• 한국수산과학회지
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• 제43권5호
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• pp.462-473
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• 2010

Inductions of hybrids and reciprocal hybrids between Oryzias dancena and O. javanicus (ODJ and OJD) were conducted and backcross hybrids between female O. dancena and male ODJ were also produced for biological and cytogenetic analysis. Embryonic development of ODJ and OJD were compared with those of their parents. Developmental time was fastest in O. dancena and ODJ, followed by O. javanicus and OJD. Oryzias dancena hatched 11 days (d) after fertilization, ODJ at 13 d, O. javanicus at 14 d and OJD at 15 d. The abnormality of external morphology rate in ODJ was 10.6%; however, OJD showed a high degree of abnormality, over 90%. The proportion of males was 90.0% and 31.3% for ODJ and OJD, respectively. Cytogenetic analysis was conducted to obtain basic information for genetic identification of O. dancena, O. javanicus and their hybrids. The karyotypes of all experimental groups showed 2n=48 chromosomes and the fundamental number (FN) was 48. The first pair carried secondary constrictions near the centromeric regions. Erythrocyte area and volume were $9.8\;{\pm}\;0.5\;{\mu}m^2$ and $18.2\;{\pm}\;1.0\;{\mu}m^3$, respectively, for O. dancena, $8.3\;{\pm}\;0.5\;{\mu}m^2$ and $15.8\;{\pm}\;1.5\;{\mu}m^3$ in O. javanicus, and $18.3\;{\pm}\;0.5\;{\mu}m^2$ and $15.7\;{\pm}\;1.3\;{\mu}m^3$ in ODJ. Erythrocyte area and volume in ODJ were similar to those of O. javanicus. In backcross hybrids between female O. dancena and male ODJ, all embryos failed to develop and died in the late gastrula stage.

• Animal Systematics, Evolution and Diversity
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• 제8권2호
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• pp.177-182
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• 1992

1986년 4월부터 1991년 2월까지 한국의 서남해로 유입하는 하천과 인접 도서지방에 서식하는 송사리 Oryzias latipes의 표본을 조사한 바, 조사수역의 모든 표본은 척추골 수가 28-31개이고, 가슴지느러미 기조수는 9개이며, 2n 염색체 수가 46개 이었다. 이러한 특징은 동해로 유입하는 하천과 남해의 인접 도서지방에 분포하는 O. latipes latipes와는 구별되고, 중국산 O.latipes sinensis와 일치되어 한국 미기록 아종으로 보고하고 이 아종의 국명은 대륙송사리로 명명한다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.155.1-155
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• 1997

• 한국어류학회지
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• 제24권4호
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• pp.247-252
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• 2012

한국산 송사리속 2종에 대한 섭이기관의 구조적 차이를 알아보기 위하여 악골 및 이빨 구조를 조사하였다. 악골에서 송사리 Oryzias latipes는 전상악골 중앙부의 등 쪽 가장자리에 움푹 들어가는 홈이 존재하였으나 대륙송사리 O. sinensis는 일직선이었다. 후반부의 위치에서 송사리는 중앙부와 일직선상에 존재하였으나 대륙송사리는 배 쪽에 존재하였다. 또한 송사리는 하악골의 구상돌기 아래로 이어지는 치골 뒷가장자리에 움푹 들어가는 홈이 존재한 반면에 대륙 송사리에서는 뒷가장자리가 일직선 모양을 하였다. 송사리는 성적이형으로서 수컷에서만 나타나는 큰 이빨이 하악골의 측면 방향으로 발달하였고, 대륙송사리는 등 쪽 방향으로 발달하였다. 한편 송사리의 이빨형태는 원뿔모양과 화살촉모양 2 types이 나타난 반면에 대륙송사리에서는 원뿔 모양 1 type만 나타나는 특징을 보였다. 이상과 같이 한국에 분포하는 2종의 송사리는 섭이기관에서 뚜렷한 종간의 특징을 잘 보여 주었다.

• Environmental Analysis Health and Toxicology
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• 제20권2호
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• pp.187-194
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• 2005

Octachlorostyrene (OCS) is a primarily concerning chemical in many countries because of its persistent and bioaccumulative properties in the environment. OCS is not commercially manufactured or used but it may be produced during incineration or chemical synthetic processes involving chlorinated compounds. There are several reports that OCS was found in the waters, sediments, fish, mussels, and also in human tissues. However, systematic studies on the OCS toxicities are scarce in literature. In this study, we tried to get the gene expression data using medaka DNA chip to identify biomarkers of OCS exposure. Medaka (Oryzias latipes.) was exposed to OCS 1 ppm for 2 days and 10 days, respectively. Total RNA was extracted and purified by guanidine thiocyanate method and the Cy3- and Cy5-labelled cDNAs produced by reverse trancription of the RNA were hybridized to medaka microarray. As results, eighty five genes were found to be down-or up regulated by OCS. Some of the genes were listed and confirmed by real-time PCR.

• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.217-222
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• 1999

Changes in certain fish behaviors are known to be very sensitive indicators of sublethal exposure to environmental contaminants. Therefore, behavioral toxicity tests, if properly designed, can be very useful to assess the influence of hazardous chemicals on fish. However, quantitative analysis of xenobiotic-mediated changes in locomotor behavior in fishes are rare, due mainly to the methodological difficulties. In general, fish movement has been known to be hypertrophic or hypotrophic according to the chemicals. As a study of fish behavioral toxicities, we qualified the swimming movement of Oryzias latipes using computer-automated video tracking system. Oryzias latipes was exposed to cadmium of 128 mg/L for 1 hour in a limited aquaria, then the total swimming distance, the average swimming velocity, the histogram of turning angles, and the turning frequency were analyzed. Fish treated with cadmium showed decreased swimming activities, decreased velocity, and decreased turning frequency, which means hypotrophic activity. From these results, the computer-automated video tracking system of this study seems to be a good tool for the evaluation of the potential ecotoxicological studies.

• Molecular & Cellular Toxicology
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• 제3권3호
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• pp.185-189
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• 2007

Gene expression levels of choriogenin, vitellogenin and estrogen receptor were determined using Reverse transcription (RT)-PCR technique after exposure to estrogenic chemical bisphenol A in the Korean wild medaka (Oryzias sinensis). These genes have been known to be induced in male test fish when the fish are exposed to estrogenic chemicals. Therefore they can be suggested as a possible biomarker of endocrine disruption in fish, however, relatively little has been known about these genes expression by estrogenic chemicals in Korean wild fish. Mature male Oryzias sinensis were treated with bisphenol A at nominal concentrations of 0.02, 0.2 and 2 mg/L for 6 days and total RNA was extracted from the livers of treated fish for RT-PCR. When the five biomarker genes were amplified by RT-PCR in the same condition, mRNA induction level of each gene was elevated with different sensitivities. Conclusively, the results of this work indicated that measurement of vitellogenin and choriogenin using RT-PCR is effective as a simple tool for the screening of estrogenic chemicals and suggested that O. sinensis would be a suitable model fish for the environmental risk assessment of potential endocrine disruptors.

• 한국어류학회지
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• 제21권3호
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• pp.141-148
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• 2009

Oryzias dancena를 해양생태계 위해성 평가를 위한 해양 생물모델로 연구하기 위한 기초적인 연구로 초기 성분화와 생식소 발달 과정을 조직학적으로 조사하였다. 원시생식세포가 처음 관찰된 시기는 수정 후 5일째이고, 수정 후 9일째에 장과 앞신장관 사이의 생식소 형성 부근으로 이동한 것이 관찰되었다. 부화 후 12일째의 생식소는 암 수로 분화가 이루어졌다. 부화 후 28일째 난소에서는 주변인기의 난모세포가 관찰되었으며, 28일째의 정소에서는 정소 소관의 수와 정원세포의 증가를 확인할 수 있었다. 산란은 부화 후 9주째에 이루어졌으며, 이 시기의 난소에서는 난황과립이 난 전체에 형성되는 성숙난과 배란 직후 성숙난이 빠져나간 흔적이 관찰되었다. 수컷 생식소에서 역시 많은 수의 정세포가 관찰되었으며 사정 직후 정자가 빠져나간 부분이 관찰되었다. 이상의 결과 본 종은 초기 성분화 과정에 자성 단계를 거치지 않고 정소와 난소로 분화하는 분화형 자웅이체에 속한다.

• 한국어류학회지
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• 제21권4호
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• pp.227-238
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• 2009

Oryzias dancena의 난발생 과정과 자치어의 형태발달에 관하여 관찰하였다. 수온 $25{\pm}1^{\circ}C$에서 수정란은 수정 후 1시간이 경과하면 배반이 형성되었다가 30분의 간격으로 4세포기까지 난할이 이루어졌다. 이후로 발생의 속도가 느려져 수정 후, 7시간 45분이 경과된 후 포배기에 이르렀다. 수정 후 5시간 30분 후에 상실기에 도달하였으며, 포배기는 수정 후 7시간 45분 후에 이루어졌다. 수정 후 11시간 30분이 경과된 후 낭배기에 이르렀고, 수정 후 1일 6시간 후, 신경배를 형성하였다. 심장 박동이 시작되는 시기는 수정 후 2일 4시간째에 이루어졌으며, 수정 후 6일 12시간째 장기에 혈관이 형성되었다. 수정 후 11일째에 부화하였고, 부화 직후 자어는 전장이 $4.40{\pm}0.24mm$였으며, 부화 3일 후에 난황이 완전히 흡수되어 후기 자어기로 이행하였다. 부화 후 21일째에 각 지느러미 기조가 완전하게 형성되어 치어기로 이행하였으며, 이 때 전장은 $8.67{\pm}0.87mm$였다. 최초 산란이 이루어지는 시기는 부화 후 9주째로 전장은 $22.58{\pm}2.73mm$였다.

• 한국발생생물학회지:발생과생식
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• 제18권3호
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• pp.173-178
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• 2014

In order to monitor the developmental features of embryos, larvae, and juveniles of Oryzias latipes (Temminck and Schlegel), Oryzias latipes was caught in river of Shinduck-dong, Yeosu-si, Jeollanam-do, on May 2011, and experiments were carried out in Ichthyology laboratory at Chonnam National University. The blastodisc step was the first level for natural spawning. The optic vesicle, Kupffer's vesicle, myotome began to appear 75 hours 57 minutes later. After blastodisc development, the pectoral fins were made at 143 hours 37 minutes and the tail was separated started at the same time. Hatching was observed at 167 hours 27 minutes after blastodisc. The total length of the hatched larvae was 4.95~5.10 mm (mean, 5.01 mm), the mouth and anus were opened. Larvae used yolk completely after 3 days after hatching. The total length larvae was 5.45~5.56 mm (mean, 5.52 mm) after 8 days after hatching, and appeared the stems for tail. The stems pectoral, anal fin were showed after 14 days and the stems dorsal, ventral fin were appeared after 19 days. For 35 days after hatching, the total length of larvae 13.95~15.30 mm (mean, 14.64 mm), and at this time, fins and body were transferred like the adult Oryzias latipes.