• Clinical and Experimental Reproductive Medicine
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• 제32권4호
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• pp.337-346
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• 2005

Objective: The oligosaccharide moieties of glycoproteins and proteoglycans have a vital function in blastocyst differentiation. Concanavalin (ConA), a lectin, is known to bind on the preimplantation embryos, especially on blastocyst. In this study, we investigated whether ConA can modulate the trophoblast development and about the regulating mediator. Also, we investigated whether expansion is enough for hatching procession of the mouse blastocyst. Method: Embryos were collected at 72 h post hCG injection and chemicals were treated after 24 h (96 hr post hCG injection). ConA or calcium ionophore A23187 were exposed to blastocyst and than analysis the developmental process for 48 hr. Intracellular free-$Ca^{2+}$ concentration in trophectoderm was measured with confocal laser microscope after exposing to ConA or calcium ionophore A23187. ConA-pretreated blastocyst exposed to the calcium ionophore A23187 and then analyzed the developmental process. Otherwise ouabain was treated to the blastocyst to block the $Na^+/K^+$-ATPase activity. Results: In contrast to the control blastocyst, the ConA-exposed blastocysts developed beyond the expansion stage with significantly high rate (90.4%) at 12 h post administration. ConA induced an increase the intracellular $Ca^{2+}$ concentration in trophectoderm. Calcium ionophore A23187 also stimulated expansion of blastocyst. Most of the control blastocysts developed to the hatching stage at 144 h post hCG injection. However, strongly 65% of the ConA-exposed embryos were arrested at expanded stage at same time point. The developmental progression rates to hatching stage of both ConA- and calcium ionophore A23187-expose blastocysts were significantly lower than that of the control. However ConA-pretreated embryos developed to the hatching stage like control embryos. Ouabain showed a tendency to delayed the progress to expansion stage but did not inhibit the development to the hatching stage. Conclusion: ConA-mediated expansion is the result of the increase of intracellular free-calcium in blastocyst stage embryo. It is suspected that expansion of the blasocyst is a essential indirect factor in hatching and the calcium may triggering the cellular mechanisms for the both expansion and hatching progression.

• Clinical and Experimental Reproductive Medicine
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• 제26권2호
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• pp.185-192
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• 1999

The present study was performed to investigate the efficacy and safety of laser assisted hatching (AH) on mouse embryos. Non-contact $1.48{\mu}m$ diode laser system used to create a precise hole on zona pellucida. 2-cell embryos were collected from the mice (ICR) that had the coitus vaginal plug confirmed at 48 hours after hCG injection. Collected 2-cell embryos were cultured in the HTF medium supplemented with 0.4% BSA. For experiments, embryos at 8-cell stage were used after 18-22 hours in culture. After assisted hatching, the embryos were further cultured in HTF medium containing 0.1% PVP (anti-hatching system) for 3 days. For evaluate efficiency of laser on mouse embryo hatching, the effect of AH methods (acidic tyrode, pronase and laser), the number of artificial holes (1, 2 and 3 hole) and the irradiation time of laser (2, 4, 6, 8 and 10 ms) were examined. Hatching rates of laser AH group (95.2%) was significantly higher than that of control group (50.8%), but there was no differences among the laser (95.2%), acidic tyrode (100%) and pronase (98.5%) groups. Hatching rates of the number of zona pellucida opening by laser, there were no differences among the 1 hole (87.5%),2 hole (92.1%) and 3 hole (85.9%) groups. Developmental and hatching rates of embryos according to laser irradiation time were similar in the treatment groups. Therefore, these results suggest that laser AH using non-contact $1.48{\mu}m$ diode laser is a simple and accurate and effective procedure for AH. Based on these results, laser AH could be use safely for human ART program.

• 한국발생생물학회지:발생과생식
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• 제14권1호
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• pp.27-34
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• 2010

A fertilized oocyte can get the competence for implantation through cleavage and stage-specific gene expression. These are under the control of autonomous and exogenous regulators including physiological culture condition. Endogenous and exogenous growth factors are considered as critical regulators of cleaving embryos during travel the oviduct and uterus. In this study, an effort was made to evaluate comprehensively the quality of embryos for implantation, grown in media enriched with EGF and PAF. The study evaluated developmental rates on given time, blastulation and hatching rates, and adhesion rates. Developmental rates of blastocyst to the hatching stage were significantly high in PAF treated group compared to the control in a dose-dependent manner but not in EGF group. Implantation rates were significantly high both PAF and EGF in a dose-dependent manner. H7, a PKC inhibitor, blocked the process of hatching of the blastocysts but combined treatment of EGF and PAF enhanced the hatching and implantation of blastocsyts. Based on these results it is suggested that EGF and PAF support acquirement of implantation competence at blastocyst stage through a PKC pathway.

• 한국수산과학회지
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• 제53권4호
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• pp.486-491
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• 2020

This study was investigated the survival and hatching rate of fertilized eggs in olive flounder Paralichthys olivaceus at water temperature, salinity, duration of transport and different stock densities during commercial transport. The observed optimal temperature during transport was 17.5℃ similar to the natural environmental conditions. The proper salinity was observed to be at 33 psu (practical salinity unit) in both surviving and hatching rate. In terms of the duration of transport, there were no differences until 12 hours between survival and hatching rate, but shorter time of transport would be better. With the best conditions during transport, 20,000 eggs/L were handled in both survival and hatching rate. These results can be essential in the production and transport of healthy olive flounder seeds.

• 한국양식학회지
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• 제10권4호
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• pp.473-483
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• 1997

붉바리 자어의 생존률 향상을 위한 연구의 일환으로써 자어의 주 사망 시기인 부화 직후부터 약 일주일간 자어의 난황흡수 및 먹이와 관련한 생존 특성 등을 조사하였다. 난황흡수 초기인 부화후 24시간 동안 자어의 난황 및 유구 흡수율은 난황보다는 유구의 경우가 더 높은 것으로 나타났다. 난황 및 유구의 흡수 시간은 수온이 높을수록 짧아지는 경향을 보였다. 수온 23-$25^{\circ}C$에서 99% 이상의 난황 및 유구가 흡수된 시점은 부화후 각각 84, 96시간이었고,$27^{\circ}C$에서는 각각 72, 84시간, 29-$31^{\circ}C$에서는 공히 부화후 60시간으로 나타났다. 수온 23-$31^{\circ}C$의 범위에서 수온(X)에 따른 자어의 개구시(Y)은 Y=-2.53X+118.4, ($r^2$=0.89)의 직선식으로 나타났다. 난황이 대부분 흡수되고 외부 영양섭취를 시작하는 시기 전후인 부화후 72-96시간째 자어의 상악장은 0.113-0.114 mm였으며, 개구후부터 부화후 1주일까지의 전장(X)과 상악장(Y)과의 관계는 Y=0.139X-0.165, ($r^2$=0.88)의 식으로 나타났다. 자어의 소화관에서 최초로 rotifer 가 발견된 때는 부화후 72시간으로써 99% 이상의 난황을 흡수한 시점이었다. 난황 및 유구를 완전히 흡수한 부화후 96시간에는 전체 자어중 약 33%가 먹이를 섭취한 것으로 나타났다. 첫 먹이 공급시기 지연에 따른 자어의 생존률은 부화후 84시간 이전까지는 첫 먹이공급 시기를 빨리할수록 생존율이 높은 것으로 나타났으나, 부화후 96시간에 첫 먹이를 공급한 경우는 부화후 120시간 째까지 모든 자어가 사망한 것으로 나타났다.

• 한국응용곤충학회지
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• 제29권1호
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• pp.20-24
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• 1990

사과나무 응애류의 월동밀도와 사과응애난의 부화시기와 부화율 그리고 응애류의 발생소장을 '87년부터 '89년사이에 경북지방 사과원에서 수행한 결과는 다음과 같다. 응애류의 월동밀도는 사과응애난은 군위, 안동, 칠곡지방에서는 모두 높았으나 남쪽지역인 경주지방에서는 아주 낮았다. 점박이응애의 월동성충은 조사지역 공히 밀도가 높았으며 주로 사과나무 내부조피에서 월동하고 있었다. 사과응애의 지역별 부화시기 및 부화율을 보면 부화개시일은 4월 14얼이었으며 부화종료일은 5월 3일이었다. 부화율은 지역간 차이가 없었으며 평균 89.3%였다. 응애류의 발생소장 조사결과 사과응애(Panonychus ulmi) 사과잎이 전개되면서 부화하여 5월 상순부터 7월 중순까지 우점하였으며, 점박이응애(Tetranychus urtcae)는 6월 중순부터 밀도가 급격히 증가하여 7월 이후에는 점박이응애가 우점종 이었다.

• 한국양식학회지
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• 제9권4호
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• pp.339-344
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• 1996

한국산 rotifer, Brachionus plicatilis 내구란의 부화에 미치는 온도($24\~36^{\circ}C$)와 염분($5{\~}30$ ppt)의 영향을 조사하였다. 가장 높은 내구란의 부화율은 $28^{\circ}C$, 15 ppt에서 $85.7{\%}$로 나타났다. 온도 $32^{\circ}C(42.6\~60.5\%)$와 $36^{\circ}C(52.0\~61.4\%)$에서는 염분과 수온에 따른 부화율은 유의적인 차이를 보이지 않았다. 부화시간은 온도가 높을수록 짧게 나타났다. $5^{\circ}C$ 암흑상태로 내구란을 보존할 경우 2일 동안 일시적으로 부화하였다. 그러나 $28^{\circ}C$ 내구란을 보존한 경우, 14일 동안 산발적으로 부화하였다. 또한 부화율은 $28^{\circ}C(58.1\%)$가 $5^{\circ}C(40.2\%)$ 보다 높게 나타났다. 내구란의 건조온도가 시간에 따른 부화율은 $30^{\circ}C$에서 1시간동안 건조한 내구란이 $46.4{\%}$로 가장 높은 부화율을 보였다.

• 한국응용곤충학회지
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• 제46권2호
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• pp.295-302
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• 2007

천잠의 연중 실내사육법을 확립하고자 천잠의 의잠절식, 수시부화 및 최청법을 조사하였다. 천잠의 일시소잠을 위하여 의잠을 절식 실험한 결과, $25^{\circ}C$ 와 $5^{\circ}C$ 에서 1일간 보호한 4령기잠기 생존율이 각각 83.3% 및 96.0% 로 의잠 절식기간의 보호온도가 낮을수록 생존율이 높았다. 연중 다회사육을 위해 수시부화실험을 한 결과, 천잠알을 2개월 냉장할 경우에는 $5^{\circ}C$가 좋았으나 6개월 이상 냉장하여 사용할 경우에는 $2.5^{\circ}C$또는 $0^{\circ}C$에 보호하는 것이 실용부화비율이 높은 것으로 나타났다. 또한 일시부화에 적합한 천잠알의 보호조건을 조사한 결과, 관행적 최청방법 ($25^{\circ}C$ 보호)으로는 5-6일 걸리는 천잠알의 부화가 $15^{\circ}C$ 예비최청과 암최청 방법의 도입으로 2일간에 80% 가 부화하는 좋은 성적을 얻을 수 있었다.

• Fisheries and Aquatic Sciences
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• 제8권4호
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• pp.228-234
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• 2005

Despite the relatively high production of fingerlings of the olive flounder Paralichthys olivaceus, its larval rearing in terms of first feeding has not been fully analyzed. We evaluated the variations of amino acids and fatty acids of starved larvae over 96 hr after hatching. We also investigated depletion of the yolk and oil globule of starved larvae and those fed the rotifer Brachionus plicatilis. In addition, the optimum size of the rotifers according to the mouth size of the larvae, and the point of no return with delay of the first feeding, were also examined. The amino acids in the egg decreased abruptly during embryo development. At 48 to 72 hr after hatching, the amino acids of starved larvae decreased by $30-40\%$ from the level in newly hatched larvae. The concentrations of fatty acids in newly hatched larvae were lower than those of floating eggs and dropped sharply at 48 hr after hatching, when the yolk disappeared. The starved larvae depleted their yolksacs and oil globules earlier than the fed larvae did. At 84 hr after hatching, rotifers were detected for the first time in the guts of the larvae, which were about 3 mm in total length. The point of no return appeared to be close to the fourth day from the first feeding. For a high survival rate of P. olivaceus larvae, the first feeding should occur before the third day after hatching.

• Fisheries and Aquatic Sciences
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• 제21권9호
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• pp.23.1-23.8
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• 2018

Background: Russian sturgeon (Acipenser gueldenstaedtii) is an emerging candidate species in the Korean aquaculture domain owing to its highly valued caviar. Although the embryonic development of this species was previously described, the complete image data on the morphological differentiation of developing embryos have not been yet fully available. Further, with the viewpoint of larval production in hatchery, the effects of temperature on embryonic viability and the temporal window of hatching event have not been extensively studied. Hence, the objective of this study was to provide a complete set of photographic image data on the embryogenesis and also to examine the effects of incubation temperatures on embryonic viability and hatching event in farm-bred Russian sturgeon. Results: Typical characteristics of embryonic development including uneven, holoblastic cleavages with unequal blastomeres, followed by the formation of germ layer, neurulation, and organogenesis until hatching, were documented. Under different temperature conditions (12, 16, or $20^{\circ}C$), viability of embryos incubated at $12^{\circ}C$ was significantly lower as relative to those of 16 and $20^{\circ}C$ incubated embryos. Hatchability of embryos was higher, and the timing of hatching event was more synchronized at $20^{\circ}C$ than at 12 and $16^{\circ}C$. Conclusion: Data from this study suggest that the incubation of Russian sturgeon embryos at $20^{\circ}C$ would be desirable in the hatchery practice with respect to the good hatchability of embryos and the synchronization of hatching events. Additionally, the updated image data for complete embryonic development could be a useful reference guide for not only developmental researches but also artificial propagation of Russian sturgeon in farms.