• Title/Summary/Keyword: Ribosomal DNA

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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.

An assessment of the taxonomic reliability of DNA barcode sequences in publicly available databases

  • Jin, Soyeong;Kim, Kwang Young;Kim, Min-Seok;Park, Chungoo
    • ALGAE
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    • v.35 no.3
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    • pp.293-301
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    • 2020
  • The applications of DNA barcoding have a wide range of uses, such as in taxonomic studies to help elucidate cryptic species and phylogenetic relationships and analyzing environmental samples for biodiversity monitoring and conservation assessments of species. After obtaining the DNA barcode sequences, sequence similarity-based homology analysis is commonly used. This means that the obtained barcode sequences are compared to the DNA barcode reference databases. This bioinformatic analysis necessarily implies that the overall quantity and quality of the reference databases must be stringently monitored to not have an adverse impact on the accuracy of species identification. With the development of next-generation sequencing techniques, a noticeably large number of DNA barcode sequences have been produced and are stored in online databases, but their degree of validity, accuracy, and reliability have not been extensively investigated. In this study, we investigated the extent to which the amount and types of erroneous barcode sequences were deposited in publicly accessible databases. Over 4.1 million sequences were investigated in three largescale DNA barcode databases (NCBI GenBank, Barcode of Life Data System [BOLD], and Protist Ribosomal Reference database [PR2]) for four major DNA barcodes (cytochrome c oxidase subunit 1 [COI], internal transcribed spacer [ITS], ribulose bisphosphate carboxylase large chain [rbcL], and 18S ribosomal RNA [18S rRNA]); approximately 2% of erroneous barcode sequences were found and their taxonomic distributions were uneven. Consequently, our present findings provide compelling evidence of data quality problems along with insufficient and unreliable annotation of taxonomic data in DNA barcode databases. Therefore, we suggest that if ambiguous taxa are presented during barcoding analysis, further validation with other DNA barcode loci or morphological characters should be mandated.

Restriction Analyses of PCR Amplified Partial SSU Ribosomal DNA to Distinguish Arbuscular Mycorrhizal Fungi from Other Fungi Colonizing Plant Roots

  • Lee, Jae-Koo;Tae, Moon-Sung;Eom, Ahn-Heum;Lee, Sang-Sun
    • Mycobiology
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    • v.31 no.2
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    • pp.68-73
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    • 2003
  • Roots of Glycine max and Miscanthus sinensis and soil samples were collected from various field sites at Goesan, Chungbuk in Korea. Microscopic observations of the roots indicated high colonization rates of both arbuscular mycorrhizal fungi(AMF) and other fungi. The partial small subunit of ribosomal DNA genes were amplified with the genomic DNA extracted from their roots by nested polymerase chain reaction(PCR) with universal primer NS1 and fungal specific primers AML Restriction fragment length polymorphism(RFLP) was analyzed using the combinations of three restriction enzymes, HinfI, AluI and AsuC21. Nucleotides sequence analysis revealed that ten sequences from Miscanthus sinensis and one sequence from Glycine max were close to those of arbuscular mycorrhizal fungi. Also, 33% of total clones amplified with NS31-AM1 primers from M. sinensis and 97% from G. max were close to Fusarium oxysporum or other pathogenic fungi, and they were successfully distinguished from AME Results suggested that these techniques could help to distinguish arbuscular mycorrhizal fungi from root pathogenic fungi in the plant roots. Especially, DNA amplified by these primers showed distinct polymorphisms between AMF and plant pathogenic species of Fusarium when digested with AsuC21.

Taxonomic Position of Korean Isolates of Rhizoctonia solani Based on RAPD and ITS Sequencing of Ribosomal DNA

  • Jeon, Young-Ah;Kim, Wan-Gyu;Kim, Dae-Ho;Kwon, Soon-Wo;Hong, Seung-Beom
    • The Plant Pathology Journal
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    • v.26 no.1
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    • pp.83-89
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    • 2010
  • Taxonomic position of 46 Korean isolates of Rhizoctonia solani which were classified into nine intraspecific groups by anastomosis and cultural characteristics was analyzed by randomly amplified polymorphic DNA (RAPD) and sequence analyses of the internal transcribed spacer (ITS) regions of ribosomal DNA. All the isolates within each group showed highly similar band patterns in RAPD. The ITS regions of the isolates within the same groups showed a high level of sequence similarity above 96.0% whereas similarities among different groups were below 94.4%. When compared with several reference strains of R. solani from foreign countries, all the Korean isolates were clustered with the foreign isolates belonging to the same groups in the phylogenetic tree. All six Korean strains of AG-4 were identified as HG-1 out of 3 subgroup of AG-4. We discussed taxonomic position of Korean isolates of R. solani and showed that sequence analysis with ITS regions could be a rapid and useful method for identification of intraspecific group of R. solani.

Phylogenetic Study of the Genus Pungitius (Gasterosteidae: Pisces) from Korea by the Sequence Analysis of 18s Ribosomal DNA (18s 리보좀 DNA 서열 분석에 의한 한국산 가시고기속 (genus Pungitius, Gasterosteidae: Pisces) 어류의 계통학적 연구)

  • Seo, Bo-Keun;Chae, Byung-Soo
    • Korean Journal of Ichthyology
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    • v.12 no.1
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    • pp.14-19
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    • 2000
  • The sequences of two fragments of 18s ribosomal DNA were determined to elucidate relationship between Pungitius sinensis and P. kaibarae. The proportion of G+C pair is 54.85% to 55.15% in P. kaibarae populations and 52.76% in P. sinensis. Number of substitutions ranges from 10~18 among the populations of P. kaibarae and up to 165 between P. sinensis and P. kaibarae. The value of sequence divergence were 0.0118~0.0195 among the populations of P. kaibarae and 0.2136~0.2306 between P. sinensis and P. kaibarae. The result of pairwise comparison of the sequences indicate that phylogenetic relationship between P. sinensis and P. kaibarae was differentiated to specific level.

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Molecular Identification of a Trichinella Isolate from a Naturally Infected Pig in Tibet, China

  • Li, Ling Zhao;Wang, Zhong Quan;Jiang, Peng;Zhang, Xi;Ren, Hui Jun;Cui, Jing
    • Parasites, Hosts and Diseases
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    • v.49 no.4
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    • pp.381-384
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    • 2011
  • The first human case with trichinellosis was reported in 1964 in Tibet, China. However, up to the present, the etiological agent of trichinellosis has been unclear. The aim of this study was to identify a Tibet Trichinella isolate at a species level by PCR-based methods. Multiplex PCR revealed amplicon of the expected size (173 bp) for Trichinella spiralis in assays containing larval DNA from Tibet Trichinella isolate from a naturally infected pig. The Tibet Trichinella isolate was also identified by PCR amplification of the 5S ribosomal DNA intergenic spacer region (5S ISR) and mitochondrial largesubunit ribosomal RNA (mt-lsrDNA) gene sequences. The results showed that 2 DNA fragments (749 bp and 445 bp) of the Tibet Trichinella isolate were identical to that of the reference isolates of T. spiralis. The Tibet Trichinella isolate might be classifiable to T. spiralis. This is the first report on T. spiralis in southwestern China.

Molecular Characterization of Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae) from Goats in the Western Part of India by LSU of Nuclear Ribosomal DNA

  • Kumar, Ashwani;Chaudhary, Anshu;Verma, Chandni;Singh, Hridaya Shanker
    • Parasites, Hosts and Diseases
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    • v.52 no.6
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    • pp.701-705
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    • 2014
  • The rumen parasite, Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae), is a highly pathogenic trematode parasite of goat (Capra hircus). It sucks blood that causes acute disease like anemia, and severe economic losses occur due to morbidity and mortality of the ruminant infected by these worms. The study of these rumen paramphistomes, their infection, and public health importance remains unclear in India especially in the western part of state Uttar Pradesh (U.P.), Meerut, India, where the goat meat consumption is very high. This paper provides the molecular characterization of G. crumenifer recovered from the rumen of Capra hircus from Meerut, U.P., India by the partial sequence of 28S rDNA. Nucleotide sequence similarity searching on BLAST of 28S rDNA from parasites showed the highest identity with those of G. crumenifer from the same host Capra hircus. This is the first report of molecular identification of G. crumenifer from this part of India.

PCR-RFLP Analysis of Ribosomal DNA Intergenic Spacer Region in Fusarium section Liseola. (Fusarium section Liseola 균주들에서 rDNA Intergenic Spacer 부위의 PCR-RFLP 분석)

  • 이경은;최영길;민병례
    • Korean Journal of Microbiology
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    • v.38 no.1
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    • pp.7-12
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    • 2002
  • The intergenic spacer (IGS) region of the ribosomal DNA of species in Fusarium section Liseola was analyzed by amplification and subsequent digestion with several restriction enzymes. The length of the amplified IGS region was about 2.6 Kb in all strains except F.moniliforme 12 Which was about 2.9 Kb. The enzymes, EcoRI, HincII, SalI, HindIII, PstI and SmaI, digested the IGS region and nine haplotypes were identified among 11 strains. In the dendrogram based on PCR-RFLP of IGS region combined the results of section Liseola in this study and section Elegans in previous study, variation in the IGS appears to offer considerable potential to resolve intraspecific relationship as well as interspecies or intersection.