• Journal of the korean society of oceanography
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• v.35 no.3
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• pp.158-160
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• 2000

The relativity of four isolates of C. polykrikoides was determined by comparative sequence analysis based on direct sequencing of PCR amplified ribosomal DNA (the internal transcribed spacer region and the 5.8S rDNA). Sequence comparisons indicated that four isolates had the same nucleotide sites in the ITS regions, as well as a total of 585 nucleotide length and 100% homology. The molecular data revealed that C. polykrikoides in Korean coastal waters show no genetical difference.

• The Korean Journal of Mycology
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• v.49 no.4
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• pp.425-431
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• 2021

New species of arbuscular mycorrhizal fungi (Glomeromycota), Acaulospora jejuensis, was isolated from rhizosphere soils of Miscanthus sinensis in the grassland in Jeju Island of Korea. The species was identified using the morphological characteristics of the spores and the molecular phylogenetic analysis using partial DNA sequences from small subunit rDNA (SSU), internal transcribed spacer (ITS), and large subunit rDNA (LSU). Phylogenetic analysis placed the fungal species in a distinct clade within genus Acaulospora. Also, the species exhibited the morphological characteristics distinct from the other members of the genus. Therefore, Acaulospora jejuensis was described as a novel species from Korea.

• Korean Journal of Plant Taxonomy
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• v.43 no.1
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• pp.63-68
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• 2013

ITS DNA sequences of two variants of Pinus spp. having single fasciculate leaf or two to three fasciculate leaves within an individual were analysed in order to determine their origin. Also, the same DNA locus of P. densiflora, P. rigida and P. koraiensis, distributed at the same region together with the OTUs having leaf variations, were analysed to compare with each other. Aligned sequences including ITS1, 5.8S and ITS2 were 580~584 bp in length. The 5.8S region was well conserved among all the OTUs we tested except for P. koraiensis, which has two nucleotide substitutions. The partial ITS1 region upstream of the 5.8S region showed relatively high sequence diversity compare to the ITS2 and has 181~185 bp in length. In this region, the sequences of the two variants were identical to that of P. densiflora. The ITS2 has identical for all OTUs in length and the two variants also have same sequences compare to that of P. densiflora. These two variants and samples of P. densiflora were grouped together in the UPGMA tree with 100% similarity level. The result strongly suggest that these two variants were originated from P. densiflora.

• Journal of Life Science
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• v.18 no.4
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• pp.447-453
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• 2008

Zinc is an essential trace element in Human Being. Highly zinc containing yeast strain isolated from the tropical fruit, rambutan and the zinc concentration in this yeast strain was 306 ppm (30.6 mg%)per dry matter basis. This strain was found to be a rounded type, normal size, and multi-polar budding. Phylogenetic analysis using the ITS1-5.85 rDNA sequences from isolated strain is most similar to yeast Saccharomyces cerevisiae at the level of nucleotide sequence identity at 99%. This strain was produced alcohol by about 12% using fully colonized koji-rice with Aspergillus oryzae. In conclusion, the isolated strain was found to be closely related to the S. cerevisiae based on its morphological and physiological properties, and alcohol fermentation. The phylogenetic analysis of strain FF-10 using ITS 5.8S rDNA sequence data also supported the closely related to the S. cerevisiae. Accordingly, the isolated yeast was named as S. cerevisiae FF-10. Further studies on the best culture conditions for zinc production from zinc-enriched S. cerevisiae FF-10 are under investigation.

• Korean Journal of Microbiology
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• v.28 no.2
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• pp.109-113
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• 1990

The mutagenesis-enhancing plasmid pKM101 and its mutant pSL4 were introduced into Escherichia coli B/r strains possessing different DNA repair capacities ($phr^{-}, recA^{-}, uvrA^{-}, uvrB^{-}$) and determined the protection effect and mutagenecity for UV and MNNG. The mutability and protection effect of plasmid pKM101 and pSL4 were affected by different DNA repair capacity. The mutagenecity and resistance of two plasmids were increased against UV and MNNG, and plasmid pSL4 had a higher effect than pKM101. We suggest that the functional differences between pKM101 and pSL4 is due to the variety of mutator gene.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.335-340
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• 2006

A large number of toxicological substances and pharmacological and physical agents can cause reproductive intervention at the cellular and molecular level. The present study was designed to assess the effect of mercury ($HgCl_2$) at 50 to $550{\mu}M$ concentration ranges, in vitro, on the sperm membrane and DNA integrity, viability, and acrosomal status of normal bull spermatozoa. The samples were processed for sperm analyses using semen-diluting fluid (PBS, pH 7.2). We recorded a sharp increase in the lipid peroxidation/LPO rate; the highest was at $550{\mu}M$ mercury concentration, indicating a deleterious effect of mercury on the sperm membrane intactness. There was also a strong negative correlation between LPO rate and % viable spermatozoa (R = 0.987, p<0.001). Data obtained from a comet assay technique revealed that mercury is capable of inducing DNA breaks in the sperm nuclei. Interestingly, 92% of DNA breaks were double-stranded. The correlation between LPO rate and % DNA breaks was 0.984. Performing the gelatin test indicates that mercury is able to alter the integrity of acrosomal membranes showing an abnormal acrosome reaction. In this regard, a strong link was found between LPO rate and % halos (R = 0.990, p<0.001). Collectively, mercury proved to be a potent oxidant in the category of environmental factors affecting bull spermatozoa. Hence, considering the wide spread use of mercury and its compounds, these metals should be regarded with more concern.

• Journal of Microbiology
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• v.33 no.2
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• pp.136-141
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• 1995

From a cluster of structural rRNA genes which has previsouly been cloned (Hwang and Kim, in submission; J. Microbiol. Biotechnol.), a 1.0-kb Eco RI fragment of DNA which shows significant homology to the 25S and rRNA s of Tricholoma matsutake was used for sequence analysis. Nucleotide sequence was bidirectionally determined using delection series of the DNA fragment. Comparing the resultant 1016-base sequence with sequences in the database, both the 3'end of 25S-rRNA gene and 5S rRNA gene were searched. The 5S rRNA gene is 118-bp in length and is located 158-bp downstream of 3'end of the 25S rRNA gene. IGSI and IGS2 (partial) sequences are also contained in the fragment. Multiple alignment of the 5S rRNA sequences was carried out with 5S rRNA sequences from some members of the subdivision Basidiomycotina obtained from the database. Polygenetic analysis with distance matrix established by Kimura's 2-parameter method and phylogenetic tree by UPGMA method proposed that T. matsutake is closely related to efibulobasidium allbescens. Secondary structure of 5S rRNA was also hypothesized to show similar topology with its generally accepted eukaryotic counterpart.

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.97.2-97.2
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• 2006

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.112-119
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• 2010

Pleurotus spp. have been used for edible and medicinal purposes in Asian countries for a long time. The fruiting bodies of the Pleurotus ostreatus, Pleurotus citrinopileatus and Pleurotus salmoneostramineus contained many physiologically beneficial substances for human health. Therefore, it is necessary to study the genetic diversity of Pleurotus mushroom cultivars commercially cultivated in Korea. Eleven strains of Pleurotus spp. were collected from different geographical regions in South-East Asia and ITS regions of rDNA and RAPD of genomic DNA were analyzed. The size of the ITS1 and ITS2 regions of rDNA from the different strains varied from 167 to 254 bp and 156 to 213 bp, respectively. The sequence of ITS1 was more variable than that of ITS2, and the 5.8S sequences were identical. A phylogenetic tree based on the ITS region sequences indicated that selected strains could be classified into 4 clusters. Eleven Pleurotus species were also analyzed by RAPD with 20 arbitrary primers. Ten of these primers were efficiently amplified the genomic DNA. The number of amplified bands varied with the primers and strains, with polymorphic fragments in the range from 0.1 to 2.0kb. The results revealed that genetic diversity of selected strains of P. ostreatus, P. citrinopileatus and P. salmoneostramineus is low.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.150-155
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• 2005

The ethanolic extract of chestnut (Castanea crenata S. et Z., Fagaceae) inner shell (CISE) and one of its components, ellagic acid (EA), were evaluated for their protective effects against 1, 1-diphenyl-2-picryl hydrazine (DPPH) free radical generation and hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line. CISE and EA were shown to possess the free radical scavenging effect against DPPH radical generation, significantly. They were also found to strongly inhibit hydrogen peroxide-induced DNA damage from Chinese hamster lung (CHL) cell, assessed by single cell gel electrophoresis assay and 8-hydroxy -2'-deoxy guanosine (8-OH-2'dG) assay. Furthermore, topical application of CISE [$12.5\%$(w/w) cream] and ellagic acid [$1.0\%$(w/w) cream] for 14 days potently inhibited malondialdehyde (MDA) formation of mouse dorsal skin (a marker of lipid peroxidation) induced by ultraviolet B exposure. Therefore, CISE and its component, ellagic acid, may be the useful natural antioxidants by scavenging free radicals, inhibition of lipid peroxidation and protecting oxidative DNA damage when topically applied.