• 한국가금학회지
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• 제28권1호
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• pp.69-76
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• 2001

Avian primordial germ cells (PGCs) originate from the epiblast and appear in the germinal crescent. These PGCs enter the developing blood vessels during stage 10∼12 (H&H), circulate in the blood stream, migrate into the developing gonadal anlage and differentiate into germ cells. However, it is not clear until when the migratory ability of PGC is maintained. This study was conducted to examine whether migratory ability is present in PGCs from the gonad at later embryonic developmental stages. In the present study, gonads were dissected from 5-, 6- and 10-day old quail embryos and treated with trypsin-EDTA. Gonadal PGCs (gPGCs) were purified by Ficoll-density-gradient-centrifugation and labeled with PKH26 fluorescent dye. The PKH26-labeled gPGCs were microinjected into the blood vessel of the recipient quail embryo. Manipulated recipients were incubated for 3 days, embedded in paraffin and sdctioned. The foreign gPGCs were detected by fluorescent and confocal laser microscopy. As a result, quail gPGCs, from 10, 6 and 5 day old embryos could migrate through the recipient blood stream at early stage and settle in the gonads. Thus, results suggest that gPGCs from upto 10-day old embryos keep properties seen in circulating PGC. Therefore, the PGCs of 10-day old embryonic gonads can be used for the tools of genetic manipulation.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2000년도 제17차 정기총회 및 학술발표
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• pp.75-77
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• 2000

Retaining migratory activity is a prerequisite for the manipulation and use of PGCs. This study was conducted to examine whether migratory activity is retained in the primordial germ cells(PGCs) from gonads at the later embryonic developmental stage. In the present study, gonads were dissected from 5-, 6- and 10-day-old quail embryos and treated with trypsin-EDTA for the degradation of gonadal tissue. Gonadal PGCs (gPGCs) were purified by Ficoll density gradient centrifugation and labeled with PKH26 fluorescent dye. The PKH26-labeled gPGCs were microinjected into the blood vessels of recipient quail embryo. After further incubation of 3 days, the manipulated recipients were embedded in paraffin and sectioned. The gPGCs were detected by their fluorescence under the fluorescent microscopy and the confocal laser microscopy. As a result, 10-day-old quail gPGCs as well as 5-and 6-day-old gPGCs, could migrate to recipient embryonic gonads and settle down. These results suggest that the 10-day-old gPGCs have the properties of circulating PGCs at early stage. Therefore the PGCs from 10-day old embryonic gonads can be used for the tools of genetic manipulation.

• 한국수산과학회지
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• 제44권6호
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• pp.569-576
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• 2011

Proximate and fatty acid compositions in muscle tissue were studied in 14 species of coastal and offshore fishes in Korea. Lipid content ranged from 0.57 to 10.5% and was higher in migratory and reef dwelling fishes than in demersal fishes. Protein content ranged from 14.4 to 20.3% and moisture content ranged from 72.4 to 81.8% in all fish samples. There was a negative correlation between lipid and moisture content in all fish samples (r= -0.90, P<0.001). The prominent fatty acids were 16:0, 22:6n-3 (docosahexaenoic acid, DHA), 18:1n-9, 20:5n-3 (eicosapentaenoic acid, EPA), 16:1n-7, 18:0 and 18:1n-7. Most demersal fishes contained considerably higher amounts of 20:4n-6 and/or 22:5n-3 compared with migratory and reef dwelling fishes. The proportion of total polyunsaturated fatty acid (PUFA), including DHA and EPA, was higher in demersal fishes (38.6-54.0%) than in migratory and reef dwelling fishes (23.5-35.2%).

• Entomological Research
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• 제48권6호
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• pp.522-532
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• 2018

As the vector-borne diseases rapidly increased due to climate change, we investigated the incidence of flavivirus occurrence among female mosquito species in urban and rural study sites in Daegu and Gunwi, South Korea using Realtime PCR. We collected more individuals and more species of mosquito in 2016 than in 2015. In 2015, we recorded a total of 22,033 mosquitoes (Trap Index, 224.8) representing 10 species from 5 genera, whereas in 2016, a total of 27,137 mosquitoes (Trap Index, 278.7) representing 13 species from 6 genera were collected. The number of mosquitoes in 2016 was higher in all study sites, except in the migratory bird habitats where the number decreased. Of the 14 species collected over the two years, Aedes vexans nipponii and Anopheles spp. were dominant in the cowsheds in rural farmland; Culex pipiens complex, in urban residential areas; and, Anopheles spp. and Cu. pipiens complex in migratory bird habitats caught in a black light trap. Cu. pipiens complex and Ae. albopictus in urban parks and Ae. albopictus and Armigeres subalbatus in migratory bird habitats were the dominant species caught in BG-sentinel traps. We found that the number of mosquitoes was highest during July-September. We analyzed 1,725 pools to detect flavivirus, where Chaoyang virus was detected among Ae. vexans niponii collected from cowsheds in rural farmland in 2016. The increased number of mosquitoes recorded in 2016 was mainly due to increased temperatures in the study areas, and reflected the change in study sites.

• 생태와환경
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• 제53권4호
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• pp.453-460
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• 2020

Bolboschoenus planiculmis is an important prey species for winter migratory birds in the Nakdong River Estuary region, but its population has declined in the last decade due to a physio-chemical shift. To identify the growth and development characteristics of B. planiculmis, we carried out an experimental survey on the aboveground and belowground sections of B. planiculmis specimens in the Eulsuk tidal flat from April to September 2019. We divided the belowground area into two groups: a vegetation group in which B. planiculmis exists and a non-vegetation group in which B. planiculmis does not exist and measured the rate of tubers. We observed a 45% appearance frequency in the vegetation group and only a 5% frequency in the non-vegetation group, indicating that there were no supplies for plant growth. The mean density, length, and biomass of B. planiculmis aboveground were 166.90±149.62 n m^-2, 44.39±5.45 cm, and 67.63±54.46 g DW m^-2, respectively, which was approximately half of those obtained from the study in the Eulsuk tidal flat in 2002. Tuber number was the highest in the 15~25 cm deep layer(41.50%). The mean number of total tubers belowground was related to different sediment conditions(FS: flat surface, DS: disturbed surface) 251.75±16.86 n pot^-1 for FS and 171.00±25.18 n pot^-1 for DS, which was significantly different(total tubers: p<0.005). The mean biomass of B. planiculmis above-ground was 21.11±1.60 g DW pot^-1 for FS and 15.41±1.38 g DW pot^-1 for DS, which was significantly different(p<0.05). This research provides primary materials for the restoration of the Nakdong River Estuary, wintering sites for migratory birds, and protection of B. planiculmis.

• 한국환경과학회지
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• 제30권12호
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• pp.1067-1079
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• 2021

The coastal water is a space where salmon (Oncorhynchus keta), critical energy-conveying mediator, stay to adapt to different environments while traveling between ocean and river ecosystems for spawning and growth. The mid-eastern coast of Korea (MECW) is the southern limit of salmon distributed in the North Pacific Ocean. Understanding the distribution and migration characteristics of salmon in the MECW is important for the prediction of changes in the amount and distribution of salmon related to changes in the future marine environment. We analyzed the relationship between the salmon migratory timing ascending the Wangpi river and change in vertical seawater temperature and tidal elevation. Overall results highlight that (1) Salmon began to ascend the river when the sea surface water temperature (SST) decreased below 20℃; (2) The number of salmon ascending the river increased when the temperature difference between the upper and lower layers decreased, but decreased when the temperature difference was higher than 5℃; (3) The number of salmon ascending the river peaked, when the SST was 18℃-19℃ and sea levels rose at high tide. This study provide important insight into predicting changes in the ecosystem energy circulation through climate change at its southern distribution limit.

• Molecules and Cells
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• 제45권12호
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• pp.935-949
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• 2022

Liver cancer has a high prevalence, with majority of the cases presenting as hepatocellular carcinoma (HCC). The prognosis of metastatic HCC has hardly improved over the past decade, highlighting the necessity for liver cancer research. Studies have reported the ability of the KiSS1 gene to inhibit the growth or metastasis of liver cancer, but contradictory research results are also emerging. We, therefore, sought to investigate the effects of KiSS1 on growth and migration in human HCC cells. HepG2 human HCC cells were infected with lentivirus particles containing KiSS1. The overexpression of KiSS1 resulted in an increased proliferation rate of HCC cells. Quantitative polymerase chain reaction and immunoblotting revealed increased Akt activity, and downregulation of the G1/S phase cell cycle inhibitors. A significant increase in tumor spheroid formation with upregulation of β-catenin and CD133 was also observed. KiSS1 overexpression promoted the migratory, invasive ability, and metastatic capacity of the hepatocarcinoma cell line, and these effects were associated with changes in the expressions of epithelial mesenchymal transition (EMT)- related genes such as E-cadherin, N-cadherin, and slug. KiSS1 overexpression also resulted in dramatically increased tumor growth in the xenograft mouse model, and upregulation of proliferating cell nuclear antigen (PCNA) and Ki-67 in the HCC tumors. Furthermore, KiSS1 increased the angiogenic capacity by upregulation of the vascular endothelial growth factor A (VEGF-A) and CD31. Based on these observations, we infer that KiSS1 not only induces HCC proliferation, but also increases the metastatic potential by increasing the migratory ability and angiogenic capacity.

• Ecology and Resilient Infrastructure
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• 제10권4호
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• pp.258-265
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• 2023

대부분의 어류가 생존을 위해 회유 또는 이동하는 특성이 있음에도 불구하고 국내에 설치된 어도는 평상시에 고유속과 저수심의 흐름이 발생할 수 있어 어류의 이동에 장애가 되고 있는 실정이다. 또한 어도에 관한 국내 설계기준상 국내 하천에 서식하는 다양한 어종별 유영특성을 고려하지 못하는 한계가 있다. 따라서 어도의 기능을 확보하기 위한 설계기준의 마련이 필요하며, 이를 위해 국내 회유성 어종의 유영특성과 어도의 수리특성에 대한 연구가 필요하다. 이에 본 연구에서는 붕어를 대상으로 증진유속방법과 고정유속방법을 수행하여 가능한 객관적인 어류의 유영특성을 분석하고 한계유영유속을 제시하였다. 증진유속방법 실험을 수행한 결과 붕어는 0.7 m/s ~ 0.8 m/s로 하는 것이 바람직한 것으로 확인되었다. 고정유속방법 실험을 수행한 결과 붕어의 경우는 0.8 m/s 정도로 확인되었다. 따라서 두 실험 방법을 종합적으로 분석한 결과 어도설계를 위한 한계유영유속을 결정하면 붕어의 경우는 약 0.8 m/s로 판단된다. 향후 다양한 회유성 어종에 대해 유영특성의 실험적 연구를 수행하여 어도설계를 위한 대상어종별 유영특성을 고려한 어도설계기준 마련이 필요하다.

• 환경생물
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• 제39권2호
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• pp.195-206
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• 2021

우리나라에서는 2020년에 생태계 건강성 측면에서 어류의 상하류 간 종적연결성 평가법에 대한 연구개발에 착수하였다. 본 연구는 최근 어류이동을 위한 아이스하버식 어도의 횡단구조물 개선이 이루어진 연곡천 송림보에서 2015~2020년 장기간 동안 보의 상하류 회유성 어종 이동성, 어류분포 특성, 섭식길드, 내성도 길드 및 종조성 변화를 분석하였다. 어류는 총 36종 5,136개체가 채집되었으며, 주요 회유성 어류는 황어(Tribolodon hakonensis), 은어(Plecoglossus altivelis altivelis), 연어(Oncorhynchus keta)로 3종이 확인되었다. 어도의 개선 이전(Pre-I)과 이후(Post-I) 비교분석에 따르면, 상류구간에서 일차담수어의 상대풍부도는 증가한 반면, 회유성 어종은 감소하였다. 송림보의 상/하류구간에서 어도(Fishway)를 이용하는 어류는 황어(58.4%), 은어(11.8%)로 나타났고, 상/하류 구간의 Wilcoxon Signed-Rank Test에 따르면, 회유성 어류는 통계학적으로 유의한 차이를 보여(p<0.05), 횡단구조물에 대한 생물학적 개선효과를 보였다. 한편, Mann-Kendall trend test 기반의 회유성 어류의 연별 변화는 유의한 수준(p>0.05)의 증가 혹은 감소의 경향은 확인되지 않았다. 따라서 어도의 개선 사업 시에는 물리적, 수리수문학적, 구조적 테스트뿐만 아니라 사전 및 사후의 어도이용 및 개선 효과에 대한 생물학적 시험도 반드시 필요할 것으로 사료된다.

• 한국지구과학회지
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• 제33권4호
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• pp.337-349
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• 2012

본 연구에서는 1000 hPa면 고도 자료 및 K-평균 군집분석법을 활용하여 한반도 주변 기압배치를 분류하고, 각 유형의 특성을 조사하였다. 군집의 기준으로 기압배치 공간 형태의 유사성을 나타내는 패턴 상관계수를 사용하고, 유사성의 경계치로 0.8을 적용하여 대표적 기압배치 유형 11개를 얻었다. 이들은 시베리아 기단이 한반도 주변으로 장출하는 경로에 따라 3개, 북태평양 고기압의 중심 위치에 따라 3개, 시베리아 및 북태평양 기단의 영향권에서 기압골이 나타나는 유형 2개, 그리고 봄가을에 주로 나타나는 이동성 고기압형으로 고기압의 장축방향에 따라 3개 등이다. 각 기압 배치 유형의 출현빈도로부터 추정한 한반도에 영향을 주는 기단의 출현비율은 시베리아 기단 55.4%, 북태평양 기단 29.3%, 양쯔강 기단 12.8%, 오호츠크해 기단 2.5% 순이며, 한반도는 대륙에서 기원한 기단의 영향이 68.2%로 지배적이다. 한반도 주변 기압계는 겨울 기압배치 유형과 여름 기압배치 유형이 각기 대륙과 해양에 발달하는 정체성 기단으로부터 확장되는 고기압을 중심으로 하여 대조적으로 출현하고, 봄가을의 이동성 고기압형은 이들의 변환 과정에서 나타난다. 근래 여름 북태평양 고기압의 한반도 출현빈도가 감소하고 있다. 그리고 겨울 기압배치 유형의 출현이 봄가을에 자주 나타나면서 기압골을 갖는 기압배치 유형의 출현빈도가 증가하고, 이동성 고기압형은 거의 모든 계절에 나타나는 경향이 있다.