• Title/Summary/Keyword: Polyphyletic

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Evidence for Polyphyletic Origin of the Members of the Subsection IV Cyanobacteria as Determined by 16S rRNA Analysis (16S rRNA 분석에 의한 Subsection IV cyanobacteria 균주들의 다계통성 기원의 증거)

  • Shin, Yong Kook;Seo, Pil-Soo
    • Journal of Life Science
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    • v.26 no.10
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    • pp.1202-1206
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    • 2016
  • Unicellular cyanobacterial strains of Subsections I and II and filamentous cyanobacterial strains of Subsection III have been shown to be polyphyletic, heterocystous strains of Subsections IV and V, both of which were previously reported to be monophyletic. In this study, the small subunit ribosomal RNA (16S rRNA) sequences of 13 strains of cyanobacteria - one strain, Oscillatoria nigro-viridis PCC7112, of the Subsection III, 6 strains including genus Anabaena, Nostoc, Tolypothrix, Calothrix and Scytonema of the Subsection IV, and 6 strains including genus Hapalosiphon, Fischerella and Chlorogloeopsis of the Subsection V - were determined. The phylogenetic analysis of cyanobacteria was carried out using the 16S rRNA sequences. The results of the phylogenetic analyses of 16S rRNA sequences, based on Neighbour-joining, maximum-parsimony, and maximum-likelihood methods, indicated that the members of Subsection IV were not monophyletic but polyphyletic. In addition, the phylogenetic results strongly indicated that the genus Scytonema in Subsection IV could be a common ancestor of heterocystous cyanobacteria in Subsection IV and V. Furthermore, the phylogenetic analyses revealed that the genus Anabaena could be phylogenetically diverse and that cyanobacterial strains in Subsection IV might be polyphyletic, whereas those in Subsection V could be monophyletic, as reported before. The results for the genus Anabaena indicate that it should be reclassified.

Phylogenetic Relationships among Diverse Dinoflagellate Species Occurring in Coastal Waters off Korea Inferred from Large Subunit Ribosomal DNA Sequence Data

  • Kim, Keun-Yong;Kim, Chang-Hoon
    • ALGAE
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    • v.22 no.2
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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.

New Report of Three Unrecorded Species in Trichoderma harzianum Species Complex in Korea

  • Jang, Seokyoon;Kwon, Sun Lul;Lee, Hanbyul;Jang, Yeongseon;Park, Myung Soo;Lim, Young Woon;Kim, Changmu;Kim, Jae-Jin
    • Mycobiology
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    • v.46 no.3
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    • pp.177-184
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    • 2018
  • The genus Trichoderma (Hypocreaceae, Ascomycota) consists of globally distributed fungi. Among them, T. harzianum, one of the most commonly collected Trichoderma species, had been known as a polyphyletic or aggregate species. However, a total of 19 species were determined from the polyphyletic groups of T. harzianum. Thus, we explored Korean "T. harzianum" specimens that were collected in 2013-2014. These specimens were re-examined based on a recent study with translate elongation factor 1-alpha ($EF1{\alpha}$) sequences to reveal cryptic Trichoderma species in Korea. As a result, four different species, T. afroharzianum, T. atrobruneum, T. pyramidale, and T. harzianum, were identified. Except T. harzianum, the other three species have not been reported in Korea. In this work, we describe these species and provide figures.

Phylogenetic Evaluation of Stereoid Fungi

  • Yoon, Sung-Il;Kim, Seon-Young;Lim, Young-Woon;Jung, Hack-Sung
    • Journal of Microbiology and Biotechnology
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    • v.13 no.3
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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.

Phylogenetic study of trichaptum inferred from nuclear ribosomal DNA sequences

  • Ko, Kwon-Soo;Hong, Soon-Gyu;Jung, Hack-Sung
    • Journal of Microbiology
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    • v.35 no.2
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    • pp.79-86
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    • 1997
  • For the phylogenetic study of the genus Trichaptum, nuclear ribosomal DNA sequences from eight strains of four Trichaptium species were examined. Phylogenetic trees were constructed using molecular data on 18 rDNA and 5.8S rDNA and thei ITSs. Parsimony analyses of the Trichaptum species showed that T. biforme and T. laricinum made a monophyletic group respectively, suggesting that each species is phylogenetically independent. However, T. abietum represented a polyphyletic group and T. fusco-violaceum formed a polytomous group, suggesting that these species could be in the process of evolutionary differentiation. Examination of base substitutions of the 18S rRNA gene reveals that the C-T transition is most predominant and that there is a stronger transition bias between closely related organisms rather than between distantly related ones.

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Genetic Relationships of Coprinus spp. on the Basis of Sequences in ITS II Region (먹물버섯류(Coprinus spp.)의 ITS II 영역 염기서열에 의한 유연관계 분석)

  • Park, Dong-Suk;Go, Seung-Joo;Kim, Yang-Sup;Seok, Soon-Ja;Song, Jae-Kyeong;Yeo, Yun-Soo;Ryu, Jin-Chang;Sung, Jae-Mo
    • The Korean Journal of Mycology
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    • v.27 no.1 s.88
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    • pp.27-31
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    • 1999
  • The internal transcribed spacer II regions (ITS II) of the ribosomal DNA gene repeat from Coprinus spp. were amplified using polymerase chain reaction (PCR) and sequenced. Sequences from 11 species including Coprinus comatus, C. atramentarius, C. micaceus, C. lagopus, C. cinereus, C. rhizophorus, C. flocculosus, C. radians, and C. echinosporus were compared. The spacer regions of them were $253{\sim}275$ nucleotide in length and partially contained 5.8S and 25S. The reciprocal homologies of each ITS II sequence among these strains were in the range of $50.6{\sim}100%$. According to the analysis of ITS II sequences, Coprinus spp. were classified into three clusters. Cluster I consisted of Coprinus lagopus, C. cinereus, C. echinosporus, C. rhizophorus, C. niveus, and C. atramentarius. Cluster II comprised C. micaceus, C. flocculosus, C. radians, and C. disseminatus. On the other hand C. comatus is in Cluster III even though this species is belonging to the section Coprinus in morphological aspect. These results suggest that Coprinus comatus, which was considered as a type species of the genus Coprinus in morphological classification, gives a doubt of monophyletic evolution and is assumed to be paraphyletic or polyphyletic.

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Molecular Characterization of Marine Cyanobacteria from the Indian Subcontinent Deduced from Sequence Analysis of the Phycocyanin Operon (cpcB-IGS-cpcA) and 16S-23S ITS Region

  • Premanandh, Jagadeesan;Priya, Balakrishnan;Teneva, Ivanka;Dzhambazov, Balik;Prabaharan, Dharmar;Uma, Lakshmanan
    • Journal of Microbiology
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    • v.44 no.6
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    • pp.607-616
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    • 2006
  • Molecular characterization of ten marine cyanobacterial isolates belonging to the order Oscillatoriales was carried out using the phycocyanin locus (cpcBA-IGS) and the 16S-23S internally transcribed spacer region. DNA sequences from the phycocyanin operon discriminated ten genotypes, which corresponded to seven morphotypes identified by traditional microscopic analysis. The cpcB coding region revealed 17% nucleotide variation, while cpcA exhibited 29% variation across the studied species. Phylogenetic analyses support the conclusion that the Phormidium and Leptolyngbya genera are not monophyletic. The nucleotide variations were heterogeneously distributed with no or minimal informative nucleotides. Our results suggest that the discriminatory power of the phycocyanin region varies across the cyanobacterial species and strains. The DNA sequence analysis of the 16S-23S internally transcribed spacer region also supports the polyphyletic nature of the studied oscillatorian cyanobacteria. This study demonstrated that morphologically very similar strains might differ genotypically. Thus, molecular approaches comprising different gene regions in combination with morphological criteria may provide better taxonomical resolution of the order Oscillatoriales.

Molecular Phylogeny and Divergence Time Estimation of the Soft Coral Dendronephthya gigantea (Alcyonacea: Nephtheidae)

  • Kim, Boa;Kong, So-Ra;Song, Jun-Im;Won, Yong-Jin
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.3
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    • pp.327-332
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    • 2008
  • Soft coral Dendronephthya gigantea (Verrill, 1864) is a conspicuous species dominating shallow sea waters of Jejudo Island, Korea. Recently its whole mitochondrial genome sequencing was completed by us and the sequence information provided an opportunity to test the age of Octocorallia and time of evolutionary separation between some representative orders of the subclass Octocorallia. Molecular phylogenetic analyses based on 13 mitochondrial protein encoding genes revealed a polyphyletic relationship among octocorallians representing two orders (Alcyonacea and Gorgonacea) and four families (Alcyoniidae, Nephtheidae, Briareidae, and Gorgoniidae). Estimates of divergence times among octocorallians indicate that the first splitting might occur around end of or after Cretaceous period (50-79 million years ago (Ma)). The age is relatively young compared to the long history of stony sea corals (>240 Ma). Taken together our result suggests a possible relatively recent radiating evolution at least in the order Alcyonacea and Gorgonacea. Molecular dating and phylogenetic analysis based on much broader taxon sampling and many genes might give an insight into this interesting hypothesis.

Diversity of the Lichenized Fungi in King George Island, Antarctica, Revealed by Phylogenetic Analysis of Partial Large Subunit rDNA Sequences

  • Lee, Jin-Sung;Lee, Hong-Kum;Hur, Jae-Seoun;Andreev, Mikhail;Hong, Soon-Gyu
    • Journal of Microbiology and Biotechnology
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    • v.18 no.6
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    • pp.1016-1023
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    • 2008
  • Lichens are predominant and important components of flora in the terrestrial ecosystem of Antarctica. However, relatively few researches on the phylogenetic position of Antarctic lichen-forming fungi have been accomplished. In this study, partial sequences of nuclear large subunit rDNAs from 50 Antarctic specimens were obtained and the phylogeny was reconstructed. Antarctic lichen species were distributed in 4 orders, including the monophyletic order Agyrales, paraphyletic orders Pertusariales and Teloschistales, and polyphyletic order Lecanorales. Species diversity was highest in the order Lecanorales, followed by Teloschistales and Pertusariales. Based on the phylogeny and sequence similarity analyses, it is proposed that the taxonomy of Stereocaulon alpinum, Physcia caesia, Usnea aurantiacoatra, and Cladonia species should be revised by careful examination of their phenotypic and molecular characteristics. Six species known to be endemic to Antarctica, Catillaria corymbosa, Himantormia lugubris, Leptogium puberulum, Pertusaria pertusa, Rhizoplaca aspidophora, and Umbilicaria antarctica, formed unique lineages, implying independent origins in the Antarctic area.