Science. 1994 Jul 15;265(5170):402-4. doi: 10.1126/science.265.5170.402.
Nematocysts (cnidocysts) are exocytotic organelles found in all cnidarians. Here, atomic force microscopy and field emission scanning electron microscopy reveal the structure of the nematocyst capsule wall. The outer wall consists of globular proteins of unknown function. The inner wall consists of bundles of collagen-like fibrils having a spacing of 50 to 100 nanometers and cross-striations at intervals of 32 nanometers. The fibrils consist of polymers of "mini-collagens," which are abundant in the nematocysts of Hydra. The distinct pattern of mini-collagen fibers in the inner wall can provide the tensile strength necessary to withstand the high osmotic pressure (15 megapascals) in the capsules.
刺丝囊（刺细胞）是所有刺胞动物中都有的细胞外泌细胞器。本文通过原子力显微镜和场发射扫描电子显微镜揭示了刺丝囊囊壁的结构。外壁由具有未知功能的球状蛋白组成。内壁由胶原样原纤维束组成，其间距为 50 至 100 纳米，每隔 32 纳米有横纹。原纤维由“微胶原”的聚合物组成，微胶原在水螅的刺丝囊中含量丰富。内壁中微胶原纤维的独特模式可以提供承受囊内高渗透压（15 兆帕）所需的拉伸强度。
