• 환경생물
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• 제38권2호
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• pp.323-331
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• 2020

해산송사리(Oryzias dancena)를 대상으로 한 발생공학 연구시, 현재의 자연산란법은 매우 수동적이고 불편하다. 본 연구에서는 적정 시간에 해산송사리의 수정란을 획득하고자 인공산란을 위한 인간융모성생식선자극 호르몬(human chorionic gonadotropin; HCG)과 잉어 뇌하수체(carp pituitary extract; CPE)의 최적 농도를 조사하였다. 정자활성도, 산란율, 수정 후 3일에서의 수정란 생존율 및 부화율은 100 HCG IU kg^-1 BW (body weight)와 CPE 5 mg L^-1에서 가장 높았다(p<0.05). 본 종에서의 수정란 필요시, HCG와 잉어 뇌하수체 주사를 통하여 적정시간에 미수정란과 정자를 획득할 수 있었다. 본 연구 결과는 해산송사리의 실험동물화 개발에 유용하리라 사료된다.

• 한국발생생물학회지:발생과생식
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• 제17권1호
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• pp.55-62
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• 2013

Puberty is the developmental period which animals obtain the ability of reproducing sexually for the first time in life. In commercially important aquaculture fish species, the onset of puberty is a matter of major interest due to controlling of sexual maturation to improve broodstock management. To investigate pubertal characteristics of female longtooth grouper (Epinephelus bruneus), specimens were classified into three groups by the bodyweight, including 1, 2, and 3 kg group. Thereafter, we focused on ovarian development and level changes of endocrine regulation factors (GnRH, GTHs, steroid hormone). In the non-breeding season (April), the levels of endocrine regulation factors showed increasing trends in accordance with bodyweight gaining; nevertheless, the oocytes were growth phase belongs to almost peri-nucleous stages in all groups. In the breeding season (June), the levels of endocrine regulation factors were fluctuated that decreases in levels of sbGnRH and $FSH{\beta}$ mRNA expressions along with serum $E_2$ concentrations in 3 kg of group. However, $LH{\beta}$ mRNA expression levels sustained increasing trends by the bodyweight. Moreover, the oocytes developed that 2 kg and 3 kg groups obtained plentiful vitellogenic oocytes while 1 kg group was still composed with greater part of pre-vitellogenic oocytes. Especially, the oocytes of 3 kg group reached over 450 ${\mu}m$ of diameters that indicating possibility to enter the final maturations. These results suggest that the progress of pubertal development in female E. bruneus could be classify into three phases via bodyweight, including pre-puberty (1 kg), early-puberty (2 kg) and puberty (3 kg).

• Animal cells and systems
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• 제14권2호
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• pp.125-128
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• 2010

This study investigated the effect of different light intensities on first feeding of chub mackerel Scomber japonicus larvae. Fertilized eggs, obtained from LHRHa-induced spawning of captive broodstock, were stocked (60 larvae/l) into twelve 30-1 aquaria under light intensities of 0, 100, 200, 500 and 1000 lx, with three replicate aquaria per treatment. Temperature was maintained at $20^{\circ}C$ and salinity was 35 psu. Larvae were fed the rotifer Brachionus rotundiformis at a density of five rotifers/ml. Feeding incidence was measured as the percentage of larvae with prey in the digestive tract. Feeding intensity was evaluated as the number of prey in the digestive tract of the larvae. Larvae fed in darkness (0 lx) had significantly lower (P < 0.05) feeding incidence ($13{\pm}0.05%$ larvae with prey) and feeding intensity ($1.00{\pm}0.05$ rotifers per larva) than those larvae fed at 100 ($30{\pm}0.07%$, $1.17{\pm}0.09$ rotifers per larva), 200 ($43{\pm}0.08%$, $1.24{\pm}0.11$ rotifers larvae$^{-1}$), 500 ($53{\pm}0.08%$, $1.48{\pm}0.14$ rotifers per larva) and 1000 lx ($60{\pm}0.08%$, $1.38{\pm}0.13$ rotifers per larva). The feeding incidence of S. japonicus larvae increased with light intensity while feeding intensity showed no significant difference (P > 0.05) between light treatments.

• Fisheries and Aquatic Sciences
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• 제21권11호
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• pp.34.1-34.13
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• 2018

Sexual maturity ($L_{50}$), the length at which 50% of fish in a size class are mature, is a key aspect of domestication of new fish species because it guides the procedure for identification of appropriate broodstock size for artificial spawning. In this study, the $L_{50}$ was determined for 1083 Barbus altianalis samples obtained from Lake Edward and the Upper Victoria Nile. Gonads of freshly killed samples were examined macroscopically and verified with standard histological procedures for the maturation stages that were used to determine $L_{50}$. Oocytes and spermatogenic cell sizes were compared for fish obtained from both water bodies. Results indicated that there were no variations in macro gonad features observed for fish from Lake Edward and Upper Victoria Nile. Similarly, there were no significant differences in oocyte sizes (P > 0.05) between the two populations but significant differences in spermatogenic cell sizes were noted (P < 0.05) except for spermatozoa (P > 0.05). This however did not suggest peculiar differences between the two populations for staging the gonads. Consequently, no staging variations were suggested for both populations in determination of $L_{50}$. Sexual maturity was found in the same class size of fork length (FL) 20-24.9 cm and 35-39.9 cm for males and females from both water bodies, respectively. At this FL, however, males were too small, and for good selection of vigor broodstocks for spawning and conservation purposes, they are better picked from class size of 30-34.9 cm FL and above. These findings were crucial for integration of appropriate breeding size in spawning protocol by farmers and fisheries scientists conserving wild B. altianalis populations.

• 한국수산과학회지
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• 제57권4호
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• pp.448-458
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• 2024

The direction of eye movement in Pleuronectiformes is species-specific. In farmed flounder, deviations in eye direction can reduce marketability. Therefore, we explored the effects of genetic and environmental factors on the direction of eye movements in the starry flounder Platichthys stellatus to address this economic challenge. Four pairs of female and male starry flounder broodstock, with eyes positioned to the right or left, were used in a mating experiment. The experimental groups were established with breeding seawater temperatures set at 10, 14, and 18℃ for the water temperature experiment. Whole-body samples of juveniles were collected to analyze the expression of genes related to eye movement and direction. The mating experiment results showed no significant differences in abnormal eye movement. In the water temperature experiment, the rate of abnormal eye movement was significantly higher at 32.19±1.33% in the 18℃ group than in the 10 and 14℃ groups. Genetic analysis of eye movement related to water temperature revealed that the expression of eye migration genes was significantly higher at 10℃. Moreover, no significant differences were observed in mating experiments. In conclusion, water temperature and not mating affected the eye movement of starry flounder.

• 한국패류학회지
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• 제30권4호
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• pp.303-309
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• 2014

코끼리조개의 대량 인공종묘생산을 추진하기 위한 기초연구로서 수정란, 유생 및 치패의 발달을 조사하였다. 생식체는 잘 성숙한 어미에서 추출하여 희석 정자 용액으로 수정하였으며, 발생유생은 수온 $19{\pm}1^{\circ}C$로 유지하였다. 수정란의 난경은 평균 $81.6{\mu}m$ 이었으며, 수정 후 14시간 만에 담륜자 유생이 되어 부상하고, 27시간 만에 D상 유생 (각장 $116{\mu}m$)으로 발달하고, 20일 후에는 각장 $311.2{\mu}m$로 성장하여 바닥에 안착하였다. $18.5-21.5^{\circ}C$에서 정상적으로 부화 및 유생사육이 가능하였으며, 채묘기질은 모래가 우수하였으나 캐시미론도 양호하였다. 부유유생이 착저한 후 108일간 사육한 결과 각장 13 mm, 전중량 0.4 g으로 성장하였고 일간성장률은 각장 $117.5{\mu}m$ 이었으며, 자연해수로 연중 실내육성이 가능하였다.

• 한국양식학회지
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• 제17권2호
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• pp.115-121
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• 2004

최근, 곰소만에서 채집한 시료로부터 최초의 온대역산 광합성 섬모류 Mesodinium rubrum MR-MAL01 배양체를 분리ㆍ배양하였다. 이 섬모류를 이용하여 이매패류의 섭식실험을 수행한 결과, 비단가리비와 바지락과 같은 이매패류가 섬모류를 직접 섭식 하였음을 확인하였는데, 개체 당 최대 섭식률은 비단가리비 9,590 cells $min^{-1}$, 바지락 23,200 cells $min^{-1}$으로 나타났다. 또한 비단가리비의 소화관에서 완전한 M. rubrum세포를 확인하지 못했으나, 파괴된 세포로 생각되는 작은 입자들을 관찰하였다. 바지락 치패에 섬모류인 M. rubrum과 미소조류인 Isochrysis galbana (KMCC H-2)를 공급하면서 28일 동안 사육한 결과, 작은 치패 그룹(각장 0.46 mm)에서는 I. galbana를 공급한 실험구가 좋은 성장을 보였던 반면, 큰 치패 그룹(각장 0.84 mm)에서는 M. rubrum을 공급한 실험구가 I. galbana를 공급한 실험구에 비해 성장이 좋았다. 따라서 이 광합성 섬모류는 이매패류의 치패 및 모패와 입이 작은 자어의 먹이생물, rotifer의 영양강화제 및 어류의 천연 착색제로도 활용할 수 있는 잠재력이 있어 해양 생물공학적 활용을 위한 생물재료로서 개발 가능성을 제안한다.

• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.119-125
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• 2016

This study describes results on sexual maturation and characteristics of natural spawned eggs to develop a method for the production of stable, healthy fertilized eggs from captive-reared yellowtail kingfish, Seriola lalandi. A total of 59 yellowtail kingfish were captured off the coast of Jeju Island, after which the broodstock was cultured in indoor culture tank ($100m^3$) until they were 6.1-14.9 kg in body weight. As part of the rearing management for induced sex maturation, the intensity of illumination was maintained at 130 lux. The photoperiod (light/dark; L/D) was set to a 12 L/12 D from October 2013 to January 2014, and 15 L/9 D from February 2014 to June 2014. Feeds comprised mainly EP (Extruded Pellets), with squid cuttlefish added for improvement of egg quality, and was given from April to June 2014. The first spawning of yellowtail kingfish occurred in May 3, 2014, at a water temperature of $17.0^{\circ}C$. Spawning continued until June 12, 2014, with the water temperature set at $20.5^{\circ}C$. Time of spawning was 26 times at this period. The total number of eggs that spawned during the spawning period was $4,449{\times}10^3$. The buoyant rate of spawning eggs and fertilization rate of buoyant eggs during the spawned period were 76.1% and 100%, respectively. The diameters of the egg and oil globule were $1.388{\pm}0.041mm$ and $0.378{\pm}0.029mm$, respectively, which was higher in early eggs than in those from late during the spawned period.

• 한국양식학회지
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• 제19권3호
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• pp.205-209
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• 2006

현재 우리나라에서 종묘방류량이 많은 넙치의 유전적 다양성을 파악하기 위하여 양식산 어미 암컷 31마리, 수컷 52마리로 총 83마리로부터 생산된 종묘의 유효어미수와 근교계수를 microsatellite DNA marker 7개를 이용하여 추정하였다. 어미집단과 종묘집단의 대립유전자수는 어미집단에 비하여 하루 동안 채란한 E1 종묘집단에서 23.5%가 감소하였고, 이틀 동안 채란한 E2 종묘집단에서는 17.6%가 감소하였다. 유전자 동일성검사 결과, 산란에 관여한 어미수는 E1 종묘집단에서 총 23마리였으며 이중 암컷 9마리, 수컷 14마리였고, E2 종묘집단에서는 35마리로 암컷 15마리, 수컷 20마리였다. 유효 어미집단크기(Ne)를 추정하기 위해 산란에 관여한 실제 어미의 암수의 비율을 보정하면, Ne는 E1 종묘집단에서 21.9마리, E2 종묘집단에서 34.3마리로 추정되었다. 이에 따라 근교계수는 El 종묘집단이 0.023, E2종묘집단은 0.015로서 E2종묘집단에서 낮게 나타났다. 이와 같은 결과는 수산생물의 다양성을 보존하기 위한 FAO의 권고 기준보다 높게 나타남에 따라 유전적 다양성을 향상시키는 방류용 종묘생산 방안이 필요할 것으로 나타났다.

• 한국어류학회지
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• 제20권4호
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• pp.248-254
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• 2008

우리나라의 주요 양식 대상종인 넙치에 있어 유전적 조성에 대한 고려없이 구성된 양식 넙치 어미 집단에서 세대의 경과에 따른 집단의 유전적 다양성의 변화를 알아보기 위하여 총 8개의 microsatellite DNA markers를 이용하여 분석하였다. 동일한 수정란 생산업체에서 2003년에 생산된 양식 넙치와, 동일한 집단내에서 생산된 넙치로 어미 그룹이 완전히 교체된 2006년 및 2007년에 생산된 넙치 집단을 비교한 결과, 대립유전자 수와 이형접합기대치의 비교에서 2003년산 집단의 경우 9.75개와 0.796에서 2006년 7.78개와 0.785로 유전적 다양성이 다소 감소되는 경향이었다. 또한 대립유전자의 빈도에 있어서도 몇몇 대립유전자의 경우 소실되거나 빈도에 변화를 보이는 등 왜곡되어 나타났다. 그러나 여러 가지 다양성 지표들에서 수치상 감소를 나타내고 있는 이러한 결과들은 비록 유의적인 수준에서 유전적 다양성의 축소라고는 판단되지 않지만 양식 넙치 집단이 HWE에 어긋나 있어 세대가 진행될수록 집단의 유전적 다양성은 감소될 것으로 예상되었다.