잠시만 기다려 주세요. 로딩중입니다.

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

Animal Cells and Systems 2020년 24권 5호 p.299 ~ 310
문명진, Tillinghast Edward K.,
소속 상세정보
문명진 ( Moon Myung-Jin ) - Dankook University Department of Biological Sciences
 ( Tillinghast Edward K. ) - University of New Hampshire Department of Biological Sciences

Abstract


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.

키워드

Ampullate gland; Araneus cavaticus; fine structure; molt; spider silk

원문 및 링크아웃 정보

등재저널 정보