• ALGAE
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• 제22권2호
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• pp.57-67
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• 2007

We analyzed the nuclear-encoded large subunit ribosomal RNA gene (LSU rDNA) sequences of 19 dinoflagellates occurring in costal waters off Korea and reconstructed a phylogenetic tree containing 74 representative species from 37 distinct genera. Of these, the LSU rDNA sequences of Amylax triacantha (Jörgensen) Sournia, Gonyaulax verior Sournia (= Amylax diacantha Meunier), Gyrodinium fissum (Levander) Kofoid et Swezy, Katodinium glaucum (Lebour) Lebour III, Noctiluca scintillans (Macartney) Kofoid et Swezy, Oxyphysis oxytoxoides Kofoid, and Pyrophacus steinii (Schiller) Wall et Dale are reported for the first time. Our LSU rDNA tree consistently placed Oxyrrhis marina Dujardin and N. scintillans at the most primitive positions, giving rise to a strongly supported monophyletic group of typical dinoflagellate species belonging to the Dinophyceae. The phylogenetic relationships among the typical dinoflagellates, however, were not resolved in the higher taxonomic levels in general. Only genera at terminal branches were usually supported with high confidence. The Dinophysiales, represented by Dinophysis species and O. oxytoxoides, formed a strongly supported monophyletic assemblage. The Gymnodiniales and Peridiniales were recovered as polyphyletic groupings. Members of the Gonyaulacales were consistently grouped together, but lacked statistical support. Within this order, the Ceratiaceae and Goniodomataceae each formed a monophyletic group, but the Gonyaulacaceae was polyphyletic. The phylogenetic relationships of the Gonyaulacaceae were generally congruent with differences in the combinations of the apical pore complex, hypothecal organization and thecal formula.

• 한국균학회지
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• 제51권4호
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• pp.411-417
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• 2023

In July 2023, previously unrecorded fungi belonging to the genus Helvella were collected from the city of Taebaek, South Korea. These fungi are morphologically similar to Helvella crispa, but their differences include a wide, saddle-shaped apothecium and white hair on the receptacle surface. By analyzing DNA sequences combining the internal transcribed spacer (ITS) and nuclear ribosomal large subunit (nrLSU) regions and comparing them with various related species of Helvella, the collected fungi were identified as H. orienticrispa.

• 한국균학회지
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• 제51권3호
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• pp.239-243
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• 2023

The Golovinomyces biocellatus complex is known to consist of powdery mildew from the Golovinomyces genus, associated with host plants from the Lamiaceae family. Recent molecular phylogenetic analyses have resolved the taxonomic composition of this complex, and Golovinomyces biocellatus sensu stricto is considered to be a pathogen of Glechoma species, globally. However, this paper presents a new finding of Golovinomyces salviae on Glechoma longituba, besides its original host species of Salvia. This information was inferred by molecular phylogenetic analyses from the multi-locus nucleotide sequence dataset of intergeneric spacer (IGS), internal transcribed spacer (ITS), large subunit (LSU) of rDNA, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. Further, the asexual morphology of this fungus is described and illustrated.

• 생명과학회지
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• 제23권10호
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• pp.1260-1266
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• 2013

본 연구에서는 H. marmoreus 3-10균주와 H. marmoreus 1-1균주의 ribosomal DNA (rDNA) cluster의 분석이 수행되었다. Small subunit (SSU)와 intergenic spacer 2 (IGS 2)는 부분적으로 염기서열이 결정되었고, internal transcribed spacer 1 (ITS 1), 5.8S, internal transcribed spacer 2 (ITS 2), large subunit (LSU), intergenic spacer 1 (IGS 1), 5S는 완전하게 염기서열이 결정 되었다. 팽이버섯 H. marmoreus 3-10균주와 H. marmoreus 1-1균주의 rDNA cluster는 총 7,049 bp로 결정되었다. SSU은 1,796 bp, ITS1은 229 bp, 5.8S은 153 bp, ITS2는 223 bp, LSU은 3,348 bp, IGS1은 390 bp, IGS2은 900 bp로 염기서열이 분석되었다. 결정된 rDNA cluster의 총 7,049 bp 중에서 17 bp가 다름이 확인되었고, 각각 SSU (2 bp), ITS (3 bp), LSU (9 bp), IGS (3 bp)에서 차이를 확인하였다. ITS regions의 2차 구조 결과 5개의 stem-loop가 있음이 드러났다. 흥미롭게도, 이들 stem-loop 사이에서 stem-loop V에서 한 개의 상이한 염기가 다른 2차 구조를 나타냄을 확인하였다.

• Ocean Science Journal
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• 제40권3호
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• pp.155-166
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• 2005

New PCR primers (N=18) were designed for the isolation of complete SSU to LSU rDNA sequences from the dinoflagellate Alexandrium tamarense. Standard PCR, employing each primer set selected for amplifications of less than 1.5 kb, successfully amplified the expected rDNA regions of A. tamarense (Korean isolate, HY970328M). Complete SSU, LSU rDNAs and ITS sequences, including 5.8S rDNA, were recorded at 1,800 bp, 520 bp and 3,393 bp, respectively. The LSU rDNA sequence was the first report in Alexandrium genus. No intron was found in the LSU rRNA coding region. Twelve D-domains within the LSU rDNA were put together into 1,879 bp (44.4% G+C), and cores into 1514 bp (42.8% G+C). The core sequence was significantly different (0.0867 of genetic distance, 91% sequence similarity) in comparison with Prorocentrum micans (GenBank access. no. X16108). The D2 region was the longest in length (300 bp) and highly variable among the 12 D-domains. In a phylogenetic analysis using complete LSU rDNA sequences of a variety of phytoplankton, A. tamarense was clearly separated with high resolution against other species. The result suggests that the sequence may resolve the taxonomic ambiguities of Alexandrium genus, particularly of the tamarensis complex.

• ALGAE
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• 제29권2호
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• pp.75-99
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• 2014

A small dinoflagellate, Ansanella granifera gen. et sp. nov., was isolated from estuarine and marine waters, and examined by light microscopy, scanning electron microscopy, and transmission electron microscopy. In addition, the identity of the sequences (3,663-bp product) of the small subunit (SSU), internal transcribed spacer (ITS) region (ITS1, 5.8S, ITS2), and D1-D3 large subunit (LSU) rDNA were determined. This newly isolated, thin-walled dinoflagellate has a type E eyespot and a single elongated apical vesicle, and it is closely related to species belonging to the family Suessiaceae. A. granifera has 10-14 horizontal rows of amphiesmal vesicles, comparable to Biecheleria spp. and Biecheleriopsis adriatica, but greater in number than in other species of the family Suessiaceae. Unlike Biecheleria spp. and B. adriatica, A. granifera has grana-like thylakoids. Further, A. granifera lacks a nuclear fibrous connective, which is present in B. adriatica. B. adriatica and A. granifera also show a morphological difference in the shape of the margin of the cingulum. In A. granifera, the cingular margin formed a zigzag line, and in B. adriatica a straight line, especially on the dorsal side of the cell. The episome is conical with a round apex, whereas the hyposome is trapezoidal. Cells growing photosynthetically are $10.0-15.0{\mu}m$ long and $8.5-12.4{\mu}m$ wide. The cingulum is descending, the two ends displaced about its own width. Cells of A. granifera contain 5-8 peripheral chloroplasts, stalked pyrenoids, and a pusule system, but lack nuclear envelope chambers, a nuclear fibrous connective, lamellar body, rhizocysts, and a peduncle. The main accessory pigment is peridinin. The SSU, ITS regions, and D1-D3 LSU rDNA sequences differ by 1.2-7.4%, >8.8%, and >2.5%, respectively, from those of the other known genera in the order Suessiales. Moreover, the SSU rDNA sequence differed by 1-2% from that of the three most closely related species, Polarella glacialis, Pelagodinium bei, and Protodinium simplex. In addition, the ITS1-5.8S-ITS2 rDNA sequence differed by 16-19% from that of the three most closely related species, Gymnodinium corii, Pr. simplex, and Pel. bei, and the LSU rDNA sequence differed by 3-4% from that of the three most closely related species, Protodinium sp. CCMP419, B. adriatica, and Gymnodinium sp. CCMP425. A. granifera had a 51-base pair fragment in domain D2 of the large subunit of ribosomal DNA, which is absent in the genus Biecheleria. In the phylogenetic tree based on the SSU and LSU sequences, A. granifera is located in the large clade of the family Suessiaceae, but it forms an independent clade.

• Journal of Microbiology
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• 제44권1호
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• pp.29-34
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• 2006

The purpose of this study was to develop molecular identification method for medical mushrooms and their preparations based on the nucleotide sequences of nuclear large subunit (LSD) rDNA. Four specimens were collected of each of the three representative medicinal mushrooms used in Korea: Ganoderma Incidum, Coriolus versicolor, and Fomes fomentarius. Fungal material used in these experiments included two different mycelial cultures and two different fruiting bodies from wild or cultivated mushrooms. The genomic DNA of mushrooms were extracted and 3 nuclear LSU rDNA fragments were amplified: set 1 for the 1.1-kb DNA fragment in the upstream region, set 2 for the 1.2-kb fragment in the middle, and set 3 for the 1.3-kb fragment downstream. The amplified gene products of nuclear large subunit rDNA from 3 different mushrooms were cloned into E. coli vector and subjected to nucleotide sequence determination. The sequence thus determined revealed that the gene sequences of the same medicinal mushroom species were more than $99.48\%$ homologous, and the consensus sequences of 3 different medicinal mushrooms were more than $97.80\%$ homologous. Restriction analysis revealed no useful restriction sites for 6-bp recognition enzymes for distinguishing the 3 sequences from one another, but some distinctive restriction patterns were recognized by the 4-bp recognition enzymes AccII and HhaI. This analysis was also confirmed by PCR-RFLP experiments on medicinal mushrooms.

• Mycobiology
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• 제41권4호
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• pp.191-201
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• 2013

Distinguishing individual Russula species has been difficult due to extensive phenotypic plasticity and obscure morphological and anatomical discontinuities. Due to highly similar macroscopic features, such as the presence of a red-cap, species identification within the Russula subgenus Amoenula is particularly difficult. Three species of the subgenus Amoneula have been reported in Korea. We used a combination of morphology and three molecular markers, the internal transcribed spacer (ITS), 28S nuclear ribosomal large subunit (LSU), and RNA polymerase II gene (RPB2), for identification and study of the genetic diversity of Russula subgenus Amoenula in Korea. We identified only two species in Korea (R. mariae and R. violeipes); these two species were indistinguishable according to morphology and LSU, but were found to be reciprocally monophyletic species using ITS and RPB2. The markers, ITS, LSU, and RPB2, have been tested in the past for use as DNA barcoding markers, and findings of our study suggest that ITS and RPB2 had the best performance for the Russula subgenus Amoneula.

• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1708-1711
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• 2007

The Streptomyces coelicolor M145 genome harbors six copies of divergent rRNA operons that differ at ${\sim}0.2%$ and ${\sim}0.6%$ of the nucleotide positions in small subunit (SSU) and large subunit (LSD) rRNA genes, respectively. When these rRNA genes are expressed, a single cell may harbor three different kinds of SSU rRNA and five kinds of LSU rRNA. Primer extension analyses revealed that all of the heterogeneous rRNA molecules are expressed and assembled into ribosomes. This finding and the maintenance of the intragenomic variability of rRNA operons imply the existence of functional divergence of rRNA species in this developmentally complex microorgamsm.

• ALGAE
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• 제31권3호
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• pp.219-230
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• 2016

The Euglena deses group are common freshwater species composed of E. adhaerens, E. carterae, E. deses, E. mutabilis, and E. satelles. These species are characterized by elongated cylindrical worm-like cell bodies and numerous discoid chloroplasts with a naked pyrenoid. To understand the cryptic diversity, species delimitation and phylogenetic relationships among members of the group, we analyzed morphological data (light and scanning electron microscopy) and molecular data (nuclear small subunit [SSU] and large subunit [LSU] rDNAs and plastid SSU and LSU rDNAs). Bayesian and maximum likelihood analyses based on the combined four-gene dataset resulted in a tree consisting of two major clades within the group. The first clade was composed of two subclades: the E. mutabilis subclade, and the E. satelles, E. carterae, and E. adhaerens subclade. The E. mutabilis subclade was characterized by a lateral canal opening at the anterior end and a single pellicular stria, whereas the E. satelles, E. carterae, and E. adhaerens subclade was characterized by an apical canal opening at the anterior end of the cell and double pellicular striae. The second clade consisted of 20 strains of E. deses, characterizing by a subapical canal opening at the anterior end and double pellicular striae, but they showed cell size variation and high genetic diversity. Species boundaries were tested using a Bayesian multi-locus species delimitation method, resulting in the recognition of five cryptic species within E. deses clade.