• Journal of Embryo Transfer
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• v.31 no.4
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• pp.355-365
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• 2016

The cryopreservation of sperm has become the subject of research for successful artificial insemination technologies. Antifreeze proteins (AFPs), one of the factors necessary for effective cryopreservation, are derived from certain Antarctic organisms. These proteins decrease the freezing point of water within these organisms to below the temperature of the surrounding seawater to protect the organism from cold shock. Accordingly, a recent study found that AFPs can increase the motility and viability of spermatozoa during cryopreservation. To evaluate this relationship, we performed cryopreservation of boar sperm with AFPs produced in the Arctic yeast Leucosporidium sp. AFP expression system at four concentrations (0, 0.01, 0.1, and $1{\mu}g/ml$) and evaluated motility using computer assisted sperm analysis. DNA damage to boar spermatozoa was measured by the comet assay, and sperm membrane integrity and acrosome integrity were evaluated by flow cytometry. The results showed that motility was positively affected by the addition of AFP at each concentration except $1{\mu}g/ml$ (p<0.001). Although cryopreservation with AFP decreased the viability of the boar sperm using, the tail DNA analyses showed that there was no significant difference between the control and the addition of 0.1 or $0.01{\mu}g/ml$ AFP. In addition, the percentage of live sperm with intact acrosomes showed the least significant difference between the control and $0.1{\mu}g/ml$ AFP (p<0.05), but increased with $1{\mu}g/ml$ AFP (p<0.001). Our results indicate that the addition of AFP during boar sperm cryopreservation can improve viability and acrosome integrity after thawing.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.121-126
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• 1999

Calli were induced from the petiole explants of Pimpinella brachycarpa on MS medium supplemented with 0.5 mg/L 2,4-D and 0.1 mg/L BA after four weeks of culture. Compact clusters of small and dense cells among these calli were selected and suspension-cultured as the source of embryogenic calli. When transferred to MS medium with 0.1 mg/L NAA, the suspension-cultured cells grew to embryogenic callus. Somatic embryos derived from these embryogenic calli developed into plantlets. The cDNA library was constructed in the embryogenic callus and in order to screen the cDNA library, these cDNAs were plated at a density 1.5 $\times$ 10^5 plaques per 15 cm petridish. Among 19 clones showing preferential hybridization with petiole HD-Zip gene, five clones were obtained after second screening. Four clones among them, were highly homologous to P. brachycarpa shoot-tip Phz4 gene, but one clone, Phc5 was about 1.5 kb which has an extra 163 bp to 5' upstream of Phz4. The Phc5 was 1,531 bp containing poly A tails of 18 bases. ATG start codon for Phc5, was located at position 284 with an open reading frame of 906 by which encodes a polypeptide of 302 amino acids. The Phc5 protein revealed that the polypeptides between 135 and 195 contain a homeodomain as the `leucine zipper' motif.

• Animal Systematics, Evolution and Diversity
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• v.36 no.3
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• pp.240-250
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• 2020

Member of the genus Tobrilus Andrássy, 1959, which belongs to Tobrilidae Filipjev, 1918, are known as free-living nematodes in freshwater habitat. This genus was previously unknown from Korea. Five Tobrilus species are here reported for the first time from Korea: Tobrilus aberrans (Schneider, 1925), Tobrilus diversipapillatus (Daday, 1905), Tobrilus gracilis (Bastian, 1865), Tobrilus longus (Leidy, 1851), and Tobrilus wesenbergi (Micoletzky, 1925). Specimens were collected from sediments of the Nakdong River in Korea. Morphological characters and measurements of the specimens generally agree with the original descriptions of Tobrilus species, except for some differences that can be attributed to intraspecific variation among populations(e.g., nerve ring position [% pharynx] and reproductive length). Each species can be distinguished from other members of the genus by specific characters (e.g., cephalic setae length and position, buccal cavity and pocket shape, vulva position, degree of development of reproductive system, and tail length and shape). Here, five species in the genus Tobrilus are fully redescribed and illustrated using optical microscopy images. DNA barcode sequence information (the D2-D3 region of 28S rDNA) is also provided for molecular species identification.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.402-406
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• 2005

Lipomyces starkeyi produces a novel glucanhydrolase containing endo-dextranase and ${\alpha}-amylase$ activities. A cDNA from L. starkeyi encoding a dextranase was isolated and characterized. The 2,052 kb cDNA fragment (lsd1) carrying dextranase gene showed one open reading frame (ORF) composed of 1,824 bp flanked by a 41 bp 5'-UTR and a 184 bp 3'-UTR including a poly(A) tail of 27 bp. The ORF encodes for a 608 amino acid with a predicted molecular mass of 67.6 kDa. There was 77% deduced amino acid sequence identity between the LSD1 dextranase and the dextranase from Penicillium minioluteum. The primary structure of the dextranase from L. starkeyi has distant similarity with enzymes belonging to glycosyl hydrolase family 49. The lsd1 protein was expressed in the Saccharmyces cerevisiae under control of GAL1 promoter and active dextranase was produced.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.149-155
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• 2011

The objective of this study was to evaluate the antioxidant and antigenotoxic activities of sansuyu fruit (Corni fructus, CF) at temperatures of $25^{\circ}C$, $50^{\circ}C$, and $90^{\circ}C$ using a water extraction method. Total phenolic content (TPC), DPPH radical-scavenging activity (RSA), and superoxide dismutase (SOD)-like activity, and ORAC (Oxygen radical absorbance capacity) values were determined. Also the antigenotoxicity of CF was determined by measuring inhibitory effects of $H_2O_2$ induced DNA damage in human leukocytes using the comet assay. The TPC in the CF extracts was 4.2, 4.6, and 5.5 g/100 g GAE in $25^{\circ}C$, $50^{\circ}C$, and $90^{\circ}C$, respectively. The DPPH RSA of the CF extracts increased in a dose-dependent manner over the range of $50\sim1000\;{\mu}g$/mL in all temperatures and the $SC_{50}$ of DPPH RSA of the CF extracts were not significantly different at different extraction temperatures. The $SC_{50}$ of SOD-like was the highest in CF extracted at $25^{\circ}C$ (1.1 mg/mL) followed by $90^{\circ}C$ (1.2 mg/mL) and $50^{\circ}C$ (1.3 mg/mL). The ORAC values of the CF extracts were not significantly different in low concentration ($10\;{\mu}M$/mL) and was in order of $25^{\circ}C$ ($5.7\;{\mu}M$ TE)< $90^{\circ}C$ ($6.2\;{\mu}M$ TE)< $50^{\circ}C$ ($8.5\;{\mu}M$ TE) in high concentration ($50\;{\mu}M$/mL). $200\;{\mu}M$ $H_2O_2$ induced DNA damages in human leukocytes were significantly reduced by the pretreatment with the CF extracts. These results suggest that sansuyu fruit (Corni fructus) can be used as a natural source for antioxidant activities and as antigenotoxic agents regardless of the water extraction temperature.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.81-85
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• 2003

In round numbers the 100 strains of entomopathogenic nematodes were isolated through the investigation of cultivated including the ginseng forming cultivated and forest soil samples by silkworm trap. The 28 strains of nematodes were selected among the isolated entomopathogenic nematodes that were confirmed the pathogenicity against Holotrichia morosa, Hoiotrichia diomphalia and Ectinus sericeus, the pest of korean ginseng and silkworm. Pathogenicity of the 2025, 2027, 2028, 2034, 2039 and 2057 strains was excellent. Selected entomopathogenic nematodes are classified of two species by morphologiacl and molecular studies, which were Sterinernma carpocapsae sp. and Diplogaster lethier sp.. Diagnostic characters include body length, lateral field pattern, tail shape and so on. The DNA sequences of the ITS region of rDNA shows similar to S. carpocapsae and .D. lethier. Isolated entomopathogenic nematodes were demonstrates that are quite within the realms of possibility for biological control agents of the pests of Korean Ginseng.

• Journal of Society of Preventive Korean Medicine
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• v.14 no.2
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• pp.1-12
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• 2010

The individual differences in disease development and susceptibility have been researched primarily on the subject of genes, environment or the interaction between genes and the environment respectively. However, there have been limitations in explaining complex diseases, and the differences in health and diseases in monozygotic and dizygotic twins. Fortunately, thanks to active research on the relationship between genes and the environment, and epigenetics, there has been much progress in the understanding of body's reactions and changes. Epigenetics is referred to as a study of gene expression through the interactions of DNA methylation, chromatin's histone and the change of structure in tail, RNA editing without any change in DNA sequence. In this paper, we introduce the basic concepts and mechanisms of epigenetics. The result of the epigenetics is heritable ; can regulate gene expressions ; is reversible ; and has many variable forms depending on cell types. The influences of epigenetics occur throughout life, but it is mainly determined in utero during early pregnancies. Diseases occur or the risk rises if these influences continue after birth until adult life when problems occur in excess/lack of nutrition, environmental plasticity, or already inputted data. Therefore, there is a need for change and innovation, especially in interest and investment in health education for young women near pregnancies and correct treatment of epigenetic-related diseases.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.268-275
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• 2004

To investigate the potential application of the single-cell gel electrophoresis (SCGE) assay to carp as an aquatic pollution monitoring technique, gill, liver, and blood cells were isolated from carp exposed to a direct-acting mutagen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), or indirect mutagen, $benzo[\alpha]pyrene$ $(B[\alpha]P)$, then the DNA strand breakage was analyzed using the assay. Based on testing 5 different cell isolation methods and 6 electrophoretic conditions, the optimized assay conditions were found to be cell isolation by filter pressing and electrophoresis at a lower voltage and longer running time (at 0.4 V/cm for 40 min). In preliminary experiments, gill and liver cells isolated from carp exposed to MNNG in vitro exhibited DNA damage signals even with 0.5 ppb exposure, which is a much higher dose than previously reported. In the gill cells isolated from carp exposed to 0.01-0.5 ppm MNNG in vivo, significant dose-and time-dependent increases were observed in the tail for 4 days. As such, the linear correlation between the relative damage index (RDI) values and time for each dose based on the initial 48-h exposure appeared to provide effective criteria for the genotoxicity monitoring of direct-acting mutagenic pollution. In contrast, the in vivo exposure of carp to 0.25-1.0 ppm of $B[\alpha]P$ for 7 days resulted in dose-and time-dependent responses in the liver cells, in which 24-h delayed responses for metabolizing activation and gradual repair after 48 h were also observed. Thus, the negative-sloped linear correlation between the RDI and time at each dose based on the initial 48 h appeared to provide more effective criteria for the genotoxicity monitoring of indirect mutagenic pollution.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.234-241
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• 2008

Agrobacterum tumefaciens-mediated transformation (ATMT) is becoming an effective system as an insertional mutagenesis tool in filamentous fungi. We developed and optimized ATMT for two Colletotrichum species, C. falcatum and C. acutatum, which are the causal agents of sugarcane red rot and pepper anthracnose, respectively. A. tumefaciens strain SK1044, carrying a hygromycin phosphotransferase gene (hph) and a green fluorescent protein (GFP) gene, was used to transform the conidia of these two Colletotrichum species. Transformation efficiency was correlated with co-cultivation time and bacterial cell concentration and was higher in C. falcatum than in C. acutatum. Southern blot analysis indicated that about 65% of the transformants had a single copy of the T-DNA in both C. falcatum and C. acutatum and that T-DNA integrated randomly in both fungal genomes. T-DNA insertions were identified in transformants through thermal asymmetrical interlaced PCR (TAIL-PCR) followed by sequencing. Our results suggested that ATMT can be used as a molecular tool to identify and characterize pathogenicity-related genes in these two economically important Colletotrichum species.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.63-77
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• 2021

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein's solution, Hank's balanced salt solution, marine fish Ringer's solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below -10℃/min. The thawing temperature of 45℃ was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p < 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.