• 한국수산과학회지
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• 제9권1호
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• pp.35-42
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• 1976

1974년부터 1975년 말까지 부안만 대합에 기생하는 흡충류 유충의 발육, 기생율, 조직변화 및 사육실험을 통하여 대합의 폐사원인을 밝혔다. 1. 대합의 생식소, 중장선, 새엽에 기생하는 유모 cercaria인 Cercaria pectinata Huet와 그 sporocyst를 검출하였다. 2. 기생충의 수와 량이 급히 증가하므로 흡충류에 기생된 대합은 기능장해를 받아 폐사된다. 3. 부안산 대합 2,639개체에 대한 대합에 기생되는 흡충의 평균 기생율은 $13.2\%$였는데, 월별로 보면 7월이 가장 높았으며$(29.6\%)$, 3월이 가장 낮았다$(2.0\%)$. 한편 각장에 관계없이 기생율은 거의 같았다. 4. 흡충류에 기생된 대합의 생식소는 거세되고, 유충의 증식으로 중장선은 압박을 받으며 새판내에 기생되므로 혈액순환장해를 일으킨다. 5. 수조 내에서 사육한 기생패는 35일만에 전부 폐사했다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권7호
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• pp.980-985
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• 2000

Influences of Japanese green tea powder (GTP) supplementation to commercial diet on laying performance and egg quality were studied by using 60 laying hens. The experimental diet with or without 0.6% GTP was given ad libitum to the birds during the period from 6 to 71 weeks of age. The birds started egg production from 21 wk of age regardless GTP feeding. Body weight, feed intake, egg weight tended to decrease with GTP supplementation, while egg production rate tended to increase. Haugh unit score was significantly increased with GTP, which accompanied with the increased albumen height. These were observed almost throughout the laying period over 50 wk. Gel proportion in thick albumen was decreased as storage time is prolonged, then higher values of the gel proportion were recorded in the eggs from GTP group. Thick albumen of the eggs from GTP-fed layers had more carbohydrate than that from control layers. All these indicate physical stability of thick albumen in the eggs from GTP group. Thiobarbituric acid content of egg yolk tended to remain lower in the eggs from GTP group during 5-10 days of storage at room temperature. Levels of egg yolk cholesterol and yolk lipid were significantly reduced by GTP feeding. There were no significant differences in eggshell weight, shell thickness and shell strength between the two groups. Thyroid gland and liver from hens slaughtered at 71 wk of age did not differ in weight irrespective of GTP feeding. The present results suggest that GTP could modify components of edible part of egg, leading to the characteristics favourable to consumers such as high durability of thick albumen and less cholesterol in yolk, without altering general performance of the layers throughout this year round experiment.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.79-83
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• 2002

The wild silkmoth, Actias gnoma was firstly collected at Suwon located in the middle part of Korea. The developmental and morphological characteristics of A. gnoma reared under the laboratory conditions were analysed. The egg shape was shorter elliptic. The major and minor diameter of the eggs were 2.04 mm and 1.83 mm, respectively. White mucous material was remained inside the eggs after hatching. Also, the body color of the larvae was completely changed from dark brown to light yellowish-green at the 3rd instar, but it did not occur until pupation. In the feeding test on several plants, the oak tree, Quercus acutissima, was newly identified as a host plant. The final larval instar was mostly 6th, but in some larvae it was 7th. A few of larvae ate their own casts just after ecdysis. The whole larval duration ranged from 45 to 59 days. The single cocoon weight, cocoon shell weight and cocoon shell percentage were 1.65 g,31.3 cg and 18.9%, respectively, The cocoon shape and color were spindle and light brown, respectively. The morphology of the silk gland was greatly different from those of Bombyx mori, Antheraea yamamai and Antheraea peryi: the thickness of the middle and posterior silk glands was almost identical.

• Ocean and Polar Research
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• 제36권2호
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• pp.121-134
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• 2014

이 연구에서는 조직학적 방법을 이용하여 산란 기간 중, 지중해담치의 조직학적 변화를 관찰하였다. 조직학적 관찰 결과, 마산만 지중해담치(M. edulis galloprovincialis)는 4월부터 산란을 시작하여 9월까지 산란이 지속되는 것을 관찰할 수 있었으며, 동일 시기에 비만도도 감소하는 것을 확인할 수 있었다. 소화맹낭 위축도는 산란 스트레스를 받는 6월($3.24{\pm}1.16$)과 수온이 높은 9월($3.33{\pm}1.19$)에 높은 위축도 지수를 보였다. 또한 이 시기(9월)에는 높은 소화맹낭 조직붕괴 현상도 동반되는 것을 관찰할 수 있었다. 병리학적 증상 관찰 결과, 종양증 또한 관찰되었으나, 그 발병률은 5% 미만으로 낮게 나타났다. 마산만의 지중해담치에서는 기생성 병원체는 관찰되지 않았으나, 공생요각류가 관찰되었다. 이 연구에 쓰인 조직병리학적 분석기법은 향후 담치의 건강도 및 연안 환경변화가 주변 생물에게 미치는 영향을 평가하는데 있어 유용하게 활용될 것으로 예측되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.111-115
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• 2004

Nutrition plays an important role in maintaining the larval health, cocoon quality and reproductive potential in Antheraea mylitta D. Nutritional efficiency greatly influenced if food is not adequate and of quality. A. mylitta silkworms were subjected to food deprivation for the period of 0 hr to 12 hrs /day to assess its effect on various nutritional parameters and indices, and its manifestation at different levels. Food ingesta, digesta, gain in body weight declined significantly at each level of deprivation, so also food utilization efficiency like consumption index (CI), growth rate (GR), approximate digestibility (AD), and efficiency of conversion of ingested food (ECI). This stress leads to decline in mean daily food ingesta by 16.73% to 39.76% and digesta by 28.98% to 54.01 % following a significant reduction in average daily body weight gain (27.68% to 55.09%). Food deprivation a1so caused significant loss in the silk gland weight, cocoon and shell weight (14.37% to 53.69%), lowered the fecundity (35.86 % to 83.59%) and in number of eggs laid per gram body weight, but simultaneously the number of non-chorionated eggs increased significantly.

• 한국패류학회지
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• 제4권1호
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• pp.30-41
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• 1988

The gonadal development, the annual reproductive cycle and the first sexual maturity of surf clam, Mactra veneriformis Reeve were studied histologically. Speciemens were monthly collected at the intertidal zone of Naechodo, Chollabuk-do, Korea, for one year from March 1986 to February 1987. Sexuality of the clam is dioecious. The gonads were located between the subregion of mid-intestinal gland in the visceral cavity and the reticular connetive tissues of the foot, The ovary is composed of a number of ovarian sacs, and the testis comprise several testiculat lobules. The undifferentiated mesenchymal tissues and eosinophilic granular cells function as nutritive cells in the early stage. The ripe eggs were about 50-60${\mu}{\textrm}{m}$ in diameter, and they were wurroundedby the gelatinous membranes. The spawing period was from early June to September the main spawning occurred beetween July and August when the water temperature reached above 24$^{\circ}C$. The annual reproductive cycle of this species could be classified into five successive stages: multiplicative(January to March), growing(March to May), mature(April to August), spent(June to September), degenerative and resting(September to February). The monthly changes of fatness coefficient closely correlated with the annual reproductive cycle. Percentages of the first sexual maturity of female and male clams were over 50% among those individals ranging from 2.1 To 2.5cm, and 100% in those over 2.6cm in shell length.

• 한국수산과학회지
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• 제33권6호
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• pp.533-540
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• 2000

1998년 7월부터 1999년 6월까지 전라북도 부안군 대항리 앞바다의 조간대에서 매월 채집한 눈알고둥, Lunella coronsta coreenisis의 생식소발달, 생식세포형 성, 생식주기, 생식소지수, 육중량비 및 군성숙도를 조직학적으로 조사하였다. 눈알고둥은 자웅이체였으며, 생식소는 패각 내의 후반 나선부에 위치하는 간장의 표면에 넓게 분포하였다. 난소와 정소는 각각 수많은 난자형성소엽과 정자형성소낭으로 구성되어 있었다. 생식소지수의 월별 변화는 수온이 상승하는 3월 ($23.86{\pm}3.73$)부터 서서히 증가하여 7월 ($49.76{\pm}6.47$)에 최고치를 나타낸 후, 9월($15.58{\pm}2.33$)에 급격하게 감소하였다. 육중량비의 월별 변화는 $25.2{\%}{\~}32.3{\%}$로, 생식소지수의 월별 변화와 유사한 양상을 나타내었다. 각고 $5.9 mm$ 이하의 개체군은 재생산에 전혀 참여하지 않았으며, $7.0{\~}7.9 mm$의 개체군은 암수 각각 $84.6{\%}$ 와 $91.7{\%}$가 재생산에 참여하였고, 8.0 mm 이상의 개체군은 $100{\%}$ 참여하였다. 생식소의 발달, 생식세포형성과정, 조직분화과정 및 세포학적 특성에 따라, 생식주기는 초기활성기 (12월${\~}$4월), 후기활성기 (1월${\~}$7월), 완숙기 (5월${\~}$8월), 산란기 (7월${\~}$9월) 및 회복기 (9월${\~}$3월)등의 연속적인 5단계로 구분되었다. 산란은 수온이 $24.8^{\circ}C$ 이상인 7월과 9월 사이에 일어나며, 주산란은 8월이었고 성숙란의 직경은 $150{\~}160 {\mu}m$이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.695-701
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• 1999

The hypothalamus is the classic site of synthesis of arginine vasotocin as neurohypophyseal hormone in the chicken. However, high concentrations of arginine vasotocin were also measured in ovarian tissues by radioimmunoassay. At first, we observed specific positive signal of mRNA encoding AVT in the hypothalamus by Northern hybridization. However, we could not find any specific bands in ovarian and uterine tissues. For evidence of transcription of the arginine vasotocin gene ingonadal tissues of the chicken, this study has applied the polymerase chain reaction as a highly sensitive assay. The hypothalamus, the four largest preovulatory ovarian follicles and the shell gland (uterus) were collected at 4 h and 20 h before oviposition. The ovarian follicular tissues were separated into granulose theca interns and theca externa layers. The uterine tissues were separated into myometrium and endometrium The extracted mRNA was converted to cDNA by reverse-transcriptase using oligo-$d(T)_{15}$ primer. Then, the cDNA was amplified by Vent polymerase and arginine vasotocin specific primers. The amplification reaction was incubated by 30 cycles successively, $95^{\circ}C$, $55^{\circ}C$ and $72^{\circ}C$ earth for 1 min. Te comparisons of the mRNA levels encoding arginine vasotocin between the tissues were determined by semi-quantification methods. After amplification of the cDNA, the PCR products were detected in hypothalamus, ovarian tissues and uterine tissues. The results of semi-quantification showed that the levels of arginine vasotocin mRNA in ovarian iud uterine tissues were about from 1/50 to 1/1000 when compared to that in the hypothalamus. The very low levels of mRNA encoding arginine vasotocin in ovarian and uterine tissues probably led us to conclude that arginine vasotocin may play a role of local mediate acting autocrine and/or paracrine.

• 한국수산과학회지
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• 제33권3호
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• pp.184-191
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• 2000

포항 형산강 하구에 서식하는 참재첩, Corbicula leana을 대상으로 생식세포 형성과정 및 생식주기를 조직학적으로 조사하였다. 참재첩은 자웅이체로서 난생이며, 생식소는 완숙하면 암컷은 흑갈색, 수컷은 유백색을 띤다. 생식소관은 내장낭의 간중장선 하방으로 부터 근충의 외벽근층내에 있는 섬유성 망상결체조직까지 분포되어 있다. 난소는 수지상으로 연결된 난소소관으로 구성되어 있고, 정소 역시 많은 소관상의 정소소관으로 구성되어 있는데 이들 소관의 내강상피가 생식상피 기능을 하고 있다. 성숙난모세포는 배포의 변화로 알 수 있으며, 그 크기는 $70{\~}80{mu}m$ 정도이다. 난소 및 정소의 초기 발달에는 간충조직과 색소과립세포들이 영양세포로 관여하고 있으며 난소와 정소가 발달하면서 점차적으로 사라진다. 생식소 발달은 수온과 밀접한 연관성이 있고, 비만도의 변화도 주기성이 일치하였다. 생식주기는 분열증식기, 성장기, 성숙기, 방출기, 퇴화기 그리고 회복기 둥의 연속적인 주기로 구분할 수가 있다. 산란기는 6월 하순부터 9월 중순까지이고, 산란성기는 7월과 8월이었으며 생물학적 최소형은 10.0 mm 이상으로 조사되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제23권1호
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• pp.107-113
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• 2011

Infection effect of $Nosema$ $bombyics$ on the midgut of silkworm $Bombyx$ $mori$ and subsequent appearance of spores and the performance of larvae was studied. Autopsy of larvae showed white pustules on the surface of midgut at 5 days of post infection (pi). At later stage, important organs like midgut, silk gland and gonads reduced in size and all these organs showed white pustules. Light microscope observation of pustules revealed enormous spores. Spore multiplication was at a faster rate in young larvae. Infection of the adult larvae resulted in pebrinized pupa and moths. Larval weight, cocoon weight and cocoon shell ratio reduced as the post infection period increased. Transverse sections of midgut showed $N.$ $bombycis$ infection limited to a few columnar cells at 3-5 days of pi. At 7 days pi, cell volume increased, cells were swollen and elongated. Heavily infected cells looked like sacks filled with parasite and the apical region of certain cells were bulging into the gut lumen. Later at 8-9 days of pi, spores or its developing stages leaked into the lumen either freely or enclosed within the globules of host cytoplasm. Besides columnar cells, development of $N.$ $bombycis$ was observed in the regenerative cells and rarely in goblet cells. Development of $N.$ $bombycis$ was also observed in both longitudinal and circular muscles at the late pi period. The histopathological changes, deformities and spore production time in the host were all influenced by the spore dosage and age of the host.