• Korean Journal of Animal Reproduction
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• 제20권4호
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• pp.385-393
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• 1997

다세포 생물에서 몸의 효율적 생존을 위한 각 기관의 homeostasis는 세포 증식과 사망에 의해 조절된다. 따라서, apoptosis라 명명된 세포사망은 정교한 기전에 의한 능동적이고 자발적인 사망기전으로써 몸의 정상적 유지를 위한 필수적인 현상이다. 발생기 세포나 신경세포 또는 흉선세포 분화 동안 과다한 세포의 제거가 apoptosis의 대표적인 예이며, 각종 호르몬에 의해 그 기능이 조절되는 난소세포에서도 apoptosis가 활발히 일어난다. Rat난소에는 태어날 때 수십 만개의 난포를 지니고 있는데, 이 중 단지 1%만이 배란에 사용되어질 뿐이고 나머지는 모두 사망하게 된다. 이러한 난포사망은 난소의 적절한 세포 수를 유지하기 위한 필수적 과정이며, 인위적으로 apoptosis를 억제하는 유전자인 bcl-2를 과다 발현시키면 난소암이 발생하는 연구결과가 이를 입증해주고 있다. 이처럼 중요한 난포 사망기전은 apoptosis라는 개념이 정립되면서 최근 들어 점차 그 연구가 활발해지고 있다. Apoptosis의 특징 중 뚜렷한 점은 DNA가 일정한 간격으로(180∼200 bp)잘려지는 DNA fragmentation현상으로, 이를 이용하여 DNA3'-end 부위에 방사선동위원소를 label한 후 이를 전기영동으로 분리하면 apoptosis를 손쉽게 측정할 수 있다. 난소의 기능은 시상하부호르몬인 LH와 FSH 뿐만 아니라 난소에서 분비되는 각종 난소국부호르몬들에 의해 조절된다. 특정한 발육단계의 난포는 특정한 호르몬에 의해 그 기능을 조절 받는데, 이러한 난소기능 조절기작은 매우 복잡한 경로를 지니고 있다. 이러한 복잡한 기작으로 인해 초기 연구에서첨 생체 내에서 밝히려는 연구 시도는 어려움에 부딪치게 되었다. 생체내 실험은 난소가 다양한 발육단계의 난포를 동시에 지니고 있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.

• Korean journal of applied entomology
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• 제62권3호
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• pp.117-124
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• 2023

The management of Ricania spp. is difficult because this pest has a wide host range and diverse habitats such as agricultural, suburban, urban, and forested areas. However, the researches for Ricania spp. management have been focused on only agricultural crops. Thus, it is required to determine the arboreal host preference of Ricania spp. at the surrounding areas of the farms to increase its management efficiency. To determine its host preference at arboreal plants, we reviewed the previous studies and investigated the densities of Ricania spp. at woody plants with high ecological importance but insufficiently studied. This study identified 120 species in 53 families of arboreal hosts of Ricania spp. Only Cornus officinalis and Styrax japonicus were preferred by all developmental stages of Ricania spp. The host preference of Ricania spp. was changed according to its developmental stages. This phenomenon would be caused by that each developmental stage of Ricania spp. would prefer different parts of woody plant, and require different nutrients for its survivor and reproduction. These results of this study could be helpful to make a plan of comprehensive management strategies for Ricania spp.

• Korean Journal of Environmental Agriculture
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• 제13권1호
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• pp.47-59
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• 1994

This study was conducted to estimate the growth stages(DVS) and plant developmental rate(DVS) of rape by using climatic data. Daily average air temperature and day length were analyzed in correspond to growth stages of rape. Each growth stage was clasified by seeding, heading, flowering maturing stage respectively. Growing days of each stage were closely related with average air temperature and accumulated air temperature. Plant development rate increased fastly in condition on high temperature and long day length. Especially winter season the DVR increased linearly. DVR fluctuated from 0 to 0.026 upto heading date. In stages from heading to flowering, and to maturing DVR showed in range 0.018-0.048 and 0.005-0.018 respectively. Prediction of plant growth stage has high correlation with obserbed value, r=0.772-0.948, most highest of them were from heading to maturing.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 한국농림기상학회 2001년도 춘계 학술발표논문집
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• pp.101-104
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• 2001

작물 발육단계의 정확한 진단은 그 시기의 생리적 반응을 이해하고 정확하고 정밀한 생육관리를 위해서 절대적으로 필요한 요소이다. 지금까지 벼의 발육단계 예측을 위한 모델에는 GDD를 이용하는 방법(이, 1972), 한 단계의 발육을 완료하는데 걸리는 기간(t)과 이 기간중의 평균기온, 평균일장의 단순회귀 또는 중회귀를 구하는 방법(Gao et al, 1989; Yin et al, 1995; 임, 1982), 평균발육속도(1/t)를 이 기간중의 평균온도와 평균일장의 함수로 표현해서 이를 적산하여 1이 되었을 때를 발육완료일로 나타내는 방법(이, 1987; 신 등, 2000), 발육기간이 시계열자료를 모두 고려하여 함수를 이용하지 않는 non-parametric 방법(이, 1991) 등이 있다.(중략)

• Korean journal of applied entomology
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• 제42권1호
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• pp.43-51
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• 2003

This study was carried out to develop the forecasting model of Pseudococcus comtocki Kuwana for timing spray. Field phonology and temperature-dependent development of p. comstocki were studied, and its stage transition models were developed. p comstocki occurred three generations a year in Suwon. The 1 st adults occurred during mid to late June, and the 2nd adults were abundant during mid to late August. The 3rd adults were observed after late October. The development times of each instar of p. comstocki decreased with increasing temperature up to 25$^{\circ}C$, and thereafter the development times increased. The estimated low-threshold temperatures were 14.5, 8.4, 10.2, 11.8, and 10.1$^{\circ}C$ for eggs, 1st+2nd nymphs, 3rd nymphs, preoviposition, and 1st nymphs to preoviposition, respectively. The degree-days (thermal constants) for completion of each instar development were 105 DD for egg,315 DD for 1st+2nd nymph, 143 DD for 3rd nymph, 143 DD for preoviposition, and 599 DD for 1 st nymph to preoviposition. The stage transition models of p. comstocki, which simulate the proportion of individuals shifted from a stage to the next stage, were constructed using the modified Sharpe and DeMichele model and the Weibull function. In field validation, degree-day models using mean-minus-base, sine wave, and rectangle method showed 2-3d, 1-7d, and 0-6 d deviation with actual data in predicting the peak oviposition time of the 1st and 2nd generation adults, respectively. The rate summation model, in which daily development rates estimated by biophysical model of Sharpe and DeMichele were accumulated, showed 1-2 d deviation with actual data at the same phonology predictions.

• Korean journal of applied entomology
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• 제50권3호
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• pp.185-194
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• 2011

Aliphatic cuticular hydrocarbons (CHCs) of different developmental stages of the spot clothing wax cicada, Lycorma delicatula (Hemiptera: Fulgoridae) were analyzed using GC and GC-MS. The numbers of carbons in the major CHCs of each developmental stage 32, 33, 28, 38, 37 in the egg, 1st, 2nd, 3rd, and 4th instar nymphal stages, and adults, respectively. The cuticle of Lycorma delicatula contains mainly methyl-branched 9-methylheptacosane (15.11%) in the egg stage, and a high proportion of n-heptacosane in nymphal stages (15.75, 22.42, 25.04, and 23.11 % in the 1st, 2nd, 3rd and 4th instars, respectively). In contrast, male and female adults had high proportions of n-nonacosane (13.42 and 16.55%). The chemical constituents of CHCs were classified into five groups (n-alkanes, monomethylalkanes, dimethylalkanes, trimethylalkanes, olefins) and group profiles of each developmental stage were compared. Egg surface was composed mainly monomethylalkanes (45.39%), a saturated hydrocarbon. Nymph CHCs consisted primarily of n-alkanes (37.63 to 46.12%). There was a difference between adult male and female CHCs. However, both contained n-alkanes and monomethylalkanes. CHCs with trimethyl or double bonded structure were rare in all stages.

• Parasites, Hosts and Diseases
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• 제23권2호
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• pp.189-196
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• 1985

In order to observe the protein composltlOns of soluble extracts of P. westermani, and their changes during early developmental stages, the crude saline extracts of 4, 6, 8, 10 and 12 week-old worms which were harvested from experimentally infected dogs were analysed by disc-PAGE. The results were as follows: 1. A total of 15 bands were identified from electrophoregrams of respective developmental stages. Of them, 5 bands were recognized throughout the developmental stages. 2. The number and protein amount of identified bands changed according to the worm development from 4 weeks to 12 weeks. However, tLe bar::ding patterns of 4 and 6 week-old worms and 8 and 10 week-old worms were similar each other. 3. Of 15 identified bands, Band 1 was recognized only in 12 week-old worms whereas Bands 3, 4, 8, 9, 10, 11 and 15 gradually lowered their amount according to dcvelor:ment to disappear in 12 week-old. In addition, Band 5 became a major band in 12 week-old while Band 6 turned to a minor band at the same age. The possible relations of changing patterns of protein bands with worm development were discussed.

• Proceedings of the KSAR Conference
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.72-72
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• 2003

대부분의 동물에서 체내 또는 체외수정란의 체외 배양 시 일정한 발육 단계까지 발달한 후 발육지연이나 정지가 되는 체외 발육억제 현상이 나타나게 된다. 특히 돼지에서는 타 가축들과는 달리 4 세포기에서 체외 발육억제 현상이 일어나기 때문에 체외에서의 발육율이 매우 낮아 수정란 생산이 제한되고 있다. 따라서 본 연구는 이러한 돼지 체외발육 억제 현상을 극복하고 돼지 체외 수정란의 체외배양 체계의 기초 자료를 얻고자 돼지 미성숙 난자를 체외에서 성숙, 수정시킨 뒤, 체외 수정란의 배양 시 성장인자와 6탄당의 첨가에 따른 체외 발육율을 검토하였다. 난자의 핵 성숙과 세포질 성숙 및 세포 기능에 영향을 미치는 것으로 알려져 있는 성장인자로는 Insulin-like growth factor-I(IGF-I)과 Epidermal growth factor(EGF)를 사용하였고, 여러 종의 번식기관에 존재하여 배반포 형성을 촉진시키는 것으로 알려진 glucose, mannose, galactose 및 fructose가 6탄당으로 사용되었다. 체외수정란의 발육을 위한 기본 배양액인 NCSU-23에 각각 0, 1, 5, 10 및 20ng/ml의 IGF-I과 EGF를 각각 첨가하여 농도의 차이에 따른 발육율을 검토하였다. 또한 5.56mM의 glucose, mannose, galactose 및 fructose에 5ng/ml의 IGF-I 또는 10ng/ml의 EGF 첨가 유, 무에 따른 초기배 발육율을 검토하였다. 마지막으로, 각각의 6탄당에 위와 같은 농도의 IGF-I와 EGF 공동 첨가 유, 무에 따른 초기배 발육율을 검토하였다. 그 결과 돼지 체외 수정란의 체외 발육 시 배양액 내에 서로 다른 농도의 IGF-I과 EGF를 첨가하였을 때 IGF-I은 5ng/ml(12%)에서, EGF는 10ng/ml(10%)의 실험구에서 가장 높은 배반포기 배의 발육율을 나타냈다. 또한 각각의 6탄당과 IGF-I 또는 EGF 유, 무에 따른 초기배 발육율을 검토한 결과 IGF-I과 EGF 모두 glucose 첨가 시 타 첨가구에 비해 초기 발육 단계의 수정란 발육뿐만 아니라 배반포까지의 배발육(10～11%)이 타 첨가구(3～8%)에 비해 높게 나타났다. 한편, 각각의 6탄당이 첨가된 배양액 내에 IGF-I파 EGF 공동첨가 유, 무에 따른 초기배 발육율을 검토한 결과 모든 실험구에서 EGF와 IGF-I 첨가 시 무첨가보다 높은 초기 배 발육율을 나타냈으며 특히 초기 분열단계 수정란에서는 발육의 차이가 크게 나타났다. 본 연구 결과 성장인자와 6탄당의 첨가는 돼지 수정란의 체외배양 시 초기배 배발육에 효과적인 영향을 미치는 것으로 사료되며, 이는 체외 발육율이 타 가축에 비해 낮은 돼지의 수정란 생산에 있어 체외배양체계의 개선을 위한 기초자료가 될 수 있을 것이라 기대된다.

• Parasites, Hosts and Diseases
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• 제32권4호
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• pp.277-280
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• 1994

In the definitive hosts, metacercariae of Parofonimn westermani excyst in host duodenum, penetrate intestinal wall, migrate peritoneal and thoracic cavities, and develop to sexual maturity in 8 weeks. This study was undertaken to examine the age of the maturing p. westernnni when their infectivity to the other definitive hosts was retained. On 3, 7, 10, 14,21 and 28 days after feeding the metacercariae to cats through a gastric tube, the developing worms were harvested. The juveniles of different age were fed again to other experimental cats. One to 12 weeks after the oral-transfer infections, the experimental cats were examined for establishment of infections. In the cats to which 3- day and 7-day old juveniles (grown up to 1.4 mm long) were fed, 31.4% and 22.6% of the transferred worms were found infected. The worms of 10-28 days old were not infective. Early maturing stages grown up to 7 days maintained their infectivity to the other definitive hosts.

• Parasites, Hosts and Diseases
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• 제33권4호
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• pp.365-376
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• 1995

Antigenic localization in Parofonimn iloktsuenensis worm tissues (tegument, intestine and vitelline gland) in different developmental stages of 2 weeks, 3 weeks, 4 weeks, 5 weeks and 33 weeks from albino rats (Sprague-Dawley) infected with P iloktsuenensis was observed by electron microscopy. These worm tissues of different developmental stage of R iloktsuenensis was observed on electromicrograph by immunogold labeling method using R iLoktsuenensis infected rat serum of 10 weeks. Antigenic localization was demonstrated as labeling of gold particles in tissues on electronmicrograph. In tegument, gold particles were labeled on tegumental tissue, generally more numerous on secretory granules in tegumental syncytium 2 weeks than those on the other elder developmental stages, but there was a little variation in antigenicity according to individual worm tissue. In general, antigenicity in tegumental tissue was not strong (gold particles: 0.1-5/1 Mm2). In intestine, a large number of gold particles (15-18/1 Mm2) were labeled in intestinal epithelium. Gold particles were concentrated especially on secretory granules in cytoplasm, and gold particles were labeled not only in cytoplasmic protrusions, but also in intestinal luminal contents. Intencity of labeling of gold particles was not correlated with developmental stage of worms. In vitelline gland, a large number of gold particles were labeled on vitelline globules. The gold particles in vitelline globules (8- 11/1 Mm2) were concentrated in protoplasm among segmental globules . Key words: Pnragonimus iloktsuenensis, immunogold labeling method, tissue antigen ultrastructure.