• Animal cells and systems
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• v.12 no.2
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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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• v.33 no.4
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• pp.315-323
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• 2003

The fine structural characteristics of the spinnerets and spigots of the silk producing apparatus in the adult funnel-web spider, Agelena limbata, were analysed with the light and scanning electron microscopes. Silk producing apparatus of this spider was composed of three pairs of spinnerets (anterior, median, posterior) and four different types of spigots-ampullates, tubuliforms, pyriforms and aciniforms. By the examination of their ultrastructural characteristics, it has been revealed that each spigot on the spinnerets are connected through the typical silk gland within abdominal cavity. Among the three pairs of spinnerets, the posterior pairs were highly elongated and has most characteristic features. Two pairs of large ampullates were connected to anterior spinneret and another two pairs of small ampullates to median spinnerets. Spigots of the tubuliforms were observed only in female and were connected both of median and posterior spinnerets respectively. While spigots of the pyriforms were connected on the anterior spinnerets but aciniforms on both of median and posterior spinnerets respectively.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.05a
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• pp.49-49
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• 2001

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.11a
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• pp.164-164
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• 2001

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.103-103
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• 2002

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.106-106
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• 2002

• Proceedings of the Zoological Society Korea Conference
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• 2001.04a
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• pp.67.2-67
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• 2001

No Abstract, See Full Text

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.11a
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• pp.105-105
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• 2001

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.315-318
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• 2007

Cooperative or non-territorial permanently social spiders are believed to have evolved from species showing subsocial maternal care. The transition from subsocial to cooperative social groups probably involved a transition from an outbreeding breeding system to one with inbreeding. Nepotistic recognition among siblings should facilitate the evolution of social cooperation through avoidance of inbreeding and maintenance of mutual tolerance between siblings. We conducted experiments to determine whether a mechanism for sibling recognition is present in the subsocial spider, Coelotes terrestris which displays extended maternal care in the form of food provisioning. The numbers of surviving individuals within unfed groups were observed and compared between non-sibling groups of ten spiderlings and groups of ten siblings. The number of survivors differed significantly between groups, with consistently fewer spiderlings surviving in the non-sibling groups than the sibling groups over the study period. This result suggests that sibling recognition and nepotism do occur in this subsocial species. The nepotism involved in the maternal social organization of the Coelotes might be an example of a preadaptation facilitating the evolution of permanent social life.

• Applied Microscopy
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• v.42 no.2
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• pp.67-76
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• 2012

The biomimetic approach on the cuticular spinning nozzles of the major ampullate silk glands in the golden-web spider Nephila calvata has been attempted using various visualizing techniques of light and electron microscopes to improve the design of spinning nozzle for producing synthetic nanofibers spun from electrospinning apparatus. The major ampullate spigot which has the most effective nozzle system to produce nanofibers for dragline silk with high strength and elasticity is connected via the bullet type spigot on anterior spinneret with flexible terminal segment. The excretory duct which transports the liquid silk feedstock from ampulla to spigot is divided into 3 limbs by loops back on itself to form an S-shape morphology that is bundled in connective tissue. Final diameter of the nanofibers at nozzle was dramatically reduced by gradual narrowing of duct cuticle less than 10 times comparing to its original size of funnel region. Moreover, the funnel has a characteristic cuticular organization with porous microstructure which seems to be related to water removal from feedstock of silk precursors. High magnification electron micrographs also reveal the presence of the spiral grooves on the surface of the cuticular intima near the valve which presumed to reduce friction during rapid flow of liquid silk.