• Animal cells and systems
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• 제12권2호
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• pp.109-116
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• 2008

Among the four kinds of silk glands in the funnel-web spider Agelena limbata, the ampullate gland for dragline silk production is the most predominate one in both sexes, and is composed of three functional parts-excretory duct, storage ampulla and convoluted tail regions. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another two pairs of minor ampullate glands supply the middle spinnerets. There are no apparent differences between the major and minor ampullate glands not only the external spigots but also their internal silk glands. However, the microstructure is very unique in this spider, because each gland has spherical shaped storage sac with twig-like branched tails. Nevertheless, the wall of the secretory region is similarly composed of a single layer of epithelial cells. The mature secretory silks in glandular epithelium are closely packed and accumulated as electron-opaque vesicles. Most of the secretory products which originated from the rough endoplasmic reticula(rER) are grown up by fusion with the surrounding small vesicles however, the Golgi complex does not seem to play an important role in this process of secretion.

• Applied Microscopy
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• 제50권
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• pp.16.1-16.11
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• 2020

Silk is produced by a variety of insects, but only silk made by terrestrial arthropods has been examined in detail. To fill the gap, this study was designed to understand the silk spinning system of aquatic insect. The larvae of caddis flies, Hydatophylax nigrovittatus produce silk through a pair of labial silk glands and use raw silk to protect themselves in the aquatic environment. The result of this study clearly shows that although silk fibers are made under aquatic conditions, the cellular silk production system is quite similar to that of terrestrial arthropods. Typically, silk production in caddisworm has been achieved by two independent processes in the silk glands. This includes the synthesis of silk fibroin in the posterior region, the production of adhesive glycoproteins in the anterior region, which are ultimately accumulated into functional silk dope and converted to a silk ribbon coated with gluey substances. At the cellular level, each substance of fibroin and glycoprotein is specifically synthesized at different locations, and then transported from the rough ER to the Golgi apparatus as transport vesicles, respectively. Thereafter, the secretory vesicles gradually increase in size by vesicular fusion, forming larger secretory granules containing specific proteins. It was found that these granules eventually migrate to the apical membrane and are exocytosed into the lumen by a mechanism of merocrine secretion.

• Animal cells and systems
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• 제13권2호
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• pp.153-160
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• 2009

The fine structural characteristics of the silk spinning apparatus in the titanoecid spiders Nurscia albofasciata have been examined by the field emission scanning electron microscopy (FESEM). This titanoecid spiders have a pair of medially divided cribella just in front of the anterior spinnerets, and the surface of the cribellum is covered by hundred of tiny spigots which produce numerous cribellate silk fibrils. The cribellar silks are produced from the spigots of the sieve-like prate. and considered as a quite different sort of catching silk with dry-adhesive properties. The other types of the silk spigots were identified as follows: ampullate, pyriform and aciniform glands. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another 1-2 pairs of minor ampullate glands supply the middle spinnerets. In addition, the pyriform glands send ductules to the anterior spinnerets, and two kinds of the aciniform spigots feed silk into the middle (A type) and the posterior spinnerets (both of A & B types), respectively.

• Animal cells and systems
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• 제2권1호
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• pp.145-152
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• 1998

The spinning apparatus and production of secretory silk from silk gland of the black widow spider, Latrodectus mactans were studied with scanning and transmission electron microscopes. The silk glands were located in seven groups on the spinnerets including each pair of major and minor ampullate, 3 pairs of tubuliform, 1 pair of flagelliform, 2 pairs of aggregate, about 50 pairs of pyriform and over 250 pairs of aciniform glands, respect- ively. Each group of silk gland feeds silk into one of the three spinneret pairs. Secretory silk is synthesized from rough endoplasmic reticulum (rER) of glandular epithelial cells. The secretory silk is transported from toe rER into the secretory vacuoles which are grown up by fusion with the surrounding small vesicles including the secretory silk. The secretory vacuoles, which show a gradual increase in electron density with the process of maturity, are formed without involvement of the Golgi complex, suggesting that they do not play an important role in the processing of the secretory silk. The secretory silk products are released by the mechanism of apocrine secretion, losing part of their cytoplasm. Moreover, another type of silk precursor, possibly protein, appears as granular material, and is also discharged to the luminal cavity.

• 한국응용곤충학회:학술대회논문집
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• 한국응용곤충학회 2001년도 합동 춘계 학술발표회
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• pp.49-49
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• 2001

• 한국동물학회:학술대회논문집
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• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
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• pp.134.2-134
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• 1996

No Abstract, See Full Text

• Applied Microscopy
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• 제33권4호
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• pp.315-323
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• 2003

들풀거미(Agelena limbata) 실크 분비장치의 방적돌기와 토사관의 미세구조를 고배율의 전자현미경으로 관찰하고, 그 형태적 특성을 분석하였다. 세 쌍의 방적돌기 중에서 전 및 후방적돌기는 각각 2개의 마디로 구성되어 있는 반면, 중방적돌기는 단일 마디로 이루어져 있었으며, 특히 후방적돌기는 후방으로 매우 신장되어 있음이 관찰되었다. 방적돌기 표면에 형성된 토사관은 병상선(ampullate gland), 관상선(tubuliform gland), 이상선(pyriform gland), 포도상선(aciniform gland) 등, 4종류로 구성되어 있었다. 병상선의 토사관은 전방적돌기와 중방적돌기 표면에 각 2쌍씩이 형성되어 있었고, 암컷에서만 관찰되는 관상선의 토사관은 중방적돌기와 후방적돌기에서 관찰되었다. 또한 이상선의 토사관은 전방적돌기에서 그리고 포도상선의 토사관은 중 및 후방적돌기에서 확인되었다. 방적돌기 방적면에 형성된 토사관은 공통적으로 기저마디와 말단마디로 구성되어 있었는데, 포도상선의 토사관은 기저마디에 비해 말단마디가 매우 신전된 특징을 지니고 있음이 확인되었다.

• Applied Microscopy
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• 제42권2호
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• pp.67-76
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• 2012

고강성 나노섬유 생산이 가능한 전기방사장치 방사노즐의 설계를 위해 자연을 모방하는 공학적 방법론을 도입하여, 무당거미(Nephila clavata L.Koch) 대병상선의 토사관과 그 생체방적 시스템이 지닌 미세구조적 특성을 고해상도의 전자현미경 관찰을 통해 분석하였다. 자연계에서 가장 강도가 높은 드래그라인을 생성, 분비하는 대병상선의 토사관은 bullet type spigot을 통해 전방적돌기 표면에 개구되어 있었으며, 신축성 구조를 지닌 토사관 말단마디의 노즐을 통해 고체상의 실크가 생성되었다. 분비낭과 토사관 사이를 연결한 분비관은 루프를 형성한 후 방적돌기에 수납되었고, 분비관 내강의 직경은 점진적으로 축소되어 노즐을 통해 방사되는 실크의 직경은 펀넬 부위의 1/10 이하인 것으로 관찰되었다. 한편, 실크 중합과정에서 수분을 제거하기 위한 큐티클의 특수구조가 관찰되었는데, 분비낭의 펀넬 부위에서는 해면상 큐티클 구조가 그리고 분비관의 말단부에서는 비후된 subcuticle 구조와 함께 잘 발달된 상피의 미세융모 층이 확인되었다. 또한 분비관의 내강부 큐티클 표면에서 확인된 나선형 강선구조는 실크 전구물질의 신속한 유동을 촉진하는 장치일 것으로 해석되었다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.180.2-180
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• 2000

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.156.1-156
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• 2003

No Abstract, See Full Text