• 한국가축번식학회지
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• 제4권1호
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• pp.75-82
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• 1980

This experiment was carried out to improve a simple and effective procedure of egg transfer which is considered to be the most useful technique for the improvementand proliferation of domestic animals. Several experiment procedures such as superovulation, surgical recovery of ovulated egg, in vitro capacitation of ejaculated spermatozoa, in vitro fertilization and culture of embryo were conducted. The results obtained in this experiment were summarized as follows: 1. In rabbits treated with PMS in combination with estradiol and HCG, 10 to 43 eggs were obtained in one rabbit and the average ovulation number of 20 rabbits was 21 eggs. 2. Six to 24 eggs (average 13 eggs) were recovered from the removed oviducts by the methods of flushing technique and the average recovery rate of 20 rabbits was 61.9 percent. 3. Most rabbit spermatozoa ejaculated by artificial vagina were capacitated in vitro by the culture of the spermatozoa with PBI medium at 37$^{\circ}C$ for 4 hours after removal of seminal plasma. 4. Normal fetilization following in vitro fetilization was observed in 88 (42.7%) of 206 eggs. 5. The number of eggs developed to 2-, 4-, and 8-cell stage following in vitro culture with PBI medium at 37$^{\circ}C$ was 26 (70.3%), 20 (54.1%) and 17 (45.9%) of 37 eggs used for in vitro culture.

• 생명과학회지
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• 제6권3호
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• pp.171-177
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• 1996

It was carried out to find the carbohydrate metabolism for the glycogen utilization and the effects of low temperature(1$\circ$C, 5$\circ$C)on embryonic development of the silkworm, Bombyx mori L. The content of sorbitol and glycerol in the chillihg eggs stored at 5$\circ$C or 1$\circ$C on 24 hours after oviposition showed the highest level on the 50th day. After that, the corresponding value in the eggs stored at 5$\circ$C were decreased, and the value in the eggs stored at 1$\circ$C maintained the similar level. The trehalose level was rapidly increased on 50$\sim$60th day or thereabouts, and then, it was accumulated. When the eggs stored at low temperature were tranaferred and developed the embryo at 25$\circ$C, sorbitol and glycerol were respectively changed to glycogen. Futhemore, the content of trehalose and glucose showed specific of patterns with each embryonic stage at low temperature. With the aforementioned results, the intemediary metabolism of carbohydrate was discussed with regard to embryonic development of non-diapause eggs of silkworms.

• Animal cells and systems
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• 제8권2호
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• pp.77-80
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• 2004

To investigate the effect of host egg color dimorphism on the vinous-throated parrotbill (Paradoxornis webbianus) - common cuckoo (Cuculus canorus) interactions, we monitored breeding nests of vinous-throated parrotbills, and conducted model egg experiments, using two colors: white and blue. Of the 190 nests examined in this study, cuckoo parasitism occurred at 10 nests (8 blue and 2 white egg clutches, respectively), and only blue cuckoo eggs were found. This frequency was similar to the egg-color ratio of all host nests found (151 blue and 39 white egg clutches). Vinous-throated parrotbills showed high rejection rate towards both cuckoo eggs and model ones. There was a significant difference in rejection rates towards mimetic (blue) and non-mimetic (white) eggs in blue egg clutches. Mimetic eggs put in nests took significantly longer to be rejected than non-mimetic ones. The most common rejection method used by the hosts was egg ejection (puncture-ejection). The costs of ejecting non-mimetic eggs tended to be lower than those of ejecting mimetic eggs. These results indicate that egg-color dimorphism in this species favors the individuals having white egg clutches in terms of higher rejection rate and lower ejection costs of the parasitic eggs. This study also suggests that egg-color dimorphism of the vinous-throated parrotbill decreases the effect of cuckoo parasitism on host populations.

• 한국수산과학회지
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• 제40권4호
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• pp.243-247
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• 2007

We investigated the reproductive behavior of Octopus minor, order Octopoda, class Cephalopoda under laboratory conditions. Each mature female octopus was kept in an aquarium with a plastic tube for shelter, and one mature male was introduced for the purpose of copulation. Before spawning, the female coated the roof of the shelter with a light-green material, upon which it then fixed its eggs one by one. This spawning behavior lasted 1 to 3 days. Fertilized females spawned 54 eggs on average, ranging from 21 to 112 eggs at 72 to 98 days after copulation. The attached eggs were 18.1-19.0 mm in length, 5.0-6.1 mm in width, and 0.30-0.38 g in weight. The mother octopods did not feed; they attended to the eggs by using their arms to rub the egg surfaces and used their funnel to blow sediments off of the eggs. At water temperatures of $20.9-21.5^{\circ}C$, the fertilized eggs hatched within 73 to 90 days after being spawned. The effective cumulative water temperature was $1,569-1,892^{\circ}C$. At the end of incubation, the body weight of the mother octopods was reduced to approximately 56% of the initial weight, and most mother octopods died soon after the young hatched.

• 대한수의학회지
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• 제23권1호
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• pp.105-110
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• 1983

The studies carried out to investigate the detection method of Fasciola eggs from positive cattle feces in the intradermal reaction method with laborsaving composition of sieves and Kim's sedimental tube method. The results obtained are summarized as follows: 1. The detection method of Fasciola eggs was improved by 3 meshes (100mesh, 150mesh, 250mesh) for filteration of fecal fluid contained Fasciola eggs. 2. Third type of tube in the 3 kinds of sedimental tube had the highest recovers rate of Fasciola eggs. Thus, this type of tube was selected and called as Kim's sedimental tube. 3. A-II, A-III, B-III and C-III type by Kim's sedimental tube method had the recovery rates of eggs in the 1st drop as ranged 99 to 100% and, A-I, B-II, C-II as 71 to 91%. 4. These Type of tubes were useful to detect Fasciola eggs and to shorten the time of the diagnostic procedures. 5. The Kim's sedimental tube method showed high recovery rates and convenient procedures as compared with other detection methods reported. In addition, the EPG value can also be obtained by this method. Therefore, it is desirable that the Kim's sedimental tube method could be recommended to clinicians.

• 환경생물
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• 제41권2호
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• pp.145-166
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• 2023

Parrots have been threatened by global trade to meet their high demand as pets. Controlling parrot trade is essential because parrots play a vital role in the ecosystem. Accurate species identification is crucial for controlling parrot trade. Parrots have been traded as eggs due to their advantages of lower mortality rates and more accessible transport than live parrots. A molecular method is required to identify parrot eggs because it is difficult to perform identification using morphological features. In this study, DNAs were obtained from 43 unidentified parrot eggs using a non-destructive sampling method. Partial cytochrome b (CYTB) gene was then successfully amplified using polymerase chain reaction (PCR) and sequenced. Sequences newly obtained in the present study were compared to those available in the GenBank by database searching. In addition, phylogenetic analysis was conducted to identify species using available sequences in GenBank along with sequences reported in previous studies. Finally, the 43 parrot eggs were successfully identified as seven species belonging to two families and seven genera. This non-destructive sampling method for obtaining DNA and molecular identification might help control the trade of parrot eggs and prevent their illegal trade.

• 한국축산식품학회지
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• 제43권6호
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• pp.1002-1016
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• 2023

This study aimed to develop appropriate temperature management practices and provide scientific evidence to support the development of sell-by-date guidance for eggs. Washed and unwashed eggs were subjected to storage under six different scenarios, and both types of eggs were stored at temperatures up to 35℃ to evaluate the sell-by-date. Despite temperature fluctuations or continuous storage at 30℃ for 5 days, subsequent storage at 10℃ resulted in significantly higher Haugh unit and yolk index on day 15. These results indicate that refrigerating eggs from retail sales until consumption is effective for egg quality management, despite the exposure of up to 35℃ during distribution. In terms of sell-by-date evaluation, washed eggs retained class B quality for an additional 37 days beyond the recommended sell-by-date at 15℃, which is above the regulated storage temperature. However, unwashed eggs maintained class B quality for approximately 20 days at 30℃-35℃, emphasizing the need for sell-by-date guidelines for unwashed eggs. This study is the first to provide appropriate egg-handling practices based on the actual distribution environment in Korea.

• 대한수의학회지
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• 제32권2호
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• pp.157-164
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• 1992

Changes in the both inward current and conductance of membrane by the fertilization were observed using the one microelectrode voltage clamp(or switch clamp) technique. Unfertilized eggs and both 1- and 2-cell stage eggs after fertilization were donated from the superovulated mouse (ICR, more than 6 weeks old) treated with PMSG(pregnant mare serum gonadotropin, Sigma) and HCG(human chorionic gonadotropin, Sigma) and naturally mated ones, respectively in this experiment. Membrane potential was held at -90mV and the voltage step was applied from -80mV to 50mV with interval of 10mV or 20mV for 300ms. since both of amplitudes and time courses in the membrane currents were various according to the states of cells and clamping condition, results were presented by their $averages{\pm}SEM$(standard mean error)and ratios or percentages. Inward currents began to appear in response to the step depolarization from -60mV and reached its maximum at -50mV. However, since the potential was not clamped evenly during the voltage step, current-voltage(I-V) relationship might be positively shifted 10 or 20mV. From the steady-state currents plotted in the I-V curve, outward rectification was markedly observed. Peak inward currents$(i_{in})$ at -50mV were $-0.62{\pm}0.23nA$(n=4),$-0.52{\pm}0.25nA$(n=5) and $-0.37{\pm}0.25nA$(n=6), in the 1-cell stage, 2-cell stage fertilized eggs and in the unfertilized eggs, respectively. Pure inward current (difference between steady-state and peak, $i_{in. pure}$) were $-1.01{\pm}0.23nA$, $-0.69{\pm}0.43nA$ and $-0.68{\pm}0.29nA$, respectively in the 1-cell stage fertilized eggs, unfertilized eggs and 2-cell stage fertilized eggs. These results suggested that the outward current in fertilized eggs of 2-cell stage was more increased than those in the unfertilized eggs. Pure inward currents in the all stages of eggs showed a similar fashion in the I-V relationship from -50mV to 50mV and reversal potential at 50mV. Time constant of inactivation$({\tau})$ in the inward current was decreased as the membrane potential was depolarized in the unfertilized and 2-cell stage eggs but in the 1-cell stage eggs t was not likely to be affected significantly. Slope conductances were 14.2nS, 8.9n5 and 7.7nS in the 1-cell, 2-cell stage fertilized eggs and the unfertilized eggs, respectively. Membranes between two cells within a zona pellucida seem to be electrical-connected in the 2-cell stage eggs from the observation made in the analysis for the electronic spread and decay to the current stimuli. Both of inward current and membrane conductance were increased after fertilization in the mouse eggs. Inward current seems to be carried by the same ion or through the same channels up to the 2-cell stage and ion that carried inward current was thought to play important function after fertilization in the mouse eggs.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.272-274
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• 2003

A few studies have examined the hatching response of copepod diapause eggs to various factors (Ban and Minoda, 1991; Chen and Marcus, 1997). Marcus (1979) monitored the hatching of diapause eggs of Labidocera aestiva and suggested that diapause eggs of marine copepods undergo a refractory phase similar to other diapausing organisms. (omitted)

• 한국가금학회:학술대회논문집
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• 한국가금학회 2004년도 제21차 정기총회 및 학술발표회
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• pp.35-36
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• 2004

난백의 높이와 하우유니트(HU)는 저장온도에 관계없이 저장기간이 경과할수록 감소되는 경향이 있었던 반면에 난백의 pH는 반대로 증가하는 경향이 있었다. 일반적으로 $3\;^{\circ}C$에서 저장되었던 계란들은 $10\;^{\circ}C$에서 저장된 계란들보다 HU는 더 높게 나타났던 반면에, 난백의 pH는 더 낮은 것으로 나타났다. 한편 통계적으로 유의한 차이는 아니었지만 무정란은 유정란에 비해서 저장온도에 관계없이 난백의 높이 및 HU는 더 높은 것으로 나타났고, $3\;^{\circ}C$에서 저장된 계란들의 난백의 pH는 무정란이 유정란보다 더 높았으나(P<0.05), $10\;^{\circ}C$에서 저장된 계란들의 경우는 유정란과 무정란간에 별 차이가 없었다. 난각강도는 유정란이 무정란보다 두 온도역 모두 유의하게(P<0.05) 더 컸었다. 그리고 암탉의 수정에 관계없이 난백의 높이와 pH는 부(-)의 상관관계(P<0.01~0.001)가 있었고, 난백의 높이와 HU는 정(+)의 상관관계(P<0.001)를 나타내었다. 이상의 결과를 종합해 보면, 난백의 높이 혹은 HU와 같은 계란의 신선도 변화에 있어서 상대적으로 암탉의 수정 유무보다는 저장기간과 저장온도가 더 중요한 요인인 것으로 사료되며, 일반적으로 저장온도가 낮을수록 HU는 증가되는 반면에 난백의 pH는 반대로 감소되는 것으로 보여진다.