• Environmental Analysis Health and Toxicology
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• v.16 no.1
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• pp.29-34
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• 2001

The estrogenic potency of di -2-ethylhexyl phthalate (DEHP) using reverse transcriptase-PCR respouse of liver vitellogenin mRNA in male African clawed frog (Xenopus laevis) was studied. Male frogs were injected with DEHP at dose of 300$\mu\textrm{g}$/kg and 300 mg/kg body weight through the dorsal lymph sac. After 4 days, using suitable pair of RT-PCR primers, vitellogenin mRNA induction in the liver was measured and DEHP showed vitellogenin mRNA induction in only the group treated with 300 mg/kg. Any significant histological abnormalities by the exposure of DEHP was not shown in both testis and liver.

• Toxicological Research
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• v.17 no.3
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• pp.181-186
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• 2001

The estrogenic potency of bisphenol A using reverse trancriptase-PCR response of liver vitellogenin mRNA in male carp was studied. For this, six combination of primers which were synthesized on the basis of cDNA consensus region of various species, were evaluated and one pair of primers was selected as the best to show 286 bp size-transcript. By using the selected primers, vitellogenin mRNA induction in carp treated with bisphenol A was measured and the chemical showed dose-and time-dependent Induction response. From this result, it was concluded that RT-PCR technique wing the selected primers in this study can be wed to monitor the estrogenic effects exerted In carp living in Korean freshwater.

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

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.197-204
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• 2001

Endocrine disruption in crucian carp (Carassius auratus) living in the branch of Han River were examined. Vitellogenin level in plasma was measured using ELISA system and aromatase mRNA level in brain was observed using RT-PCR technique. In all female fish, vitellogenin levels were in the range of 20∼40 $\mu\textrm{g}$/ml and aromatase mRNA expression could be detected on the agarose gel after RT-PCR. However, in case of males, vitellogenin level was elevated in only one fish, while vitellogenin was hardly detected in others. Aromatase was expressed in all males although the levels were relatively lower than the level in female fish. Testis-ova and any other histological changes of reproductive organ were not shown in both sexes.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.206-212
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• 2004

In an effort to develop the tools for monitoring the contamination of xenoestrogen in the aquatic environment of Korea, reverse transcription-polymerase chain reaction (RT-PCR) analysis of vitellogenin (VTG) mRNA expression were optimized in Synechogobius hastus. Based on the partial VTG cDNA sequence VTG mRNA level in livers from male fishes was analyzed by RT-PCR. As an internal control beta actin mRNA was amplified. 3 ${\mu}g$ of total RNA was reverse transcribed in 20 $\mu$l reaction using murine leukemia virus 〔MuLV〕 reverse transcriptase. Subsequent PCR using the 1 ${\mu}g$ of cDNA resulted in linear increase in PCR product of VTG in female liver cDNA from 10 to 30 cycles of amplification. On the contrary, in male, PCR product first detected at 28 cycles of amplification and linearly increased during 38 cycles of amplification, suggesting that male S. hastus expresses minute amount of VTG mRNA which is $2^{-18}$ equivalent of female. In conclusion, the optimized protocol of VTG mRNA expression in the liver of male S. hastus will be promising the environmental monitoring the xenoestrogen contamination in the western coast and estuaries in Korea.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.3
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• pp.279-288
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• 2020

Changes of gonadal morphology and mRNA expression patterns of vitellogenin were investigated in Siberian sturgeon Acipenser baerii (Chondrostei) during its early gonadal maturation period. Early differentiations and morphological transitions of both ovaries and testes appeared to occur actively until the age of 3 years, however from then on, the maturation patterns to full maturity were largely gender-dependent, in which males showed a faster progression of maturation than did females while females experienced a steady-state progress with a lagged interval before entering the final maturation. Expression of vitellogenin mRNAs are closely correlated with transitional patterns of gonadal appearances. In both females and males, hepatic mRNA levels of vitellogenin exponentially increased in the earliest interval (up to 1-year-old). However, in subsequent periods, vitellogenin expression in females continued to increase with age, whereas in males, the expression stabilized at a younger age. Nevertheless, at the age older than or equal to 7-year-old, fully matured individuals showed a quite low level of vitellogenin expression in both females and males. Collectively, results from this study could be useful as a fundamental guideline to address the gonad maturation of this sturgeon species, which is helpful for making practical decisions about farming practices and management for caviar production on local sturgeon farms.

• Korean Journal of Environmental Biology
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• v.22 no.2
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• pp.329-335
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• 2004

To develop a biomarker for the monitoring of the contamination of estrogenic endocrine disrupters in the aquatic environment, reverse transcription -polymerase chain reaction (RT-PCR) analysis of vitellogenin (Vg) mRNA expression was optimized in Bombina orientalis, a Korean red bellied toad species. Based on partial cDNA sequences of both Vg and beta actin genes of B. orientalis, specific primers for RT-PCR of Vg and beta actin mRNAs were developed. Semiquantitative RT-PCR of the Vg mRNA in liver was optimized using a beta actin mRNA as an internal control in both sexes. In female RT-PCR using $1\;\mu{g}$ of the liver cDNA resulted in a linear increment in the PCR product of Vg from 18 to 34 cycles of amplification. In male, on the contrary, the RT- PCR product was first detected at 30 cycles of amplification and a linear increment was observed from 30 to 40 cycles of amplification, suggesting that male B. orientalis expresses minute amount of Vg mRNA which is a $2^{-12}$ equivalent of female. In conclusion, the optimized protocol for semiquantitative RT-PCR analysis of Vg mRNA level in B. orientalis male liver will be useful for the environmental monitoring the xenoestrogen contamination in the freshwater environment in Korea.

• Journal of Aquaculture
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• v.13 no.1
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• pp.79-85
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• 2000

The effects of estrogen and androgens on Vg gene expression were examined in primary hepatocyte culture and livers of the immature male trout. Specific primers of Vg cDNA were designed with already reported Vg gene nucleotide sequences. PCR product was sequenced and verified with Vg cDNA of rainbow trout. Total RNA was extracted from the cultured hepatocytes and livers of steroid-treated rainbow trout and then it was analyzed by reverse transcriptase- polymerase chain reaction (RT-PCR) analysis. The Vg mRNA and Vg protein synthesis were increased in rainbow trout in vivo and in vitro with E$_2$ and methyltestosterone (MT) There were dose and time-related effects of E$_2$ and MT on vitellogesis. Androgens such as progesterone androsterone and testosterone also stimulated Vg mRNA expression in vitro. The results show that androgens as well as E$_2$ can induce expression of Vg mRNA in trout in vivo and in vitro.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.122-129
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• 2004

In an effort to develop the biomarker for monitoring the contamination of xenoestrogen in the freshwater environment of Korea, reverse transcription-polymerasechain reaction (RT-PCR) analysis of vitellogenin (VTG) gene expression was optimized in Hearisarsus Iaseo, Based on the homology of the VTG cDNA sequences between the common carp and zebra fish, a set of PCR primers for VTG mRNA amplification for H; labo was designed. VTG mRNA level in livers from female and male fishes was analyzed by RT-PCR following single injection of 17 beta estradiol($E_2$ 10 mg $kg^{-1}$ B.W.). As an internal control, beta actin mRNA was amplified. One us of total liver RNA was subjected to RT-PCR. In female the amount of PCR productof VfC gradually increased in the range from 16 to 34 cycles of amplification. On the contrary, in control male, PCR product first detected at 32 cycles of amplification and linearly increased up to 40 cycles of amplification. In $E_2$ injected male liver, the VTC mRNA level was similar to that in the female. Taken together, this result suggests that liver of male H. labo expresses minute amount of VTG mRNA which are2-l6 equivalent of female and that induction of VTG mRNA occurs in male liver after estrogen treatment. In conclusion, the optimized protocol for RT-PCR analysis of VTG mRNA expression in liver of male H. labo will provide the environmental monitoring method for the xenoestrogen contamination in the rivers in Korea.

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