• Journal of Aquaculture
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• v.9 no.1
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• pp.19-23
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• 1996

Hormonal induction of sex reversal was examined by using sex steroid hormones in serranid fish, Epinephelus septemfasciatus. Young fish were collected from the coastal area of Cheju Island, and reared for 2 years before fish were used for the experiments. Without any hormonal treatment, gonads of fish ($1,000\~2,800$ g in body weight) were occupied by oocytes of the perinucleolus stage and bundles of protogonial cells in the area of germinal epithelium. When the induction of sex reversal was attempted by daily oral administration of $17\alpha$-methyltestosterone (0.5 mg/kg fish) for 90 days, active spermatogenesis was induced, and spermatogonia and spermatocytes and spermatids were appeared in all gonads we examined. However, after daily, oral treatment of $17\beta$-estradiol (0.5 mg/kg fish) to. 50 days with the following injection of human chorionic gonadotrophin ($1,000\~1,500$ IU/kg fish) mature oocytes were not induced in fish gonad.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.753-760
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• 1995

This study was conducted to determine the serum vitellogenin (VTG) concentration changes during the ovulation period in elkhorn sculpin, Alcichthys alcicornis. The results of sepacryl S-300 showed that the molecular weight of VTG could be 380,000. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) analysis may indicate that the purified VTG consists of three subunits with molecular weights of 180,000, 118,000 and 85,000, respectively. Yolk protein purified from the egg extracts was eluted on an equilibrated sephacryl S-300 column, and its molecular weight was estimated 250,000. The precipitation lines of the female serum against the antiserum of the egg extracts were fused completely by immunoelectrophoresis and immunodiffusion analysis. VTG was detected in the serum, and hepatocytes from males injected with $17\beta-estradiol\;(E_2).$ Furthermore, VTG was immunochemically similar to yolk proteins. The concentration of VTG was high before ovulation $(9.80\pm0.81-11.02\pm0.09 mg/ml),$ and then decreased rapidly after ovulation $(less\;than\;6.19\pm0.59 mg/ml).$ This study suggested that VTG was synthesized in the liver by the action of $E_2$ and released to blood, and then incorporated into oocytes.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.355-361
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• 2011

Effects of aluminum (Al) on plasma vitellogenin (VTG), alkaline-labile phosphorus (ALPP), calcium (Ca), glutamate pyruvate transaminase (GPT), the hepatosomatic index (HSI), and hepatic Al concentration were examined in estradiol-$17{\beta}$ ($E_2$)-administered immature rockfish Sebastes schlegeli. Fish were injected intraperitoneally with $E_2$ (5 mg/kg body weight [BW]) and/or Al (0, 0.1, 1, 5, and 10 mg/kg BW) and plasma and liver samples were extracted 7 days later. After sodium dodecyl sulfate polyacrylamide gel electrophoresis, the relative amount of VTG was determined by integrated optical density. VTG accounted for 23.6% of the total proteins in the control group, but this value decreased with increasing Al administration. Al reduced the concentrations of ALPP and Ca in a concentration-dependent manner and significant reduction occurred at Al concentrations greater than 5 mg/kg. The concentration of GPT increased in a concentration-dependent manner in all Al-administered rockfish. The concentrations of Al in the liver also increased, and HSI was decreased, in a concentration-dependent manner. These results suggest that Al inhibits $E_2$-induced VTG production by being toxic to hepatocytes in marine fish.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1445-1451
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• 2007

A sensitive optical waveguide lightmode spectroscopy-based immunosensor was developed to detect vitellogenin in seawater flatfish (Paralichthys olivaceus). For this purpose, anion-exchange column chromatography with DE-52 resin was used to purify flatfish vitellogenin from flatfish serum containing vitellogenin that had been induced using an intraperitoneal $17{\beta}$-estradiol injection. The anti-flatfish vitellogenin antibody used as the biological component of the above immunosensor was prepared using the purified flatfish vitellogenin. The change in the incoupling angle according to the complexation between the flatfish vitellogenin and its antibody, immobilized over an optical grating coupler sensor chip, was measured to calculate the sensor response. The immunosensor was quite specific to flatfish vitellogenin binding, based on no sensor response in the case of bovine serum albumin immobilization. When plotted using double-logarithmic scales, the sensor responses increased linearly in flatfish vitellogenin concentrations of 0.00675-67.5 nM, with a detection limit of 0.0675 nM. The reusability during seven repetitive measurements was reasonably fair for the preliminary screening of flatfish vitellogenin.

• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.47-54
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• 1994

The objective of this study was to produce Korean native calves following transfer of in vitro matured, fertilized and cultured embryos into Holstein cows. The ovaries of Korean native cows or heifers were obtained from an abattoir and kept on 25 to 28$^{\circ}C$ and transported to laboratory within 2 hrs. The oocytes were matured in vitro (IVM) for 24 hrs in TCM-199 supplemented with 35$\mu\textrm{g}$/ml FSH, 10$\mu\textrm{g}$/ml LH, 1$\mu\textrm{g}$/ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% CO2 in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (IVC) with bovine oviductal epithelial cells for 7 to 9 days. Late morulae and blastocysts produced in vitro were nonsurgically transferred to recipient cows by unilaterial. Recipients were monitored for estrus and for pegnancy by rectal plapation in 60 days after embryo transfer. One of them was pregnant to term and produced a female weighing 42.5kg at birth.

• Reproductive and Developmental Biology
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• v.35 no.4
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• pp.519-525
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• 2011

Growth hormone (GH) is obligatory for growth and development. But, there is controversy on the GH effect about reproductive processes of sexual differentiation, pubertal maturation, gonadal steroidogenesis, gametogenesis and ovulation. This study was conducted to investigate the effect of GH on estrus, ovulation and embryo implantation. The results obtained were as follows. GH stimulated to increase estrus rate (p<0.05), pregnancy rate (p<0.05), and total fetus number in mice treated for superovulation. Also, the correlation between GH and steroids, E2 and P4, at peri-estrus stage/ peri-ovulation stage/ peri-implantation stage of the superovulation-induced mice was examined. Consequently, GH co-injected with PMSG especially increased P4 level (p<0.05) at peri-estrus stage of superovulationinduced mice. In conclusion, GH co-treatment in superovulation system boosted the rate of estrus, pregnancy and total fetus by increasing progesterone level at peri-estrus stage of superovulation-induced mice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.882-887
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• 2014

We studied oocyte steroidogenesis in blacktip grouper Epinephelus fasciatus ovarian follicles during vitellogenesis. Vitellogenic oocytes with average diameters of 0.45, 0.48 and 0.50 mm were incubated in vitro in the presence of $[^3H]17{\alpha}$-hydroxyprogesterone as a precursor. The steroid metabolites were analyzed using thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC/MS). The major metabolites in the vitellogenic oocytes were androstenedione ($A_4$), testosterone (T), estradiol-$17{\beta}$ ($E_2$), and estrone ($E_1$). The metabolites of androgen ($A_4$ and T) were higher in the 0.50-mm oocytes than in the 0.45- and 0.48-mm oocytes, while the estrogen metabolites (E2 and E1) were lower in the 0.50-mm oocytes. These results suggest that 0.50-mm oocytes are fully vitellogenic following initiation of the maturation process.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.135-142
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• 1992

This experiment was carried out to establish an effective technique of in vitro maturation of porcine follicular oocytes. Porcine ovaries were collected from an abbatoir and delivered to the laboratory in phosphate buffered saline in an hour. Immatured follicular oocytes were collected from the ovaries and divided into groups by the size of follicles and by the attachment of granulosa cells. The follicular oocytes were cultured in m-KRB solution supplemented with FCS(10%), follicular fluid(10%) or hormones of PMSG(10IU/ml), hCG(10IU/ml ) and $estradiol-17{\beta}(1{\mu}g/ml)$ for 48 hours at $39^{\circ}C$ under an atmosphere of 5% $CO_2$ in air. The results are as follows ; 1. The mean recoveration rate of follicular oocytes was 61.8%. 2. The maturation rate was significantly(p<0.05) higher when the oocytes were collected from large-sized follicles and under good state of granulosa cell attachment. 3. The maturation rate was significantly(p<0.01) promoted when the follicular oocytes were cultured in m-KRB solution supplemented with follicular fluid(74.8%) or hormones and fetal calf serum(70.6%).

• Food Science and Biotechnology
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• v.18 no.3
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• pp.689-693
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• 2009

Germination is well-known to enhance the digestibility, functionality, and palatability of plant seeds. To examine the functionality of germinated-safflower seed (GSS), proliferative and differentiative effects of GSS extract on the mouse calvarial bone cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolinbromide (MTT) assay and alkaline phosphatase activity, respectively. Water extract of GSS increased dose-dependently proliferative and differentiative effects on calvarial bone cell, and its effects were stronger than those of ungerminated-safflower seeds (UGSS) extract. One major component was isolated from GSS extract by a series of purification procedure of solvent fractionation, Diaion HP-20, and Sephadex LH-20 column chromatographies. Its chemical structure was identified as trachelogenin (TC) by nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectral analysis. Trachelogenin showed significant proliferative (125.7%) and differentiative (132.1%) effects on calvarial bone cells at $10^{-8}M$, and its effects were significantly higher than those of $17{\beta}-estradiol\;(E_2)$. TC was found to be a major active compound responsible for high proliferative and differentative effects of the water extract of GSS. Therefore, these results suggest that TC in GSS may be useful as potential therapeutic agent for the prevention and treatment of bone loss.

• Environmental Analysis Health and Toxicology
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• v.17 no.3
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• pp.239-243
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• 2002

Changes of plasma vitellogenin (VTG) and glutamate pyruvate transaminase (GPT) were examined for determining whether hepatocyte was damaged during the process of VTG induction in the juvenile rockfish, Sebastes schlegeli exposed to exogenous estrogen (estradiol-l7$\beta$, E$_2$). Rockfishes were intraperitoneally injected with E$_2$(5 mg/kg B.W.) in 70% ethanol and plasma sampling were extracted at 0, 1, 3, 6, 9, 12, 15 days af-ter E$_2$administration. VTG and GPT were then analyzed by SDS -PAGE and Reitman -Frankel method, respectively. VTG band was detected at a molecular weight position of 175 kDa on Day 3 after E$_2$administration. This band became more distinct at 6 days, but its was gradually thinned with time -course, and not detected at 15 days. GPT was suddenly increased at 1 days after 22 administration and highest GPT was detected at 3 days. However. GPT was gradually decreased with time -course as the change of VTG. These results suggest that the process of VTG induction by exogenous E$_2$damage to hepatocyte, and plasma GPT was temporarily increased in the juvenile rockfish.