• ALGAE
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• v.24 no.3
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• pp.129-138
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• 2009

DNA-based discrimination of species is a powerful way for morphologically otherwise similar species, like centric diatoms. Here, the author sequenced long-range nuclear ribosomal DNAs, spanning from the 18S to the D5 region of the 28S rDNA, of Stephanodiscus, particularly including a Korean isolate. By comparisons, high DNA similarities were detected from the rDNAs of nine Stephanodiscus (>99.4% in 18S rDNA, >98.0% in 28S rDNA). Their genetic distances, however, were significantly different (Kruskal-Wallis test, p < 0.01) compared to two related genera, namely Cyclotella and Discostella. In addition, genetic distances of 18S rDNAs were significantly different (Student’s t-test, p = 0.000) against those of the 28S rDNAs according to individual genera (Cyclotella, Discostella, and Stephanodiscus). Phylogenetic analyses showed that Stephanodiscus and Discostella showed a sister taxon relationship, and their clade was separated from a cluster of Cyclotella (1.00 PP, 100% BP). This suggests that Stephanodiscus has highly conserved sequences of both 18S and 28S rDNA; however, Stephanodiscus is well-separated from other freshwater centric diatoms, such as Cyclotella and Discostella, at the generic level.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.90-93
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• 2002

The revolution in molecular biology has given us greatly increased ability to obtain and to modify biological resources and to use them for the benefit of all humankind. The sequencing and the associated analysis of gene functions for a growing number of genomes will have an unprecedented effect on the uses of biological resources and the need for access to them. To investigate the diversity of microbial community in swamp, molecular systematic methods were applied. By amplified rDNA restriction analysis (ARDRA) and rDNA partial sequence analysis, $75\%$ of the isolates were known species. In case of uncultured analysis, almost all the selected clones were new species candidate. Especially archea and uncultured bacterial analyses, all clones were new taxon candidates. As for the eukaryotic diversity, several yeast form cultures were isolated from various samples of swamp. Among them, about $60\%$ of the isolates were easily identified. In case of a new species candidate, most strain were included in hymenomycetal yeasts.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.203-213
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• 2006

The spatial patterns of meiobenthic communities in deep-sea sediment were examined. Sediment samples for analyzing of meiobenthic community structure were collected using a remote operated vehicle (ROV), multiple corer TV grab at 20 stations at five sites. In all, 15 meiofauna groups were recorded. Nematodes were the most abundant taxon. Benthic foraminiferans, harpacticoid copepods, polychaetes, and crustacean naupii were also dominant groups at all sites. The total meiofauna density at the study sites varied from 49 to 419 ind./$10cm^2$. The maximum density was recorded at a site located in Challenger Deep in the Mariana trench where simple benthic foraminifera with organic walls flourish. These distinctive taxa seem to be characteristic of the deepest ocean depths. Active hydrothermal sediments contain up to 150 harpacticoid copepods per $10cm^2$ of sediment. In a inactive ridge sediments, devoid of macrofaunal organisms:, the abundance of harpacticoid copepods never exceeded 15 ind./$10cm^2$. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among the three regions; near an active hydrothermal vent, in the deepest ocean depths and at typical deep-sea bed sites.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.472-482
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• 1991

Seasonal distributions of zooplankton were investigated in Asan Bay, Korea. Labidocera euchaeta, Sagitta crassa, Calanus sinicus, Acartia omorii were dominant taxa throughout the year with seasonally varying percent compositions. Bivalve veliger larva (fall), Decapoda larva (spring and summer), and Paracalanus Parvus, Evadne tergestina (summer) were also dominated during contain period. The patterns of time dependent vertical distributions of one major taxon, A. omorii, showed seasonal differences, i.e., it showed the trends of normal vertical migration in winter and reversed vertical migration in spring. At surface layer day time abundances were equal or less than night time abundances in general.

• Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.8.1-8.18
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• 2017

Background: Metallothionein (MT) is a multifunctional protein playing important roles in homeostatic regulation and detoxification of metals. Mollusk species have been considered as useful sentinel platforms for MT-based biomarker approaches, and they have been reported to display an extraordinary structural diversity of MT proteins. However, potential diversity of molluskan MTs has not been fully explored and recent updates have suggested the need of revision of evolutionary hypothesis for molluskan MTs. Results: Based on bioinformatic analysis and phylogenetic evidences, novel divergence mechanisms and paths were hypothesized in both gastropod and bivalve MT groups. Our analyses are suggestive of the taxon- or lineage-specific domain multiplication/duplication from the ancestral or prototypic MT. Diversification and selection of molluskan MTs might be driven by the needs for acquiring metal selectiveness, specialized novel function, and improved capacity of metal detoxification under environmentally stressed conditions. Conclusion: The structural diversity and variations of molluskan MTs are significantly larger than previously understood. Undoubtedly, molluskan MTs have undergone dynamic divergent processes in their evolutionary histories, giving rise to the great diversity of domain structures in extant MT isoforms. Novel evolutionary paths for molluskan MTs newly proposed in this review could shed additional light onto the revision of the hypothesis for evolutionary differentiation of MTs in the molluskan lineage.

• The Plant Pathology Journal
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• v.36 no.2
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• pp.185-191
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• 2020

Streptomyces griseus S4-7, a well-characterized keystone taxon among strawberry microbial communities, shows exceptional disease-preventing ability. The whole-genome sequence, functional genes, and bioactive secondary metabolites of the strain have been described in previous studies. However, proteomics studies of not only the S4-7 strain, but also the Streptomyces genus as a whole, remain limited to date. Therefore, in the present study, we created a proteomics reference map for S. griseus S4-7. Additionally, analysis of differentially expressed proteins was performed against a wblE2 mutant, which was deficient in spore chain development and did not express an antifungal activity-regulatory transcription factor. We believe that our data provide a foundation for further in-depth studies of functional keystone taxa of the phytobiome and elucidation of the mechanisms underlying plant-microbe interactions, especially those involving the Streptomyces genus.

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.350-356
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• 2015

Abeliophyllum distichum is a monotypic taxon of Oleaceae and endemic to Korea. A comprehensive study on embryogeny and fruit and seed coat ontogeny in Abeliophyllum was carried out via microtome and light microscopy. The fertilization occurs during mid– to late April and embryo matures by early July. The embryo development follows the general fashion from globular embryo – transition embryo – heart shaped embryo – torpedo embryo – walking-stick embryo to mature embryo. The pericarp clearly differentiates into three histological zones: exocarp, mesocarp, and endocarp. The young seed comprises 10-12 cells thick seed coat and the mature seed coat comprises an exotesta, 6-8 mesotesta and an endotesta. Any crystals, phenolic-like compounds, idioblasts, and the sclereids are not found in pericarp as well as seed coat. An overall development confirms Solanade type of embryogenesis in Abeliophyllum. The endocarp becomes more prominent in mature fruit and all the layers of endocarp are highly lignified. On the basis of mechanical layer the seed coat is of exotestal type.

• Korean Journal of Plant Taxonomy
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• v.34 no.2
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• pp.119-152
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• 2004

Allium taxa of Korea were taxonomically reviewed, and classified as three subgenera, ten sections, seventeen species, and three varieties. Among these, Korean endemics were recorded as six taxa; A. koreanum, A. taquetii, A. deltoide-fistulosum, A. linearifolium, A. thunbergii var. deltoides, A. thunbergii var. teretafolium. In addition, A. condensatum, A. splendens and A. maximowiczii proved to distribute only in North Korea. Keys to the subgenera, sections, species and infraspecies with descriptions of each taxon were provided.

• Korean Journal of Plant Taxonomy
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• v.45 no.1
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• pp.17-21
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• 2015

A new species belonging to Lycopodiaceae Mirb. Huperzia Bernh. s.l. is described and illustrated: Huperzia jejuensis B.-Y. Sun & J. Lim. H. jejuensis has been considered conspecific with H. integrifolia (Matsuda) B. ${\emptyset}$llg. ex. Z. Satou, but it is clearly distinguished by the characteristics of linear-lanceolate leaves with parallel margins from the base to the mid-part, minute dentate margins from the mid-part to the end of the leaf, and cuspidate gemma apex. Because the habitat of the new species was confined to Jeju Island, 'jejuensis' was chosen as the specific epithet of the scientific name of the new taxon.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.410-414
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• 1992

Numerical identification was carried out for an isolate of Streptomyces strain producing the extracellular p-lactamase inhibitor. Fifty taxonomic unit characters were tested and the data were analyzed numerically using the TAXON program. The isolate was identified to the major cluster 5 of Streptomyces and it was best matched to Streptomyces omiyaensis which is a synonym of Streptomyces exfoliatus. Therefore, it was concluded that the isolate was identified to be a strain (SMF 19) of Streptomyces exjbliatus.