• Polymer(Korea)
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• v.33 no.2
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• pp.118-123
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• 2009

Keratin contains regulatory molecules that can enhance neuronal cell activity. We fabricated keratin/ PLGA films using 0, 10, 20, and 50 wt% of keratin using solvent casting method. We measured the contact angle of each film and cell proliferation was assayed by counting the cells attached on the film. Adhered cell morphology was confirmed by scanning electron microscope. RT-PCR was conducted to evaluate the gene expression of NF, NSE, and S-100, the Schwann cell markers. The keratin content of 20 and 50 wt% provided higher wettability than PLGA. The 20 wt% keratin was better in cell adhesion and proliferation of SCs than other keratin/PLGA films. The phenotypic stability of SC was maintained with the keratin content of 10 and 20 wt%.

• Ocean and Polar Research
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• v.40 no.4
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• pp.213-222
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• 2018

We investigated seasonal variations in the abundance of the adults and the resting eggs of copepods to understand the role of copepod resting eggs for maintaining their population inhabiting the coastal area of Dadaepo, Korea. Adults and resting eggs of copepods were collected bi-monthly with a conical net (45 cm mouth diameter, $330{\mu}m$ mesh size) and van Veen grab ($0.1m^2$ area), respectively, from October 2016 to September 2017. The species of resting eggs were identified using mtCOI gene. The mean abundance of copepods was highest in October ($3686{\pm}1190inds{\cdot}m^{-3}$) and lowest in January ($176{\pm}60inds{\cdot}m^{-3}$) with the dominance of Paracalanus parvus s.l.. Among copepod producing resting eggs, Acartia omorii and Centropages abdominalis were dominant. The mean abundance of resting eggs was the highest in July ($9148{\pm}6787eggs{\cdot}m^{-2}$) and the lowest in October ($530{\pm}348eggs{\cdot}m^{-2}$). Most of the collected resting eggs were identified as A. omorii's. The mean abundances of A. omorii adults and resting eggs were highest in July, and both abundances fluctuated in a similar pattern except in September. In September, A. omorii adults were observed in a state of low abundance, while their resting eggs occurred in a state of high abundance. These results suggest that A. omorii maintain their population by producing a large quantity of resting eggs, particularly diapause eggs, before the seawater temperature rises. These eggs would hatch and be newly recruited to their population when the environmental condition becomes favorable.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1231-1240
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• 2021

Members of the genus Bacillus are known to play an important role in promoting plant growth and protecting plants against phytopathogenic microorganisms. In this study, 21 isolates of Bacillus spp. were obtained from the root micro-ecosystem of Suaeda glauca. Analysis of the 16S rRNA genes indicated that the isolates belong to the species Bacillus amyloliquefaciens, Bacillus velezensis, Bacillus subtilis, Bacillus pumilus, Bacillus aryabhattai and Brevibacterium frigoritolerans. One of the interesting findings of this study is that the four strains B1, B5, B16 and B21 are dominant in rhizosphere soil. Based on gyrA, gyrB, and rpoB gene analyses, B1, B5, and B21 were identified as B. amyloliquefaciens and B16 was identified as B. velezensis. Estimation of antifungal activity showed that the isolate B1 had a significant inhibitory effect on Fusarium verticillioides, B5 and B16 on Colletotrichum capsici (syd.) Butl, and B21 on Rhizoctonia cerealis van der Hoeven. The four strains grew well in medium with 1-10% NaCl, a pH value of 5-8, and promoted the growth of Arabidopsis thaliana. Our results indicate that these strains may be promising agents for the biocontrol and promotion of plant growth and further study of the relevant bacteria will provide a useful reference for the development of microbial resources.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.217-225
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• 2021

The family Platycephalidae is a taxonomic group of economically important demersal flathead fishes that predominantly occupy tropical or temperate estuaries and coastal environments of the Indo-Pacific oceans and the Mediterranean Sea. In this study, we for the first time analyzed the complete mitochondrial genome (mitogenome) of the flathead Platycephalus cultellatus Richardson, 1846 from Vietnam by Next Generation Sequencing method. Its mitogenome was 16,641 bp in total length, comprising 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNA genes. The gene composition and order of the mitogenome were identical to those of typical vertebrates. The phylogenetic trees were reconstructed based on the concatenated nucleotide sequence matrix of 13 PCGs and the partial sequence of a DNA barcoding marker, cox1 in order to determine its molecular phylogenetic position among the order Scorpaeniformes. The phylogenetic result revealed that P. cultellatus formed a monophyletic group with species belonging to the same family and consistently clustered with one nominal species, P. indicus, and two Platycephalus sp. specimens. Besides, the cox1 tree confirmed the taxonomic validity of our specimen by forming a monophyletic clade with its conspecific specimens. The mitogenome of P. cultellatus analyzed in this study will contribute valuable information for further study on taxonomy and phylogeny of flatheads.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.44-53
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• 2023

Background: The genus Panax in the Araliaceae family has been used as traditional medicinal plants worldwide and is known to biosynthesize ginsenosides and phytosterols. However, genetic variation between Panax species has influenced their biosynthetic pathways is not fully understood. Methods: Simultaneous analysis of transcriptomes and metabolomes obtained from adventitious roots of two tetraploid species (Panax ginseng and P. quinquefolius) and two diploid species (P. notoginseng and P. vietnamensis) revealed the diversity of their metabolites and related gene expression profiles. Results: The transcriptome analysis showed that 2,3-OXIDOSQUALENE CYCLASEs (OSCs) involved in phytosterol biosynthesis are upregulated in the diploid species, while the expression of OSCs contributing to ginsenoside biosynthesis is higher in the tetraploid species. In agreement with these results, the contents of dammarenediol-type ginsenosides were higher in the tetraploid species relative to the diploid species. Conclusion: These results suggest that a whole-genome duplication event has influenced the triterpene biosynthesis pathway in tetraploid Panax species during their evolution or ecological adaptation. This study provides a basis for further efforts to explore the genetic variation of the Panax genus.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.401-409
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• 2006

Purpose : Human metapneumovirus(hMPV) is a respiratory viral pathogen that causes a wide spectrum of illnesses, ranging from asymptomatic infection to severe bronchiolitis. The virus has been identified world widely, but so far it has not been published in Korea. Methods : We obtained clinical samples by nasopharyngeal aspiration from 218 children hospitalized due to acute lower respiratory tract infections at Soonchunhyang University Hospital in Cheonan from October, 2004 to April, 2005. We designed specific primers from conserved region of fusion glycoprotein of hMPV. Total RNA was extracted and RT-PCR was performed, and single specific 423 bp product was obtained. The PCR product was confirmed to be fusion glycoprotein RNA by sequencing. Results : We detected hMPV in 15(6.9 percent) of the 218 hospitalized children. The infected children comprised nine boys and six girls; their mean age was 2.8 years(5 mo-12 yrs) and they were diagnosed with pneumonia(60 percent), bronchiolitis(33.3 percent), croup(6.6 percent). The number of cases of detected hMPV in Korea increased dramatically during the period from March to May 2005. Conclusion : hMPV is circulating in Korean children and is associated with respiratory tract infection. Additional studies are required to define the epidemiology and the extent of diseases in the general population caused by hMPV.