• Title/Summary/Keyword: nuclear ribosomal DNA

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Phylogenetic Relationships of the Polyporaceae Based on Gene Sequences of Nuclear Small Subunit Ribosomal RNAs

  • Kim, Seon-Young;Jung, Hack-Sung
    • Mycobiology
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    • v.29 no.2
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    • pp.73-79
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    • 2001
  • The Polyporaceae is a chaotic mass of genera having poroid hymenophores in the Aphyllophorales. To classify the Polyporaceae into more natural groups, phylogenetic analyses were performed using nuclear small subunit ribosomal DNA sequences. Thirty-six species from the families of the Polyporaceae, the Hymenochaetaceae, the Ganodermataceae, the Corticiaceae, the Bondarzewiaceae, the Meruliaceae, the Steccherinaceae and the Lentinaceae were phylogenetically compared. By performing maximum parsimony analysis, seven phylogenetically meaningful groups were identified and discussed. The hyphal system, presence or absence of clamps, and the type of rot were found as important characters in defining the groups. Each group was phylogenetically significant enough to be a core member of each family when the Polyporaceae was split into smaller and more natural families.

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First Record of Two Pseudopolydora (Annelida: Spionidae) Species in Korea

  • Lee, Geon Hyeok;Yoon, Seong Myeong;Min, Gi-Sik
    • Animal Systematics, Evolution and Diversity
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    • v.38 no.1
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    • pp.26-33
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    • 2022
  • Two Pseudopolydora polychaetes, P. bassarginensis and P. reticulata, originally described from Peter the Great Bay in Russia and Taiwan, respectively, were recorded firstly in Korea with DNA information. Two species are known to have distinct morphological characteristics that are separated from other Pseudopolydora species. They are characterized by reticulate pigmentations on the dorsal sides of the anterior chaetigers, a longitudinal black band-like pigmentation on the caruncle, and black paired spots on the ventral sides of the anterior chaetigers. These two species can be distinguished morphologically from each other by the length of the caruncle. Methyl green staining pattern of the species is a good method for delimiting Pseudopolydora species. The partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA (16S rDNA), and the nuclear 18S ribosomal DNA (18S rDNA) from Korean specimens of the two species were determined. The morphological descriptions and images of the two Pseudopolydora species are provided.

Analysis of the Phylogenetic Relationships in the Genus Spiraea Based on the Nuclear Ribosomal DNA ITS Region (핵 리보솜 DNA ITS 부위에 의한 조팝나무속 식물종의 계통 관계 분석)

  • Huh, Man-Kyu
    • Journal of Life Science
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    • v.22 no.3
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    • pp.285-292
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    • 2012
  • Genus Spiraea is composed of many long-lived woody species that are primarily distributed throughout Asia and Europe. In this study, we evaluated a representative sample of the 38 taxa in the world, including 14 in Korea, with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within the genus. The molecular data allowed us to resolve well-supported clades in the taxa. In 47 world accessions (38 taxa: 14 Korean taxa, 33 world taxa, and 9 overlapping taxa), total alignment length was 689 positions, of which 452 were parsimony informative, 527 variable, 75 singleton, and 159 constant characters. Although the phylogenic tree showed that many taxa of genus Spiraea were well separated from each other, many branches were not congruent with the morphological characteristics and geographical distributions of the genus. There were 430 segregating sites and the nucleotide diversity (${\pi}$) value was 0.281. Under the neutral mutation hypothesis, the probability that the Tajima test statistic (D) is positive (2.325) is more than 0.5. Therefore, there may be a site at which natural selection, which increases genetic variation, is operating.

Molecular phylogeny of Daucus (Apiaceae): Evidence from nuclear ribosomal DNA ITS sequences

  • Lee, Byoung Yoon;Park, Chong-Wook
    • Journal of Species Research
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    • v.3 no.1
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    • pp.39-52
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    • 2014
  • The Apiaceae genus Daucus consists of approximately 25 species (including carrots) which are characterized by the presence of bracts in pedunculate umbels, dorsally compressed mericarps, hairs on primary ridges, and uniseriately arranged spines on the secondary ridges of the fruit. Taxonomically, Daucus has been considered to be one of the most problematic genera in the Apiaceae due to the highly variable fruit morphology. Despite taxonomic controversy and economic importance of the genus, no rigorously constructed estimate of phylogenetic relationships exists. To examine generic limit and relationships among species of Daucus and its putatively related taxa, phylogenetic analyses of characters derived from nuclear ribosomal DNA ITS sequences were conducted. Two major clades emerged within Daucus, but neither of them have been previously recognized using morphological characters. The phylogeny also provides taxonomic status of recently reported new species of Daucus, D. arcanus and D. conchitae.

A New Report of Prionospio kirrae (Annelida: Spionidae) from Korea

  • Lee, Geon Hyeok;Min, Gi-Sik
    • Animal Systematics, Evolution and Diversity
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    • v.38 no.2
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    • pp.91-97
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    • 2022
  • Spionid polychaete Prionospio kirrae Wilson, 1990 is newly reported from the Yellow Sea in Korea. This species is characterized by four pairs of branchiae, which are apinnate on chaetigers 2-4 and pinnate on chaetiger 5, a caruncle extending to the posterior end of chaetiger 1, the presence of a distinctly high dorsal crest on chaetiger 11, and the presence of tridentate hooded hooks with rounded apical teeth. Sequences of partial mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA(16S rDNA), and the nuclear 18S ribosomal DNA(18S rDNA) of the species are determined from Korean specimens.

Genetic Variation of Rice Populations Estimated Using nrDNA ITS Region Sequence

  • Wang, Dong;Hong, Soon-Kwan
    • Korean Journal of Plant Resources
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    • v.27 no.3
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    • pp.249-255
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    • 2014
  • The rice belonging to Oryza sativa is not only has significant economic importance, for it is the major source of nutrition for about 3 billion all around the world. But also plays a vital role as a model organism, because it has a number of advantages to be a model plant, such as efficient transformation system and small genome size. Many methods and techniques have been conducted to attempt to distinguish different Oryza sativa species, such as amplified fragment length polymorphism (AFLP), random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and so on. However, studies using sequence analysis of internal transcribed spacer (ITS), a region of ribosomal RNA has not been reported until now. This study was undertaken with an aim to understand the phylogenetic relationships among sixteen isolates of Oryza sativa collected from abroad and fifteen isolates collected from Korea, using ribosomal RNA (rRNA) internal transcribed spacer (ITS) sequences to compare the phylogeny relationships among different Oryza sativa species. The size variation obtained among sequenced nuclear ribosomal DNA (nrDNA) ITS region ranged from 515bp to 1000bp. The highest interspecific genetic distance (GD) was found between Sfejare 45 (FR12) and Anapuruna (FR15). Taebong isolate showed the least dissimilarity of the ITS region sequence with other thirty isolates. This consequence will help us further understanding molecular diversification in intra-species population and their phylogenetic analysis.

Utility of taxon-specific molecular markers for the species identification of herbarium specimens: an example from Desmarestia japonica (Phaeophyceae, Desmarestiales) in Korea

  • Lee, Sang-Rae;Lee, Eun-Young
    • Fisheries and Aquatic Sciences
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    • v.21 no.3
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    • pp.8.1-8.6
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    • 2018
  • Desmarestia japonica (Phaeophyceae, Desmarestiales) was recently established from the Japanese ligulate Desmarestia and is morphologically similar to D. ligulata. This species has been reported only from Japan. However, the taxonomic reports based on additional regional distributions are needed to clarify this taxonomic entity and its species boundaries. Because Desmarestia species have restricted distributions in Korea, we reexamined herbarium specimens of D. ligulata deposited at the National Institute of Biological Resources (South Korea). To improve the amplification efficiency of the polymerase chain reaction and avoid contamination by the DNA of other organisms, we developed taxon-specific molecular markers suitable for DNA barcoding of Desmarestia species. Nuclear ribosomal small subunit RNA (18S rDNA) and mitochondrial cytochrome c oxidase 1 (cox1) regions were selected as target DNA. As a result, both were successfully isolated from herbarium specimens of D. japonica acquired over 10 years. These molecular markers provide useful genetic information for herbarium specimens for which conventional molecular analysis is challenging.