 나문재속 식물 5종이 각각 독립적인 계통을 형성하는 것을 확인하였다. 따라서 나문재속 계통관계 분석을 위해서 여러 개의 분자마커 조합이 유용할 것으로 판단된다. 나문재속 내 분류군 간의 계통관계를 명확히 밝히기 위해 차후에 좀 더 많은 생태학적, 형태학적 자료를 조사해야 할 것으로 보인다.

• 생명과학회지
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• 제21권7호
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• pp.939-946
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• 2011

미토콘드리아 산화효소(COI) 유전자의 서열을 이용하여 한국 내 육지플라나리아의 분류와 계통관계를 규명하였다. 유전자은행에서 Bipaliidae과의 종에 관한 기 발표된 서열을 계통분석을 위해 포함시켰다. 육지 플라나리아의 서열 배당은 387 bp에서 444 bp로 나타났으며 이런 차이는 염기 삽입에 기인하였다. COI 분석에 근거한 계통학적 분지도는 형태적 형질에 의한 결과와 일치하지 않았다. Bipalium nobile가 나머지 분류군(Bipalium adventitium, Bipalium venosum, Bipalium kewense, Bipalium multilineatum)을 포함하는 관계로 나타났다. 내부 가지의 분지군은 강하게 지지되었다(>91%). The phylogenic tree on COI 분석에 의한 계통도는 잘 분리되었다. 이들은 단계원을 형성하였다. 미토콘드리아 산화효소 유전자는 한국 내 육지 플라나리아 분류군을 동정하는데 유력한 도구가 될 수 있다.