• 한국수산과학회지
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• 제54권1호
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• pp.124-128
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• 2021

This study was conducted to evaluate the effects of incubation methods and transfer timings on the hatching rate of fertilized eggs of the river puffer Takifugu obscurus. Four incubation methods were tested, a) control (fertilized eggs attached to the glass plate), b) bottom (fertilized eggs spread on the bottom of the tank without any treatment), c) S-bottom (removing the stickiness of the fertilized eggs, and then spreading the eggs on the bottom of the tank), and d) incubator (removing the stickiness of the fertilized eggs, and then incubating the eggs in an incubator). Additionally, four transfer timings were tested: a) control (no transfer from the incubation tank), b) zygote (fertilized eggs transferred at the zygote stage), c) segmentation (fertilized eggs transferred at the segmentation stage), and d) pharygula (fertilized eggs transferred at the pharygula state). The results showed that the hatching rate of incubator was significantly higher than those of control, bottom, and glass (P<0.05). The results also showed that the hatching rates of control and pharygula were significantly higher than those of zygote and segmentation (P<0.05).

• 한국수산과학회지
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• 제42권1호
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• pp.63-67
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• 2009

The effects of adhesive substrates and bottom materials on the release of fertilized eggs by the Pacific cod, (Gadus macrocephalus) were examined to find an effective release method. Palm twin as an adhesive substrate displayed a significantly elevated adhesive rate compared to gulf weed. However, the survival rate of the fertilized eggs attached to palm twin was as low as 17.5% 8 days after fertilization (DAF). In contrast, fertilized eggs in the absence of adhesive substrate displayed the highest survival rate (47.0%). Concerning bottom materials, the survival rate of fertilized eggs on sand was significantly high (approximately 51.1%) on 8 and 9 DAF. The observations indicates that adhesive substrates are not needed and spawning ground bottom materials such as sand or mud should be considered when releasing fertilized eggs of Pacific cod.

• Environmental Analysis Health and Toxicology
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• 제17권1호
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• pp.13-19
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• 2002

Effects of Formalin treatment on embryogenesis and larvae growing in fertilized eggs and hatched larvae of olive flounder, Paralichthys alivaceus were investigated. Fertilized eggs and hatched larvae were exposed to aqueous solution with 100, 200, 400, 800 and 1,000 ppm of nominal formalin concentration. They were kept in sea water of 16, 18 and 22$^{\circ}C$, respectively. Survival rate and hatchability of fertilized eggs were high in control groups more than formalin treated groups in 16, 18 and 22$^{\circ}C$, respectively (P<0.05). A similar effect that survival rate of hatched larvae was also observed for control and treatment groups. On the other hand, fertilized eggs treated with 400 ppm formalin, were all death in kept in 22$^{\circ}C$. These results suggest that high-dose of formalin in fertilized eggs and hatched larvae in olive flounder, Paralichthys olivaceus was inhibited the normal embryogenesis for fertilized eggs and growing for hatched larvae. Also, these inhibited effects was promoted in higher temperature.

• Environmental Analysis Health and Toxicology
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• 제17권1호
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• pp.1-6
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• 2002

Effects on nonylphenol (NP) treatment on early development of fertilized eggs and survival of larvae in olive flounder, Paralichthys olivaceus were investigated. Fertilized eggs and hatched larvae were exposed to aqueous solutions of NP at nominal concentrations of 50, 100, 150 and 200 $\mu\textrm{g}$/L. In the control I and II (methanol-carrier control) groups, the hatchability of fertilized eggs were 90.7$\pm$7.02 and 90.0$\pm$5.29％ (P <0.05), respectively. However, treatments of NP concentrations at 50, 100, 150 and 200 ug/L were reduced to 78.7$\pm$4.16, 46.0$\pm$9.17, 48.0$\pm$3.46 and 33.3$\pm$11.02% (P<0.05), respectively. The time to hatching of fertilized eggs was delayed in high-dose NP treatment groups rather than control groups. Fertilized eggs of NP immersed group could not hatch normally, and also vertebra of the larvae observed as abnormal shape. Cumulative mortality of hatched larvae after 26hr NP treatment was 38.3, 78.3, 88.3 and 100% in NP 50, 100, 150 and 200 ug/L treatment groups, respectively. Whereas, control I and II were 11.7, 16.7% (P<0.05). Hatched larvae showed most death at the embryonic development stage with abnormalities. These results suggest that NP treatment in fertilized eggs and larvae was inhibited as normally development for fertilized egg and growing of larvae.

• International Journal of Industrial Entomology and Biomaterials
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• 제16권1호
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• pp.1-5
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• 2008

The present study was carried out with the aim to evaluate the viability of layings (delivery of fertilized and unfertilized eggs) with egg laying duration of elite bivoltine races. The temporal aspect of mating in terms of egg layings duration may also have impact on the number of eggs laid, pattern of egg laying and their viability. After different interval of egg laying duration, moth of Bombyx mori are removed from oviposition site after they have completed egg laying. Present investigation confirmed that there are no significant difference in relation to the occurrence of viable (fertilized) and non viable (unfertilized) eggs and duration of oviposition. Percentage of unfertilized eggs varied from 2.41 to 3.42% in case of CSR-3, 2.59 to 3.62% in case of CSR-6, 2.82 to 3.66% in case of CSR-16 and 2.58 to 3.40% in case of CSR-17 in different treatments. The occurrence of unfertilized eggs are also not significant in the different treatments specially in those eggs which were laid 24 hours after oviposition and kept for 4 months hibernation schedule.

• Applied Microscopy
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• 제26권3호
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• pp.277-291
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• 1996

The structures of the egg envelope in fertilized eggs of three species of characidae, head and tail light fish (Hemigrammus ocellifer), black tetra (Gymnocorymbus ternetzi), and buenos aires tetra (Hemigrammus caudovittatus) were studied using light and electron microscopes. The fertilized eggs in all species were colorless, transparent, spherical and non-floted type. The egg envelopes have a single micropyle resembling the pathway of sperm in the area of the animal pole. The micropyle was surrounded by protruded lines of the egg envelope in a radiated form. Egg envelopes of fertilized eggs in both head and tail light fish and buenos aires tetra consisted of three distinct layers; an outer layer, a middle layer and an inner layer. And that of blacktetra consisted of two layers; an outer layer and an inner layer. Also, an outer layers of both head and tail light fish and black tetra were adhesive types but, in that of buenous aires tetra was non-adhesive type. An outer surface of egg envelope in black tetra was arranged by pores regularly. In that of head and tail light fish and buenos aires tetra have a rough side. An inner layer of egg envelope in fertilized eggs consisted of lamellae alternating with interlamellae of lower electron density; an inner layer of fertilized eggs in head and tail light fish consisted of three layers, that of black tetra was four layers, and that of buenos aires tetra was five layers.

• Applied Microscopy
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• 제45권3호
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• pp.144-149
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• 2015

Nothobranchius guentheri and Nothobranchius patrizii have special life cycle to sustain the dry season. So, we investigated the fertilized eggs morphology, and compared ultrastructures of surface structures and the cross section of fertilized egg envelopes using light and electron microscopes to determine whether these fertilized eggs and egg envelopes show the species specificity or have special structure to sustain the dry season. These fertilized eggs were spherical, yellowish, demersal and adhesive, and had a one-sided large oil droplet. The whip-like structures, adhesive filament were distributed throughout egg envelope in both species. But, that of N. guentheri was covered with fibrous structures, and that of N. patrizii was smooth. The egg envelope consisted of two distinct layers: an outer, electron-dense layer containing adhesive filaments and an inner layer of 16 to 17 horizontal electron-dense lamellae alternating with 15 to 16 interlamellae of lower electron density in both species. The external shapes of fertilized egg and section of fertilized egg envelope were same, but ultrastructure of adhesive filaments on the outer surface was concluded to show species specificity. Our data indicate that the ultrastructural differences of adhesive filament and outer surface of fertilized egg envelope show species specificity although these species belong to same genus.

• 한국수정란이식학회지
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• 제30권3호
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• pp.207-211
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• 2015

미세주입법에 의한 형질전환 마우스 제작에는 대량의 전핵기란을 필요로 한다. 본 실험에서는 심플한 형질전환 마우스 제작방법을 확립하기 위해 초급속 동결한 전핵기란을 공시했다. 초급속 동결법으로 동결한 전핵기 체외수정란 139개를 융해 후 공시하고, ${\beta}-actin/luc^+$ 융합유전자를 미세주입하였다. 주입 조작 후, 형태학적으로 정상적인 수정란 101개(72.6%)를 5마리의 수란암컷 마우스에 이식하였다. 그 결과, 이식한 모든 마우스가 임신하고, 최종적으로 15마리(14.8%)의 산자가 태어났다. 한편, 450개의 체외수정란에 대해 동일한 배아조작 후에 338개(75.1%)가 생존하고 14마리의 수란암컷 마우스에 이식 하였다. 그 중에 78%의 수정암컷 마우스가 임신하고, 54마리(19.1%)의 산자가 태어났다. 태어난 산자에 대해서는 southern blot 법에 의해 염색체 내의 도입유전자의 도입을 확인한 결과, 동결수정란 처리구와 체외수정란구에서 각각 6.6%(1/15), 5.5% (3/54)의 마우스에서 도입유전자의 도입이 확인되었다. 더욱이 두 처리구 전부의 형질전환 마우스의 미부조직에서 도입유전자인 루시페라제 유전자의 발현이 관찰되었다. 이상의 결과에 의해 체외수정란 초급속 동결보존법을 사용한 Tg 마우스 제작방법의 확립을 확인하였고, 이러한 결과들로부터 실험기간의 단축과 작업의 간소화에 크게 이바지할 것으로 사료된다.

• Applied Microscopy
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• 제50권
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• pp.13.1-13.7
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• 2020

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of Ancistrus cirrhosus belong to Loricariidae using light and electron microscopes. The fertilized eggs formed a mass on the spawning place and were yellowish, spherical, non-transparent, demersal, adhesive, and a narrow perivitelline space. But, the adhesiveness of fertilized eggs was disappeared after spawning excluding contact parts. The micropyle with funnel shape was surrounded by 15-19 furrow lines of egg envelope in a spoke-like pattern. The outer surface of egg envelope has smooth side and inner surface of egg envelope was rough with grooves. Also, the total thickness of the fertilized egg envelope was about 32.58 ± 0.85 ㎛ (n = 20), and the fertilized egg envelope consisted of three layers, an outer adhesive electron-dense layer, a middle layer with low electron density and an inner electron-dense layer with grooves in counter structure from other most teleost. Collectively, these morphological characteristics and adhesive property of fertilized egg, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity.

• 한국발생생물학회지:발생과생식
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• 제24권1호
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• pp.19-30
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• 2020

The pH of water is one of the main environmental factors exerting selective pressure on marine and freshwater organisms. Here, we focus on the influence of pH on an organism's ability to maintain homeostasis and investigate the effects of acidification on immunity-related genes and osmotic pressure during early development of the olive flounder, Paralichthys olivaceus. The aim of our study was to determine the influence of various pH levels on the fertilized eggs and larvae of P. olivaceus. Gametes of P. olivaceus were artificially introduced and the resulting fertilized eggs were incubated at pH 4.0 (low), 6.0, and 8.0 (equivalent to natural sea water; control). We found that all eggs sank from the water column at pH 4.0. After 38 h, these eggs showed slow development. Hatching occurred more slowly at pH 4.0 and 6.0 and did not occur at all at pH 4.0. Result of gene expression, caspase and galectin-1 were expressed from the blastula to pre-hatch stages, with the exception of the two-cell stage. HSP 70 was also steadily expressed at all pH levels over the five days. The osmolality of fertilized eggs differed marginally at each stage and across pH levels. So, this results demonstrates that low pH level is detrimental to P. olivaceus fertilized eggs.