• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2003.11a
• /
• pp.159-164
• /
• 2003

Effects of Al on vitellogenin (VTG) and VTG mRNA induction by estradiol-17 $\beta$($E_2$) were examined in primary hepatocyte culture of rainbow trout. Hepatocytes were precultured for 2 days and then E2 ($2{\times}10^{-6}$M) and Al ($10^{-6}-10^{-4}$M) were simultaneously added to the incubation medium. Hepatocytes were cultured for 5 more days. Media and hepatocytes were then analyzed by SDS-PAGE and Northern blotting for VTG and VTG mRNA, respectively. These metal had no appreciable effect on the viability of hepatocytes in culture. However, Al interfered with VTG production and VTG mRNA expression. Al reduced VTG production in a concentration-dependent way and a significant reduction accurred at Al concentrations greater than $5{\times}10^{-5}$M. VTG mRNA expression also decreased with a negative correlation with Al concentration (r＝-0.98). These results suggest that Al inhibit VTG production at the transcriptional level to reduce VTG mRNA expression.

• Development and Reproduction
• /
• v.9 no.2
• /
• pp.135-142
• /
• 2005

Vitellogenins(VTGs) are the precursor of egg-yolk proteins in most oviparous species from invertebrates to vertebrates. In oviparose vertebrates, VTGs are synthesized in the liver and transported through the blood to oocytes. In female fish, concentrations of plasma VTG increase rapidly at onset of vitellogenesis in the normal reproductive cycle. Male fishes also possess the gene for VTG, but plasma concentrations of the protein typically remain small, presumably due to low levels of endogenous estrogens. However, exposure of males to exogenous estrogenic mimics can result elevated. Therefore, the VTG in fish can be used as a useful biomarker for appropriate tools of endocrine disrupting compounds effects. In this studies, we prepared the test methods that can measure the plasma VTG level in the gobies that live in polluted area with mimic estrogen. For the purpose, we purified VTG of floating goby(Chaenogobius annularis) and prepared specific monoclonal and polyclonal antisera to yolk protein, then developed a sandwich competitive ELISA system for measurement of plasma VTG levels. Validation for the ELISA system using monoclonal and polyclonal antibodies against VTG was tested. The absorbance curve of serial dilutions of serum from vitellogenic female was paralleled to the standard curve of VTG, but normal male was not paralleled. The developed sandwich ELISA system was measured for VTG levels in plasma of common goby(Acanthogobius flaviman) and javeline goby(A. hasta) as well as in plasma of floating goby(C. annularis).

• Fisheries and Aquatic Sciences
• /
• v.7 no.3
• /
• pp.99-108
• /
• 2004

Vitellogenin (VTG) was purified from serum of $estradiol-l7{\beta}-treated rockfish$(Sebastes schlegeli) by precipitation with $EDTA-Mg^{2+}$ and ammonium sulfate and two step chromatography (anion exchange chromatography and gel permeation chromatography) was performed on FPLC system. Rockfish VTG (rfVTG) was characterized and its properties were determined. The monomers have apparent, molecular mass of about 188 kDa as indicated by SDS-PAGE. Amino acid composition analysis of rfVTG was similar to VTG from other oviparous teleosts. Cysteine and lysine were present at relatively high level. Leucine was present at relatively lower level than in other species. The N-terminal amino acid sequence was evaluated to identify rfVTG. Western blot analysis using an antibody against the purified VTG showed that the antibody reacted with both plasma of $estradiol-l7{\beta}-treated rockfish$ treated male and purified VTG, whereas there was no reaction with male serum of the control. An ELISA was developed using monoclonal and polyclonal antibodies against rfVTG. The assay range was 3.2 ng/mL and 1,000 ng/mL and the value of the intra and inter assay variations were within $9.7{\%}$ and $11.2{\%}$, respectively. Recovery rate was $96.8{\%}$. The sandwich ELISA could be useful for the detection of VTG and could be good for screening of estrogenic compounds.

• Journal of Aquaculture
• /
• v.9 no.1
• /
• pp.83-92
• /
• 1996

This study was conducted to compare the immunochemical properties of female-specific serum proteins (vitellogenin, VTG) and egg yolk proteins in female fusilier, Caesio diagramma. VTG of fusilier was identified and characterized by using immunochemical analysis. Two types of VTG (VTG1 and VTG2) reacted clearly with antiserum against egg proteins, were confirmed in the serum of mature female. The results of sephacryl S-300 showed that the molecular weights of VTG1 and VTG2 were 560,000 and 410,000, respectively. Yolk proteins, E2 and E3, were isolated from egg extracts, and molecular weights of them were estimated 410,000 and 170,000, respectively. The treatment of $17\beta$-estradiol ($E_2$) to males has induced the synthesis of VTG of which immunological characteristics seems to be similar to the yolk proteins. The results suggest that VTG can be synthesized in the liver by the action of $E_2$ stimulation, and incorporated into the oocytes through the blood circulation. The level of serum $E_2$ was moderately high throughout the spawning period of June. The level of serum VTG was also sustained at high in May and June. The concentration changes of serum $E_2$ and VTG were corelated to the ovarian development in female fusilier. The results indicated that $E_2$ may have some important roles for the vitellogenesis in female fusilier. Also) the VTG can be a precursor protein of yolk not only because it could be synthesized in the liver then incorporated into the oocytes but also because an egg yolk protein had the similiar molecular weights and antigenecity with VTG.

• Fisheries and Aquatic Sciences
• /
• v.4 no.4
• /
• pp.186-191
• /
• 2001

Vitellogenin (VTG) and VTG mRNA induction by $estradiol-17\beta\;(E_2)$ were examined in the primary cultures of hepatocyte in the rainbow trout. Hepatocytes were precultured for 2 days, then $E_2$ was added and cultured for another 5 days. Media and hepatocytes were then analyzed by electrophoresis and Northern blotting for VTG and VTG mRNA, respectively. The hepatocytes were formed a few aggregates within 5 days without further spreading to a monolayer. Cell viability and high DNA content were maintained during the incubation. The hepatocyte culture with E2 induced a weak VTG band at a molecular weight of 175kDa on Day 2 after $E_2$ addition. The relative amount of VTG was expressed in percentage of total protein concentrations. VTG was gradually increased as $1.9\%$ on Day 2, $6.3\%$ on Day 4 and $7.3\%$ on Day 5. VTG mRNA band was detected at about 6.6 kb in the culture with $E_2$ at day 1 of culture. The level of VTG mRNA expression linearly increased with time until Day 5 (r=0.97).

• Proceedings of the Korea Information Processing Society Conference
• /
• 2001.10a
• /
• pp.535-538
• /
• 2001

Since 1990s, many literatures have shown that connectionist models, such as back propagation, recurrent network, and RBF (Radial Basis Function) outperform the traditional models, MA (Moving Average), AR (Auto Regressive), and ARIMA (Auto Regressive Integrated Moving Average) in time series prediction. Neural based approaches to time series prediction require the enough length of historical measurements to generate the enough number of training patterns. The more training patterns, the better the generalization of MLP is. The researches about the schemes of generating artificial training patterns and adding to the original ones have been progressed and gave me the motivation of developing VTG schemes in 1996. Virtual term is an estimated measurement, X(t+0.5) between X(t) and X(t+1), while the given measurements in the series are called actual terms. VTG (Virtual Tern Generation) is the process of estimating of X(t+0.5), and VTG schemes are the techniques for the estimation of virtual terms. In this paper, the alternative VTG schemes to the VTG schemes proposed in 1996 will be proposed and applied to multivariate time series prediction. The VTG schemes proposed in 1996 are called deterministic VTG schemes, while the alternative ones are called stochastic VTG schemes in this paper.

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

• Journal of Aquaculture
• /
• v.11 no.2
• /
• pp.241-248
• /
• 1998

Effects of A23187 on estradiol$-17^{\beta}$-induced vitellogenin (VTG) induction were electrophore-tically examined in primary hepatocyte cultures in rainbow trout. hepatocytes were predultured for 2 days and then estradiol-$17^{\beta}$(E2, $2{\times}10^{-6}$M) and calcium ionophore (A23187, $10^{-7)$~$10^{-5}$ M) were added to the incubation medium. The hepatocytes were cultured for 7 more days. In addition, effects of A23187 on $E_2$-primed VTG production were investigated for 7 days. The addition of A23187 ($10^{-7)$~$10^{-5}$M) to the incubation medium specifically reduced VTG production by hepatocytes in a concentration-dependent way. The addition of A23187 significantly reduced the rate of $E_2$-primed VTG production to 18% of the control (E2 only) on Day 7. However, $E_2$-primed VTG production was reduced to 47% of the control by withdrawal of $E_2$ from the incubation medium. Therefore, these results suggest that intracellualr sequestered calcium could regulate VTG synthesis at the translational and/or post-translational stage.

• Journal of Applied Biological Chemistry
• /
• v.52 no.4
• /
• pp.170-173
• /
• 2009

Vitellogenin (Vtg) is found in the serum of both female and male fish that have been exposed to environmental endocrine disrupters or estrogen hormones, and is used as a biomarker for such contamination. In our current study antibodies raised against the purified flatfish Vtg were tested for their reactivity on immunoblots to flatfish and carp Vtg, and also to a Vtg protein fragment produced in E. coli. Polyclonal antibodies raised against purified flatfish Vtg reacted well with Vtg in the serum of flatfish and carp induced with $17{\beta}$-estradiol, but not with the Vtg protein fragment produced in E. coli.

• The Korean Journal of Zoology
• /
• v.38 no.1
• /
• pp.136-144
• /
• 1995

참개구리의 난모세포에서 난자형성단계에 따른 vitellogenin(VTG)의 이동이 난모세포막에 의하여 조절될 것이란 생각에 기초하여 단계에 따른 VTG 이동량의 변화와 난모세포막의 변경이 VTG 이동에 미치는 영향을 조사하였다 VTG의 이동은 난자형성과정중 특히 초기난모세포에서 가장 활발하였고, 중기 및 말기에는 감소하는 경향을 나타내었다. 반면. bovine serum albumin은 모든 단계의 난오세포에서 이동을 보이지 않았다 이러한 결과로 보아 난자형성과정중 난모세포내로의 VTG 이동은 단계특이적 이고 선택적임을 알 수 있었다. 난모세포막의 막단백질을 trypsin으로 제거시키거나 막단백질의 당잔기를 wheat germ agglutinin(WGh)으로 포화시키든가 혹은 endoglycosidase $\boxDr$로 당잔기를 제거시킨 결과 VTG의 이동이 급격히 억제되었다 이와 같은 결과들은 난모세포의 막단백질이 VTG 이동에서 수용체로 작용한다는 사실을 강하게 암시하였다.