• International Journal of Industrial Entomology and Biomaterials
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• 제18권1호
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• pp.1-7
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• 2009

Quality of seed in the mulberry silkworm, Bombyx mori (L.) is determined by many important factors, wherein unfertilized eggs play an important role. Unfertilization of eggs are caused by several reasons such as, abnormality in the sexual organs of the male and female, abnormal development of the micropylar end of the egg, unfavorable environmental conditions during spinning, cocoon preservation, imperfect handling of moths, mating, ovipostion, cold storing of pupae / moths and indiscriminate use of male moths etc. Though the presence of unfertilized eggs would in no way affect the fertilized ones and their quality directly, the frequency of their occurrence underrates the quality and brings down the hatching percentage. Lower the occurrence of unfertilized eggs, higher is the rating of seed quality. Of the various intrinsic and extrinsic factors and events involved in egg deposition of an adult silk moth, mating is an instinct and a biological obligation for the ultimate perpetuation of the species and a must to provide stimulus for oogenesis and bring about biochemical changes in the spermatophore of the silkworm in order to ensure the presence of sufficient number of normal sperms and testicular fluid in the female reproductive organ, activating ovulation and accelerating oviposition behavior and egg deposition. An attempt has been made in this article to briefly elucidate the characteristics of unfertilized eggs, causes of their occurrence and its impact as well as the significance in silkworm seed production.

• 수산해양기술연구
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• 제51권3호
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• pp.370-374
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• 2015

Pacific herring Clupea pallasii eggs were attached to the gill net in Korean coastal waters off Busan. To conservation and management the eggs attached to the gill net, we followed the natural hatching in coastal waters from five days after fertilization to the hatching finished, where the temperature was $9^{\circ}C$. The diameter of fertilized eggs was 1.24-1.55 mm (n= 50), and had a segmented pale yellow yolk, no oil globule. Natural hatching had started by 10 days after fertilization. Mass hatching occurred around 11-12 days after fertilization, most of eggs separated from the gill net. Therefore, when the Pacific herring eggs attached in gill net, should be natural hatching-induced in coastal waters during 12-14 days.

• Toxicological Research
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• 제14권3호
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• pp.379-384
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• 1998

Endocrine disruptor is an exogenous substance that changes endocrine function and causes adverse effects at the level of the organism, its progeny, and/or (sub)populations of the organisms. Purported adverse effects are cancers, declines in reproductive health, developmental learning disabilities in humans, and declining populations, altered morphology, physiology or behavior in wildlife. In these days, expert groups on chemicals in IPCS, IFCS and OECD are intensively discussing the identification of endocrine disruptors and the proper management of those chemicals. In this study, we screened the endocrine disrupting effects of lead using fertilized eggs of Oryzias latipes. In brief, the eggs were exposed to lead with different concentrations at Ringer's solution, and the mortality, the incidence of deformation, the body movement and the hatching success were determined after incubation. The histological analysis of normal and deformed larvae was also carried out. Compared to control, the mortality and the heart rate of eggs and/or larvae increased, but the hatching success and the tail movement decreased. The morphological observation showed the asymmetrical deformation of larvae and the distortion of spinal cord. The absorption of the liquid in yolk sac was hindered. The adverse effects of lead in the ontogeny of fertilized eggs of Oryzias latipes seemed to be stronger in pH5.6 than in pH7.5 solution. In summary, lead showed adverse effects on the ontogeny of fish fertilized eggs plays critical role in regulating biological systems and controlling developmental processes as an endocrine disruptor.

• 한국어병학회지
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• 제31권1호
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• pp.9-13
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• 2018

2017년 1월에서 4월까지 강원도 고성에서 사육중인 명태 친어로부터 수정란을 채집하여 신경괴사증바이러스(nervous necrosis virus, NNV)의 검출을 시도하였다. 매 회 50 mg씩 수정란을 채집하여 이를 1 set로 간주하였으며 총 37 set를 제작하였다. RNA를 추출하고 cDNA를 합성하여 NNV를 대상으로 reverse transcriptase PCR을 실시하였다. 그 결과, one-step PCR법으로는 37 set의 시료가 모두 음성이었으며, two-step PCR법으로는 5.4% (2/37)의 시료가 양성을 나타내었다. 그러나, band의 농도가 매우 낮아 시퀀싱은 불가능하였다. 본 연구의 결과 및 이전 연구의 결과로부터 현재 국내에서 양식하고 있는 명태에서 NNV 감염에 의한 폐사는 발생하지 않는 것으로 추정된다. 하지만, 지속적인 모니터링 및 양성 개체 출현 시 바이러스 분리의 시도 등은 필요할 것으로 생각된다.

• 한국수산과학회지
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• 제50권3호
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• pp.287-295
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• 2017

Egg development and morphological change of larvae of the Sakhalin sole Limanda sakhalinensis were studied by observing specimens obtained in a rearing experiment from fertilized eggs to the juvenile stage. The wild broodstock was collected in January 2010 and kept in a circular water tank (${\O}1.5{\times}1m$) at a temperature of $14.5{\pm}0.5^{\circ}C$. Fertilized eggs ranged from 0.72 to 0.82 mm ($0.77{\pm}0.07mm$, $mean{\pm}SD$) in diameter. The eggs were spherical, transparent and adhesive demersal. The egg yolk was divided from the oocyte 10 min after fertilization (AF), and an embryo was formed in 36 h AF. More than 50% of the eggs hatched within 133 h AF. The mouth and anus did not open until $3.5{\pm}0.25mm$ total length (TL). At 4, days after hatching (AH), the fish became larvae 3.7 to 4.2 mm ($4.0{\pm}0.36mm\;TL$), yolk absorption was completed and the mouth began to open. The left eye moved upward and the nostril moved to the right at 39 days AH. These post-larvae ranged from 8.0 to 9.9 mm TL ($8.9{\pm}1.33mm\;TL$). At 50 days AH, the fish became juveniles ($12.4{\pm}1.20mm\;TL$) There were 70-72 dorsal fin rays, 55-56 anal fin rays, 11 pectoral fin rays, and 6 ventral fin rays and the juveniles adopted a benthic life.

• 한국가금학회지
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• 제30권2호
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• pp.91-94
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• 2003

본 시험은 육용종웅계의 원정액과 동결정액을 이용하여 인공수정시 종란의 수정율에 미치는 영향을 비교ㆍ조사하여 동결정액의 산업화 적용 가능성에 대한 기초자료를 제공 하고자 실시하였다. 5 수의 로스 육용종웅계에서 얻어진 정액을 원정액 및 동결정액으로 처리하여 각각 30 수 씩의 육용종빈계에 인공수정하였다. 종란은 정액처리당 총 180개를 입란하였으며, 입란 후 10 일째에 검란하여 수정율 및 발육중지율을,21일째 부화율을 조사하였다. 동결정액에 의한 수정율 및 부화율은 68.0 및 47.1％로 이는 원정액처리구의 88.3및 87.2％ 보다 유의하게 낮았다. 또한 동결정액을 이용하여 인공수정을 시켰을 때에 무수정란수는 원정액을 사용하였을 때 보다 2.7 배 유의적으로 높았으며 발생중지란수도 3.2배 높았다(P<0.05). 원정액과 비교하여 동결정액을 이용한 인공수정시 보여준 높은 무정란수와 발생중지란수를 개선하기 위한 더 많은 연구가 필요하다고 사료된다.

• 한국수산과학회지
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• 제50권3호
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• pp.296-301
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• 2017

We conducted a study to 1) determine the indicators of gonadal maturity in male and female Korean walleye pollock Theragra chalcogramma for the purposes of artificial insemination; 2) establish the RNA/DNA ratio of mature eggs in this species; and 3) monitor the effect of refrigerated storage on egg viability and the motility of sperm collected from dead adult males. During the spawning season, the color of female gonads changed from orange to transparent, and that of male gonads changed from pale orange to milky white. The DNA content and RNA/DNA ratio of mature eggs were maintained without significant changes for approximately 6 h when eggs were preserved at $4^{\circ}C$. Sperm could be obtained from both milt and undiluted semen. Sperm obtained from milt ceased moving on the second day after isolation, while over 60% of sperm obtained from semen showed movement until the 13th day. Seven attempts were made to artificially inseminate mature eggs, of which two resulted in successful fertilization. The successful inseminations produced 94,000 and 5,000 fertilized eggs, respectively. This study shows that artificial insemination of walleye pollock is a viable strategy when natural propagation is not possible.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
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• pp.131.2-131
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• 1996

No Abstract, See Full Text

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2001년도 제41차 추계학술대회
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• pp.118.2-118.2
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• 2001

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2002년도 제42차 춘계학술대회
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• pp.86-86
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• 2002