• Journal of Microbiology and Biotechnology
• /
• 제15권4호
• /
• pp.838-843
• /
• 2005

Brain-derived neurotrophic factor (BDNF) is a small secretory protein and a member of the nerve growth factor (NGF) gene family. We cloned the flounder BDNF gene from a flounder brain cDNA library. The nucleotide sequence of the cloned gene showed an open reading frame (ORF) consisting of 810 bp, corresponding to 269 amino acid residues. The tissue distribution of flounder BDNF was determined by reverse transcription-polymerase chain reaction (RT-PCR) in brain, embryo, and muscle tissues. To express fBDNF using a eukaryotic expression system, we constructed the vector mpCTV-BDNF containing the fBDNF gene and transformed this vector into Chlorella ellipsoidea. Stable integration of introduced DNA was confirmed by PCR analysis of genomic DNA, and mRNA expression in C. ellipsoidae was confirmed by RT-PCR analysis.

• Fisheries and Aquatic Sciences
• /
• 제5권4호
• /
• pp.258-262
• /
• 2002

Effects of Escherichia coli genomic DNA on the production of phagocyte activating supernatants by the head kidney leucocytes isolated from olive flounder (Paralichthys olivaceus) were investigated. Phagocyte activating activity of the supernatants was estimated by. measuring reactive oxygen species (ROS) production in target head kidney phagocytes. All supernatants from olive flounder head kidney leucocytes-stimulated with E. coli DNA induced significantly (P<0.01) higher ROS production from target pagocytes than the unstimulated control supernatant. Maximum enhancement of chemiluminescent response was observed $5.0-10.0{\mu}g\;mL^{-1}$ of bacterial DNA while the increment ability was decreased significantly (P<0.01) at the concentration of $20.0{\mu}mL^{-1}$. The results demonstrate that olive flounder head-kidney leucocytes stimulated with bacterial DNA release a soluble phagocyte activating cytokines capable of enhancing the respiratory burst activity from target phagocytes.

• 한국어병학회지
• /
• 제30권1호
• /
• pp.67-70
• /
• 2017

Pseudomonas is currently causing increasing mortality in farmed olive flounder in Jeju Island. It was previously reported that P. anguilliseptica is the pathogen causing the mortality. It is not known whether other sub-species are involved or not. In this study, P. fluorescens was identified from diseased olive flounder by a PCR-based diagnosis. Based on genomic sequencing and BLAST analysis, 5 out of 6 samples were closer with P. fluorescens than P. anguilliseptica. Our finding suggests that P. fluorescens may be the dominant species causing the disease in farmed olive flounder in Jeju Island, South Korea.

• 한국양식학회지
• /
• 제10권4호
• /
• pp.409-415
• /
• 1997

The carp $\beta$-actin regulatory sequences and RSV/LTR promoter were tested whether they are functinal to express linked structure gene (chloramphenicol acetyltransferas, CAT) in olive flounder (Paralichthys olivaceus) by determining the patterns of gene expression following intramuscular in vivo direct injection. The injection experiments with various concentrations of both pRSVCAT and pFV4CAT clearly revealed the effectiveness of DNA dosage on expression of CAT. The increase of CAT activity was linear in both plasmids, and maximal CAT activity was obtained with 100 ug of pFV4CAT injection. The amounts of CAT expression with pFV4CAT-injected fist were higher than those with pRSVCAT-injected fish. CAT activity was readily detectable as early as one day after injection, slightly increased at day 2, and declined over time. Most amount of DNA intramuscularly injected into olive flounder muscles persisted extrachromosomally without showing any integrated or replicated form in vivo.

• 한국발생생물학회지:발생과생식
• /
• 제18권4호
• /
• pp.275-286
• /
• 2014

To successful molecular breeding, identification and functional characterization of breeding related genes and development of molecular breeding techniques using DNA markers are essential. Although the development of a useful marker is difficult in the aspect of time, cost and effort, many markers are being developed to be used in molecular breeding and developed markers have been used in many fields. Single nucleotide polymorphisms (SNPs) markers were widely used for genomic research and breeding, but has hardly been validated for screening functional genes in olive flounder. We identified single nucleotide polymorphisms (SNPs) from expressed sequence tag (EST) database in olive flounder; out of a total 4,327 ESTs, 693 contigs and 514 SNPs were detected in total EST, and these substitutions include 297 transitions and 217 transversions. As a result, 144 SNP markers were developed on the basis of 514 SNP to selection of useful gene region, and then applied to each of eight wild and culture olive flounder (total 16 samples). In our experimental result, only 32 markers had detected polymorphism in sample, also identified 21 transitions and 11 transversions, whereas indel was not detected in polymorphic SNPs. Heterozygosity of wild and cultured olive flounder using the 32 SNP markers is 0.34 and 0.29, respectively. In conclusion, we identified SNP and polymorphism in olive flounder using newly designed marker, it supports that developed markers are suitable for SNP detection and diversity analysis in olive flounder. The outcome of this study can be basic data for researches for immunity gene and characteristic with SNP.

• Fisheries and Aquatic Sciences
• /
• 제10권1호
• /
• pp.1-7
• /
• 2007

The induction of cellular and humoral immunity and cytokine gene expression by synthetic CpG oligodexoynucleotides (CpG-ODNs) has not been investigated systematically in olive flounder Paralichthys olivaceus in vivo. We optimized the proper concentration of CpG-ODNs using an in vitro assay for the superoxide anion $(O_2^-)$. CpG-ODNs induced $O_2^-$ and nitric oxide (NO) production, lysozyme activity, and the proinflammatory cytokine gene expression of $IL-1{\beta}$ and $TNF-{\alpha}$ in olive flounder significantly in vivo, whereas non-CpG-ODNs did not produce these effects or produced them to a lesser extent. This implied that CpG-ODNs could stimulate cellular and humoral immunity and cytokine gene expression in olive flounder. This is the first evidence of NO production and the first study on the mRNA expression of the proinflammatory cytokine genes $IL-1{\beta}$ and $TNF-{\alpha}$ in olive flounder in response to CpG-ODNs. Comparison of the variation in NO production and lysozyme activity to that of other studies led us to postulate that a group-specific difference exists in the immune responses of olive flounder against CpG-ODNs. Furthermore, the detailed immunostimulatory spectrum of CpG-ODNs in olive flounder could be a useful index with which to analyze the effect of CpG-ODNs against the challenge test prior to field applications.

• 한국어병학회지
• /
• 제35권2호
• /
• pp.225-230
• /
• 2022

Viral hemorrhagic septicemia (VHS) is one of the most serious viral diseases affecting farmed olive flounder (Paralichthys olivaceus) in Asian countries. VHS, caused by viral hemorrhagic septicemia virus (VHSV), occurs in over 80 different cultured and wild fish species worldwide. Our previous study demonstrated that VHSV infection can be restricted by adjusting the water temperature to over 17℃ from the host optima. We confirmed that the effective VHSV immersion vaccine treatment was a tissue culture infection dose (TCID) of 10^5.5 TCID₅₀/mL at 17℃. However, the safety of live VHSV immersion vaccines remains unclear. The objectives of this study were to 1) demonstrate the safety of the live VHSV immersion vaccine under co-habitant conditions and 2) estimate the pathogenicity of VHSV in live VHSV-vaccinated flounder at 10℃. No mortality was observed in olive flounder treated with the live VHSV immersion vaccine, and the vaccinated flounder challenged with VHSV did not transfer VHSV to naïve fish at 10℃ through cohabitation. VHSV titration was below the detection limit (< 1.3 log TCID₅₀/mL) in live VHSV immersion vaccine-treated flounder challenged with VHSV at 10℃. This study demonstrated that flounder treated with the live VHSV immersion vaccine were resistant to VHSV infection, and the live vaccine was also safe for naïve fish even at a water temperature known to be VHS infectious.

• Fisheries and Aquatic Sciences
• /
• 제5권2호
• /
• pp.103-107
• /
• 2002

A 6-week feeding trial was conducted to investigate the effects of six different dietary animal protein sources on growth and body composition of olive flounder, Paralichthys olivaceus in recirculating system. White fish meal (WFM), flounder muscle (FLM), carp muscle (CM), blood meal (BM), squid liver powder (SLP) and casein (CA) were used as the main animal protein sources in the six experimental diets. Fish averaging $2.9\pm0.03g$ $(mean\pm SD)$ were distributed to each aquarium as a group of 15 fish and were fed one of the six experimental diets to each treatment of triplicate groups. After 6-week of the feeding trial, fish fed white fish meal (WFM) and flounder muscle (FLM) diets showed a significant higher weight gain $(WG\%)$ (P<0.05) than those of fish fed the CM, BM, SLP and CA diets. Fish fed BM diet showed the lowest WG among all the dietary treatments. Feed conversion ratio (FCR) and protein efficiency ratio (PER) showed the similar trend as WG. Hematocrit and hemoglobin were not affected by the dietary treatments. Fish fed the FLM and CM diets showed significant higher survival rate than those of fish fed BM diets, and there was no significant difference in survival of fish fed WFM, FLM, CM, SLP and CA diets. These results indicated that WFM and FLM are the best dietary protein sources tested in olive flounder.

• 한국해양바이오학회지
• /
• 제10권1호
• /
• pp.1-8
• /
• 2018

The objective of this study was to purify and characterize the ${\beta}-secretase$ inhibitor from enzymatic hydrolysates of blackfin flounder muscle, for development of a novel anti-dementia agent that may be used in the drug or functional food industries. ${\beta}-secretase$ inhibitory peptide was purified from various enzymatic hydrolysates of blackfin flounder muscle. Among six enzymatic hydrolysates, the Alcalase hydrolysate revealed highest ${\beta}-secretase$ inhibitory activity. Consecutive purification of the blackfin flounder muscle hydrolysate using Sephadex G-25 column chromatography and octadecylsilane C18 reversed phase HPLC techniques were used to isolate a potent ${\beta}-secretase$ inhibitory peptide composed of 5 amino acids, Leu-Thr-Gln-Asp-Trp (MW: 526.7 Da). The $IC_{50}$ value of purified ${\beta}-secretase$ inhibitory peptide was $126.93{\mu}M$. Results of this study suggest that peptides derived from blackfin flounder muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• Fisheries and Aquatic Sciences
• /
• 제16권2호
• /
• pp.93-99
• /
• 2013

In 2009, a systemic megalocytivirus infection associated with high mortality was detected for the first time in cultured starry flounder Platichthys stellatus in Korea. Diseased starry flounder had pale bodies and gill coloring and enlarged spleens. Histopathological examinations revealed basophilic enlarged cells in various organs of diseased starry flounder. Polymerase chain reaction (PCR) was performed on tissue samples using three published primer sets developed for the red sea bream iridovirus. PCR products were detected for all primer sets, except 1-F/1-R, which are registered by the World Organization for Animal Health (OIE). The part of the gene corresponding to the full open reading frame encoding the viral major capsid protein (MCP) was amplified by PCR. PCR products of approximately 1,581 bp were cloned, and the nucleotide sequences were analyzed phylogenetically. The MCP gene of the starry flounder iridovirus, designated SFIV0909, was identical to that of the turbot reddish body iridovirus (AB166788).