Immunoreactivity of Glutamic Acid Decarboxylase (GAD) Isoforms in the Central Nervous System of the Barn Spider, Araneus cavaticus

문명진,EdwardK.Tillinghast 한국곤충학회 2013 Entomological Research Vol.43 No.1

The γ‐aminobutyric acid (GABA) has long been considered as an inhibitory neurotransmitter in the central nervous system (CNS) of both vertebrates and arthropods. Since the glutamic acid decarboxylase (GAD) has a restricted tissue distribution and catalyzes the conversion of L‐glutamate to GABA, immunoreactivity of GAD isoforms can reveal distribution of GABAergic neurons in the CNS. In the CNS of the spider Araneus cavaticus, immunoreactivity of GAD isoforms can be detected in the optic lobes including neurons and neuropiles of the supraesophageal ganglia. Strong GAD‐like immunoreactive cell bodies are concentrated in two bilaterally symmetric cell clusters of the protocerebrum. Some intrinsic cell bodies near the central body also show strong immunoreactivity. However, the intrinsic nerve masses and some of the longitudinal and transverse tracts within the supraesophageal ganglion are only lightly labelled, and the fibers transverse the hemisphere and the central fibrous masses are not labelled. Among the three basic types of cell bodies surrounding the central body, several clusters of the Type‐C cells show strong GAD‐like immunoreactivity, however both of the Type‐A and Type‐B cells are not labelled at all.

Molt-related changes in the major ampullate silk gland of the barn spider Araneus cavaticus

문명진,EdwardK.Tillinghast 한국통합생물학회 2020 Animal cells and systems Vol.24 No.5

Spiders molt periodically before reaching full maturity, but several spiders continue to molt after sexual maturity. This post-maturity molting (PMM) behavior has been observed in the barn spider Araneus cavaticus (Araneae: Araneidae) among the orb-web spiders. In this study, we investigated molt-related changes in the ampulla and tail regions of the major ampullate gland during the PMM sequences (intermolt, pre-molt, ecdysis, and post-molt). The results showed that all gland units consist of a monolayer of epithelial cells surrounding a large central lumen, and two types of secretory granules (Type-M and Type-S). During the molting period, most cells showed fine structural modification in their organelles, and conspicuous tissue swelling was detected at the glandular epithelium. Following the molting cycle, the amount of Type-M granules continues to increase in the cell with a corresponding swelling, but Type-S granules gradually disappeared during the process of ecdysis. This suggests that the molt-related changes in spider silk production originates from the periodic production of Type-S secretory granules in the ampulla region. As Type-M granules flow toward the funnel, it is coated with viscous liquid secretion of Type-S granules in order to produce dragline silk fibers. We provide fine structural evidence for Type-S granules of hexagonal crystalline substructures representing glycoprotein substances to maintain high level of water content.

Fine Structure of the Glandular Epithelium during Secretory Silk Production in the Block Widow Spider Latrodectus mactans

Moon, Myung-Jin,Tillinghast, Edward-K. The Korean Society for Integrative Biology 2002 Korean journal of biological sciences Vol.6 No.4

Among the silk glands in the black widow spider Latrodectus mactans, the ampullate one is the most predominant gland in both sexes, and is com-posed of three functional parts - excretory duct, storage ampulla and convoluted tail regions. This experiment was performed using mechanical pulling stimulation with electric motor equipment to reveal a correlation between silk usage and silk producing system in this poisonous spider. The mature secretory products in glandular epithelium are closely packed and appear as electron-opaque spherical vesicles. A part of the vesicles with fine fibrillar paracrystalline texture seems to store some proteins which will function at the time of final assembly into fibrils. Most of the secretory silk products which originated from the rough endoplasmic reticula of the glandular epithelial cells are grown by fusion with surrounding small vesi-cles. However, the Golgi complex does not seem to play an important role in this process of secretion. According to progressive maturation of secre-tory silk product, these granules are progressively filled with a fine fibrillar material, and thus appear much more electron-dense than those of earlier states. When the secretory product is extruded from the glandular cavity, the epithelium is rapidly changed to a thinner layer of tall columnar cells with less definitive cell membranes. After extruding there ave a few secre-tory droplets within these cells, thus causing this region to stain much lighter.

Silk Production after Mechanical Pulling Stimulation in the Ampullate Silk Glands of the Barn Spider, Araneus cavaticus

문명진,Edward K. TILLINGHAST 한국곤충학회 2004 Entomological Research Vol.34 No.2

Synthesis of protein by the major ampullate silk glands in the barn spider, Araneuscavaticus was stimulated by depleting the storage of silk protein in the ampulla by mechanicallypulling fiber from the spigot. After this treatment, fine structural changes of the glandular epitheliumduring silk production were examined using light and transmission electron microscopes. Inthe process of rapid production, major secretory silk was synthesized at the tail region via rER ofglandular epithelial cells, and was transported into the ampulla region. The mature secretory productin glandular epithelium appears almost spherical vacuoles which were grown up by fusion withthe surrounding small vesicles including the secretory silk. Unlike to a typical process of the secretion,the ampullate silk of tail region seems to bypass either concentrating or packaging steps bythe Golgi apparatus. However there s no doubt that the Golgi apparatus also play an important rolein the secretory process of the ampulla region. After mechanical pulling stimulation, both epitheliaof ampulla and tail regions appeared as a thinner layer of columnar cells with less definitive cellmembrane. There are few secretory droplets within these cells, thus causing this region to stainmuch lighter. It is obvious that the cell loses part of its cytoplasm in this process, and disorganizationof the secretory product occurs when it is extruded from the cells by a apocrine release.

Fine Structure of the Glandular Epithelium during Secretory Silk Production in the Black Widow Spider Latrodectus mactans

Myung-JinMoon,EdwardK.Tillinghast 한국통합생물학회 2002 Animal cells and systems Vol.6 No.4

Fine Structural Analysis of the Changes in Ovarian Epithelium and Egg During Maturation in the Orb-web Spider, Nephila clavata

Hwang Hee-Jun,Tillinghast Edward K.,Moon Myung-Jin 한국응용곤충학회 2002 한국응용곤충학회 학술대회논문집 Vol.2002 No.1

Fine Structural Aspects of the Venom Production in the Black Widow Spider, Latrodectus mactans

문명진,Moon, Myung-Jin,Tillinghast, Edward K. Korean Society of Electron Microscopy 1996 Applied microscopy Vol.26 No.1

검은과부거미의 독 분비장치는 두흉부에 있는 가위턱과 한쌍의 독선으로 이루어져 있다. 독선은 한겹의 얇은 장막과 횡문근 섬유의 다발에 의해 둘러싸여 있었고. 근육층을 따라서 운동신경의 축삭 돌기와 근섬유 사이에 신경근육간 연접이 형성되어 있었다. 분비상피를 이루는 단층 원주상피세포에는 복잡한 수지상의 돌기가 형성되었고, 독선 전체가 단포상선을 이루고 있음이 관찰되었다. 상피의 분비면은 기저막으로부터 선의 내강쪽으로 확장된 세포질 돌기에 의해 표면적이 현저히 증가되었고, 상피의 내강면에는 조밀한 미세융모가 형성되어 있었다. 독성 분비물은 상피세포 내에서 두 종류의 분비과립으로부터 생성되었다. 분비기동안 이들 분비과립은 과적의 형태로 변형, 농축된 후, 이출분비의 형태로 내강으로 방출되었다. 방출 후의 기저부 상피세포들은 고도의 증식과정을 거쳐 원주상의 상피세포로 재생됨이 확인되었다. The venomous apparatus of the black widow spider, Latrodectus mactans, is composed of chelicera and paired venom glands in the cephalothorax. Each glands is surrounded by a thin adventitia and striated muscular bundles resting on a basal membrane. Along the musculature neuromuscular synaptic contacts are formed by a motor axon and the muscle fibers. The secretory epithelium, which made up of simple and long columnar cells with extensive finger-like processes, creates a simple acinar gland. The secretory surfac is increased by a sort of fringes extended from the basal membrane into the gland lumen, and the luminal surface of the epithelium is marked by the presence of closely spaced microvilli. The venoms of the black widow spider are produced from two types of secretory granules within the epithelial cells. During the secretory phase, these granules are transformed into droplets and suffering a condensation. Finally the secretory products are released by the apocrine secretion. After the gland is emptied, the basal epithelial cells present a high proliferative process and regenerate the columnar epithlial cells.

Fine Structure and Immunocytochemical Localization of Glutamic Acid Decarboxylase (GAD) Isoforms in the Central Nervous System of Spiders

Hwang Hee-Jun,Tillinghast Edward K.,Moon Myung-Jin 한국응용곤충학회 2002 한국응용곤충학회 학술대회논문집 Vol.2002 No.1