• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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• pp.121-121
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• 2001

Studies were carried out to compare the bioconcentrations of TCDD and PCB 126 in different sizes of Japanese medaka, and to examine the whole body elimination kinetics of TCDD and PCB 126 in juvenile Japanese medaka. For bioconcentration studies, different sizes of fry and juvenile medaka were exposed statically to varying doses of waterborne TCDD and PCB 126 for 96 hours. (omitted)

• Environmental Analysis Health and Toxicology
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• 제15권3호
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• pp.61-67
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• 2000

Toxic lesions of styrene in the Japanese Medaka (Oryzias latipes) were compared with those of styrene oxide, the active metabolite of styrene, using embryo-larval assays. The developmental stages of Japanese Medaka (Oryzias latipes) treated with both chemicals were not altered and progressed normally. However, styrene oxide was more toxic than styrene in terms of causing death and lesions . High concentrations of styrene (higher than 4.9 ppm) and styrene oxide (higher than 2.4 ppm), resulting in more than 50% mortality, caused similar lesions of cardiovascular system, craniofacial bone formation and spinal deformities, although a number of lesions were not observed by both chemicals . In the group treated with styrene, eyeball sizes and intereye distances were reduced, while, in the group treated with styrene oxide , the eyes and eye cups were not developed and two eyes were sometimes fused. In addition, styrene oxide caused the lesion which involved the posterior brain and brain stem were herniated through the spinal cord . The noticeable difference of toxic symptoms between these two chemicals was the time of onset. Toxicities of cardiovascular system and craniofacial bone formation appeared on day 3 of development in styrene oxide treated group, but, styrene treated group staned to show hemorrhages on day 3 and the craniofacial malformation were appeared on day 5, These differences between two chemicals may be due to the metabolism of styrene to styrene oxide, the reactive intermediate.

• Environmental Analysis Health and Toxicology
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• 제14권1_2호
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• pp.55-63
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• 1999

Endocrine disrupting chemicals probably cause the cytological or/and morphological changes of germinal cells in gonad. Accordingly, this study was aimed to make sure that the effect of hormone-mimicking chemicals on gonad morphology such as decrease of germinal cells, inhibition of cellular maturation and change in the ratio of germinal cells in the different developmental phase can be observed by histopathological procedures and can be a useful bio-indicator for the evaluation of endocrine disruption by environmental chemicals. In this experiment, female Japanese medaka were exposured to quercetin, a phytoestrogen, at the concentration of 100 $\mu\textrm{g}$/L. quercetin showed the significant decrease in the number and rate of vitellogenic follicular oocytes in the treated group for 4 and 6 weeks. The weak development of yolk could be also observed. We could conclude that quercetin has anti-estrogenic or androgen-like potency by exerting the inhibition effect on oogenesis in fish female- gonad. From the result of this study, the applied methods and techniques can be evaluated to be a useful biomonitoring means for water pollution, expecting a good result of the subsequent study on apoptosis.

• 한국환경보건학회지
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• 제33권6호
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• pp.513-516
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• 2007

This investigation was intended to find out the estrogenic effect of chlortetracycline (CTC) on vitellogenin induction in adult male Japanese medaka (Oryzias latipes). Vitellogenin (Vtg) produced in male fish has been used to as one of a biomarker of endocrine disrupters. The positive control was $17{\beta}-estradiol$ (E2) that induced Vtg in male fish. As a result, male and female fish were exposed to 0.1, 1, 10 and 100 ppm of CTC. Western blot results showed approximately 205 kDa, that is similar to myosin at high molecular weight range Sigma maker. Vtg band was showed fainted to 10 and 100ppm for chlortetracycline. Vtg concentration of CTC was qunatified by total protein quantification and ELISA. Exposure of the male fish to CTC of 0.1, 1, 10 and 100 ppm produced Vtg concentrations of 0.24, 0.12, 7.61 and 40.02%o, respectively, that value was elevated than control male fish (0.14%o). CTC exerted as a Vtg inducer in male fish from 10 ppm, but it was a reducer in female fish from 0.1 ppm level. The results say that vitellogenin induction patterns alter in male medaka treated with CTC, and that CTC may caused endocrine disruption in fish.

• 한국환경보건학회지
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• 제33권3호
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• pp.207-210
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• 2007

The study was designed to determine the estrogenic effect of some penicillins on endocrine function in adult Japanese medaka (Oryzias latipes). Vitellogenin (Vtg) produced in male fish has been used for a biomarker to study endocrine disrupters. $17\beta-estradiol\;(E_2)$ was used a positive control that was induced Vtg in male fish. Result of total protein qantification and ELISA for female and male fish were exposed to $17\beta-estradiol$ 10ng/ml for $3\sim5$ days. As a result, male fish exposed to amoxicillin respectively appeared 0.75, 0.23, 8.21 and $9.36\%_{\circ}$ of 1, 10, 100 and 1000 ppm respectively, that value was elevated compared with control male fish. Male fish exposed to ampicillin respectively appeared 1.85, 4.68, 0.85 and $39.59\%_{\circ}$ of 1, 10, 100 and 1000 ppm respectively, that value was elevated compared with control male fish. This study is one of the first reports suggesting potential endocrine disruption of some penicillins in aquatic ecosystem. These results suggest that vitellogenin and estrogen receptor induction patterns alter in male medaka treated with selected estrogenic compounds, and that these results may be useful molecular biomarkers for screening estrogenic EDCs (endocrine-disrupting chemicals) in the shortest possible time.

• 한국환경보건학회지
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• 제29권2호
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• pp.7-15
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• 2003

DEHP는 대표적인 플라스틱 가소제 가운데 하나로서, 광범위하게 사용되고 있으며, 내분비계 장애물질로 분류퇴고 있다. 실제로 하천, 해양, 토양 등 광범위한 환경에서 검출되고 있지만, 이 물질이 수서 생물에 미치는 내분비교란 영향과 기작에 대해서는 거의 알려진 바가 없다. 본 연구에서는 송사리로 불리우는 Oryzias latipes(Japanese medaka)와, 유생 시기에 저니성 무척추 동물로 존재하다가 성충이 되는 Chironomus riparius를 대상으로 DEHP가 내분비 장애물질로서 생식작용에 미치는 영향에 대하여 연구하였다. 먼저, Japanese medaka를 부화 직후부터 3개월간 DEHP 1, 10, 50 $\mu\textrm{g}$/l의 농도로 노출시킨 결과 암놈의 혈중 비텔로제닌의 감소 ,생식소 지수인 GSI(Gonado Somatic Index) 감소. 난자 발달 저해 등이 관찰되었다. 또한, C. riparius를 산란 직후부터 DEHP에 노출시킨 경우에는 성체 출현률, 암수 비율, 산란률에서는 용량-반응 관계를 가진 변화가 발견되지 않았으나, 산란된 알의 부화율은 DEHP에 노출된 경우 유의하게 감소하는 것이 관찰되었다. 이러한 결과를 종합하여 볼 때. DEHP는 O. latpes와 C. riparius 모두 생식 작용에 영향을 미치며, 그 작용 기작은 일반적으로 발견되는 에스트로젠(estrogen) 활성이 아닌 암놈의 생식기관의 발달을 직, 간접적으로 저해함으로서 정상적인 알의 생성을 방해하는 이른바 항-에스트로젠 기작을 보이는 것으로 추정된다. 본 연구에서는 DEHP 위해성 평가를 위한 기본 자료로서, 생식작용 영향에 대한 새로운 자료를 제시하였다.

• Environmental Analysis Health and Toxicology
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• 제18권2호
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• pp.155-163
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• 2003

Fluoranthene, a common polycyclicaromatic hydrocarbon (PAH), exhibits phototoxicity which may affect aquatic organisms. The eventual goal of this study is to develop a biomarker of Japanese medaka (Oryzias latipes) used in monitoring hazardous chemicals in the ecosystem. In this study we investigated neural toxicity of fluoranthene in Japanese medaka (Oryzias latipes) along with comparative analysis of corresponding behavioral response. The untreated individuals shooed normal behavioral characteristics (i. e., smooth and linear movements). The treated fish, however, showed stopping and abrupt change of orientation (100 ppb), and severely reduced locomotive activity and enhanced surfacing activity (1,000 ppb). Treatment of the medaka fish with fluoranthene caused a significant suppresson of acetycholine esterase (AChE) activities in the body portion but not in the head portion. When fish were exposed to 1,000 ppb of fluoranthene for 24 hr, the body AChE activities decreased from 126.${\pm}$31.89 (nmoles substrate hydrolyzed per min per mg protein) to 49.51${\pm}$11.99. Expressions of tyrosine hydroxylase (TH) protein in the different organs from both head and body portions were comparatively analyzed using an immunohistochemical technique. Five organs of the medaka fish showing a strong TH protein expression were the olfactory bulb, hypothalamus, optic lobe, pons and myelencephalon regions. This study provides molecular and neurobehavioral bases of a biomonitoring system for toxic chemicals using fish as a model organism.

• 환경생물
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• 제26권3호
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• pp.220-225
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• 2008

In this study, alterations in whole proteome expression patterns in the head of Japanese medaka (Oryzias latipes) was investigated following acute or chronic exposure to benzo(a)pyrene (BaP) (25 ${\mu}g$ L$^{-1}$) for 48 hrs and 15 days, respectively. The results showed that 9 and 6 protein spots were statistically different, relative to controls, in response to acute and chronic BaP exposure, respectively. In the acute exposure group, 5 spots were up regulated and 4 spots were downregulated, while in the chronic exposure group, 4 spots were upregulated and 2 spots were downregulated. Three of these spots were common to both the acute and chronic BaP exposure groups and were identified using LC-MS/MS followed by database searching. These 3 spots were found to be associated with structural proteins belonging to the actin and keratin families. These data suggest that acute and chronic exposures to BaP may affect tissue morphology in the head of Japanese medaka.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.23-24
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• 2003

The goal of this study is to develop a biomarker used in monitoring abnormal behaviors of Japanese medaka (Oryzias latipes) as a model organism caused by hazardous chemicals. Japanese medaka was treated by copper and fluoranthene of appropriate sublethal concentrations after starvation for 48 hr. In this study we investigated neural toxicity of copper and fluoranthene in Japanese medaka (Oryzias latipes) along with comparative analysis of corresponding behavioral responses. The untreated individuals showed common behavioral characteristics (i.e., smooth and linear movements). Locomotive activity of the fish was monitored using an image processing and automatic data acquisition system. When treated with copper (100 ppb), the fish showed shaking patterns more frequently. As the concentration of copper increased to 1,000 ppb, activity decreased, and the fish showed an erratic movement. The treated with fluoranthene, however, showed stopping and abrupt change of orientation (100 ppb), and severely reduced locomotive activity and enhanced surfacing activity (1,000 ppb).

• 한국동물생명공학회지
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• 제35권1호
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• pp.65-72
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• 2020

Fish ovarian germline stem cells (OGSCs) that have the abilities to self-renew and differentiate into functional gametes can be used in various researches and applications. A main issue to be solved for effective utilization of fish OGSCs is the development of their stable in vitro culture condition, but only few researches about fish OGSC culture have been reported so far. In this study, in order to find the clues to develop the culture condition for OGSCs from Japanese medaka (Oryzias latipes), we tried to establish somatic cell lines as a candidate for the feeder cells and evaluated its supporting effects on the culture of ovarian cell populations from O. latipes. As the results, the somatic cell lines could be established only from the embryonic tissues among three tissues derived from embryos, fins and ovaries. Three embryonic cell lines were tested as a feeder cell for the culture of ovarian cell population and all three cell lines induced cell aggregation formation of the cultured ovarian cells whereas the feeder-free condition did not. Furthermore, a significant cellular proliferation was observed in the ovarian cells cultured on two of three cell lines. As a trial to increase the capacity of the cell lines as a feeder cell that supports the proliferation of the cultured ovarian cells, we subsequently established a stable line that expresses the foreign O. latipes fibroblast growth factor 2 (FGF2) from an embryonic cell line and evaluated its effectiveness as a feeder cell. The ovarian cells cultured on FGF2 expressing feeder cells still formed cell aggregates but did not show a significant increase in cellular proliferation compared to those cultured on non-transformed feeder cells. The results from this study will provide the fundamental information for in vitro culture of medaka OGSCs.