• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.515-523
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• 2001

The dinoflagellates have some primitive nuclear features and are evolutionarily intermediate between prokaryotes and eukaryotes. The small subunit ribosomal RAN gene, the 5.8S ribosomal RNA gene, and the internal transcribed spacer (ITS) of Gonyaulax polyedra were cloned, and their sequences were analyzed to better understand their evolutionary position. The small subunit ribosomal RNA gene was 1,794 nt long, the large subunit ribosomal RNA gene was approximately 3,500 nt long, and the 5.8S ribosomal RNA gene was 159 nt long. The first internal transcribed spacer (ITS1) was 191 nt long, and the second internal transcribed spacer (ITS2) was 185 nt long. The intergenic spacer of the ribosomal RNA gene (IGS) was about 2,200 nt long, indicating that 5,800 nt of transcribed sequences were separated by roughly 2,200 nt of intergenic spacer. The ribosomal RNA genes were repeated many times and arranged in a head-to-tail, tandemly repeated manner. The repeating unit of ribosomal RNA gene of G. polyedra was proposed to be 8,000 nt long. Based on the lengths of ribosomal RNA, sequence alignments with representative organisms, and phylogenetic analysis on ribosomal RNA, G. polyedra appears to be one of the alveolates branched from the eukaryotic crown and, among dinoflagellates, it seems to not have emerged early.

• Journal of Microbiology
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• v.39 no.4
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• pp.265-272
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• 2001

Variation within the intergenic spacer(IGS) of the ribosomal DNA gene for twenty-two strains of E. oxysporum and its formae speciales was examined by PCR, couped with RELP analysis. The length of the amplified IGS region was about 2.6 kb in all strains except F.oxysporum f. sp. cucumer-inum from Korea and F. oxysporum f. sp. niveum. Those two strains were 2.5 kb long. Restriction digestion of IGS-RELP regions by Eco RI, NruI, HincII, SAlI, SmaI, BalIi, HindIII, XhoI and KpnI gave rise to nine IGS hapoltypes among all strains. Cluster analysis based on the presence of absence of comigrating restriction reagments show the two groups based on 44% genetic similarity. These results demonstrated that analysis of IGS showed some difference within and between F. oxysporum formae speciales.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.148-151
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• 2004

This study was carried out to elucidate phylogenetic relationship of a yellow lump, Phellinus linteus by comparing the nuclear ribosomal intergenic spacer (IGS) I region with that of other genera of basidiomycetes retrieved from Genbank. IGS I region of Phellinus linteus was 730 bp long and sequence homology was conserved in the 5' region, in particular $1{\sim}280\;bp$, and decreased in the direction toward the 3' end. ITS region was widely studied in phylogenies related to basidiomycetes, but IGS region was not well understood yet. Our study indicated that IGS region can be a good tool in phylogenetic study of basidiomycetes.

• Journal of Life Science
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• v.23 no.10
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• pp.1260-1266
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• 2013

The ribosomal DNA (rDNA) clusters of Hypsizygus marmoreus 3-10 and H. marmoreus 1-1 were analyzed in this study. The small subunit (SSU) and intergenic spacer 2 (IGS 2) was partially sequenced. The internal transcribed spacer 1 (ITS 1), 5.8S, internal transcribed spacer 2 (ITS 2), large subunit (LSU), intergenic spacer 1 (IGS 1), and 5S were completely sequenced. The rDNA clusters of H. marmoreus 3-10 and H. marmoreus 1-1 were 7,049 bp in length. The sequence of SSU rDNA, which corresponded to 18S rDNA, was 1,796 bp in length, and the sequence of LSU rDNA, which corresponded to 28S rDNA, was 3,348 bp in length. The ITS region that variable region and IGS region that non-transcribed spacer was 462 bp and 1,290 bp in length. The sequence of 5.8S rDNA and 5S rDNA was 153 bp and 43 bp in length, respectively. The 17 bp of the rDNA cluster in the H. marmoreus 3-10 strain was different to that in the H. marmoreus 1-1 strain, with 2 bp in the SSU, 3 bp in the ITS, 9 bp in the LSU, and 3 bp in the IGS. The analysis of the secondary structure revealed that the ITS regions of H. marmoreus 3-10 and H. marmoreus 1-1 have five stem-loop structures. Interestingly, among these structures, one different nucleotide sequence resulted in a different secondary structure in stem-loop V.

• 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.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2000.10a
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• pp.30.1-30
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• 2000

• Mycobiology
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• v.44 no.4
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• pp.314-318
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• 2016

Breeding the button mushroom requires genetic information about its strains. This study was undertaken to genetically characterize four domestically bred button mushroom strains (Saea, Saejung, Saedo, Saeyeon cultivars) and to assess the possibility of using the intergenic spacer 1 (IGS1) region of rDNA as a genetically variable region in the genetic characterization. For the experiment, 34 strains of Agaricus bisporus, two strains of A. bitorquis, and one strain of A. silvaticus, from 17 countries were used. Nucleotide sequence analysis of IGS1 rDNA in these 37 Agaricus strains confirmed that genetic variations exist, not only among the four domestic strains, but also between the four domestic strains and foreign strains. Crossing two different haploid strains of A. bisporus seems to generate genetic variation in the IGS1 region in their off-spring haploid strains. Phylogenetic analysis based on the IGS1 sequence revealed all A. bisporus strains could be differentiated from A. silvaticus and A. bitorquis strains. Five genetic groups were resolved among A. bisporus strains. Saejung and Saeyeon cultivars formed a separate genetic group. Our results suggest that IGS1 could be complementarily applied in the polymorphism analysis of button mushroom.

• Journal of Microbiology and Biotechnology
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• v.20 no.5
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• pp.853-861
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• 2010

High substrate costs decrease the profitability of polyhydroxyalkanoates (PHAs) production, and thus low-cost carbon substrates coming from agricultural and industrial residuals are tested for the production of these biopolymers. Among them, crude glycerol, formed as a by-product during biodiesel production, seems to be the most promising source of carbon. The object of this study was to characterize the mixed population responsible for the conversion of crude glycerol into PHAs by cultivation-dependent and -independent methods. Enrichment of the microbial community was monitored by applying the Ribosomal Intergenic Spacer Analysis (RISA), and the identification of community members was based on 16S rRNA gene sequencing of cultivable species. Molecular analysis revealed that mixed populations consisted of microorganisms affiliated with four bacterial lineages: ${\alpha}$, ${\gamma}$-Proteobacteria, Actinobacteria, and Bacteroides. Among these, three Pseudomonas strains and Rhodobacter sp. possessed genes coding for polyhydroxyalkanoates synthase. Comparative analysis revealed that most of the microorganisms detected by direct molecular analysis were obtained by the traditional culturing method.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.194-199
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• 1995

A portion (7.4 kb) of ribosomal DNA tandem repeat unit from a genome of the mushroom T. matsutake has been cloned. A 1.75 kb EcoRI fragment was cloned first using S. cerevisiae 255 rRNA gene as a probe, and this was then used for further cloning. A chromosomal walking experiment was carried out and the upstream region of the 1.75 kb fragment was cloned using SmaI/BamHI enzyme, the size was estimated to be 5.2 kb in length. Part of the downstream region of the 1.75 kb fragment was also cloned using XbaI/BamHI enzymes. Restriction enzyme maps of three cloned DNA fragments were constructed. Northern hybridization, using total RNA of T. matsutake, and the restriction fragments of three cloned DNAs as probes, revealed that all four ribosomal RNA genes (large subunit[LSU], small subunit [SSU], 5.85 and 5S rRNA genes) are present in the cloned region. The gene organization of the rDNA are regarded as an intergenic spacer [IGS]2 (partial) - SSU rRNA - internal transcribed spacer [ITS]1 - 5.8S rRNA - ITS2 - LSU rRNA - IGS1 -5S rRNA - IG52 (partial).

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.163-164
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• 2000

Vibrio는 새우양식장 및 종묘배양장의 사육수에서 가장 qlsqjsgkrp 출현하며 양식새우의 질병과 직간접적으로 관련을 갖고 있는 주요 병원성 세균류로서 이들 종의 신속한 동정은 질병의 조기진단 및 대책을 위하여 매우 중요하기 때문에 이에 대한 연구가 많이 이루어져 왔으나 일부 Vibrio 종들간의 생리, 화학적 특성이 너무도 유사하여 동정에 많은 어려움을 겪고 있다. (중략)